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Evaluation of Diagnostic Performance of CT for Detection of Tumor Thrombus in Children with Wilms Tumor: A Report from the Children’s Oncology Group
Abstract
Pre-operative assessment of intravascular extension of Wilms tumor is essential to guide management. Our aim is to evaluate the diagnostic performance of multidetector CT in detection of tumor thrombus in Wilms tumor.
The study population was drawn from the first 1,015 cases in the AREN03B2 study of the Children's Oncology Group. CT scans of children with (n = 62) and without (n = 111) tumor thrombus at nephrectomy were independently reviewed by two radiologists, blinded to patient information. Doppler sonography results were obtained from institutional radiology reports, as Doppler requires real-time evaluation. The diagnostic performance of CT and Doppler for detection of tumor thrombus was determined using nephrectomy findings as reference standard.
In the primary nephrectomy group, tumor thrombus detection sensitivity, specificity of CT was 65.6, 84.8%, and Doppler was 45.8, 95.7%, respectively. In this group, sensitivity of CT, Doppler for detection of cavoatrial thrombus was 84.6 and 70.0%, respectively. In the secondary nephrectomy group, tumor thrombus detection sensitivity, specificity of CT was 86.7, 90.6%, and Doppler was 66.7, 100.0%, respectively. In this group, sensitivity of CT, Doppler for detection of cavoatrial thrombus was 96.0 and 68.8%, respectively. Pre-operative Doppler evaluation performed in 108/173 cases, detected 3 cases with intravenous extension (2 in renal vein, 1 in IVC at renal vein level) that were missed at CT.
CT can accurately identify cavoatrial tumor thrombus that will impact surgical approach. Routine Doppler evaluation, after CT has already been performed, is not required in Wilms tumor.
... Both gray-scale and color Doppler images of the renal vein are essential to exclude intravascular extension because tumor thrombus is vascular and can result in a false-negative color Doppler evaluation. If, however, a CT or MRI has already been performed, sonography for vascular extension should be reserved for cases where CT/MRI is equivocal regarding vascular extension of tumor [12]. ...
... Mediastinal and hilar lymph node metastatic disease is uncommon in Wilms tumor as compared to more aggressive renal malignancies such as medullary carcinoma. However, tumor thrombus (contiguous or non-contiguous with primary tumor) is seen in about 11% of Wilms tumor cases and intravenous contrast agent is strongly recommended to best evaluate the vessels [12]. It is essential that the lungs be evaluated prior to nephrectomy because basilar atelectasis and pleural effusions are common in the postoperative state and can preclude adequate evaluation of the lung parenchyma. ...
... These children typically require cardiopulmonary bypass with cavotomy or atriotomy to remove the residual thrombus after chemotherapy. While sonography with Doppler evaluation used to be mandatory for evaluating tumor thrombus, current-generation CT and MRI scanners with high spatial/temporal resolution and multiplanar abilities have high diagnostic accuracy for detecting tumor thrombus, especially when it extends into the IVC above the renal vein [12]. ...
Wilms tumor is the most common pediatric renal tumor, accounting for approximately 7% of all childhood cancers. Imaging plays an important role in the detection, staging, post-therapy evaluation and surveillance of Wilms tumor. Wilms tumor can be detected during surveillance of a known cancer predisposition or after a child presents with symptoms. In this manuscript we describe an evidence-based approach to the initial evaluation of Wilms tumor using current guidelines from the Children’s Oncology Group (COG). We illustrate the COG staging system for pediatric renal tumors and highlight key imaging findings that are critical for surgical management. We also discuss the controversies regarding detection and significance of <5-mm pulmonary nodules at initial staging. And finally, we present some thoughts regarding surveillance of Wilms tumor, where overall survival has now approached 90%.
... Additional data provided by these scans include the status of the contralateral kidney, tumor involvement of the renal veins or inferior vena cava, presence of retroperitoneal adenopathy, preoperative tumor rupture, and the existence of ascites. [9,10] Imaging characteristics, however, are not always correlated with operative or pathologic findings and should not replace surgical exploration and tissue analysis for local and disease staging. [10,11] Advances in imaging such as 3-D computer reformatting and printing models may assist in planning operative approaches, particularly for patients in whom nephron sparing surgery is appropriate. ...
... The renal vein requires evaluation by palpation and/or intraoperative ultrasound to rule out tumor thrombus, which should be resected en-bloc when present, avoiding spillage [19]. CT has been shown to be equally sensitive to doppler ultrasound for diagnosing the presence of thrombus in the renal vein or vena cava [9]. WT is frequently adherent to, but rarely invades, surrounding organs. ...
... Vascular extension above the hepatic veins increases the risk of bleeding complications, and neoadjuvant chemotherapy is currently recommended in cases where the thrombus extends into the retrohepatic cava [13,14,19]. CT and Doppler ultrasound are equally useful for assessing vascular extension to inform presurgical planning [9], but intraoperative IVC and/or renal vein palpation is still essential to avoid transecting an unidentified thrombus. Intraoperative ultrasound can also be utilized if preoperative imaging and intraoperative palpation is unclear at defining the presence or extension of intravascular disease. ...
This article reviews of the current evidence-based treatment standards for children with Wilms tumor. In this article, a summary of recently completed clinical trials by the Children's Oncology Group is provided, the current diagnostic evaluation and surgical standards are discussed, and the surgical impact on current risk stratification for patients with Wilms tumor is highlighted.
Level of evidence:
This is a review article of previously published and referenced LEVEL 1 studies, but also includes expert opinion LEVEL V, represented by the American Pediatric Surgical Association Cancer Committee.
... Heart involvement is, in most cases, limited to the cavoatrial junction or into the right atrium, but the thrombus can also extend through the tricuspid valve into the right ventricle and even then is often asymptomatic and without clinical signs [12,13] infrahepatic IVC may undergo upfront resection in some protocols, while those with retro-hepatic thrombus need more extensive dissection and supra-hepatic IVC control. Neoadjuvant chemotherapy followed by surgery, including cardiopulmonary bypass is required for intracardiac thrombus in all management protocols [14]. Surgical strategy for these patients thus revolves around the distal extent of the thrombus being known, with fewer perioperative complications occurring when the presence and nature of the thrombus is delineated preoperatively [12]. ...
... It is largely thought to be less effective in identifying the thrombus [2]; however, modern multidetector CT technology may offer improved visualization of thrombus. A report from the Children's Oncology Group in 2012 found that CT can accurately identify cavoatrial tumour thrombus, with a concordance rate between CT and surgical findings being 82.7%, and concluded that routine Doppler evaluation after CT may not be required [14]. Magnetic resonance imaging (MRI) (Fig. 2), with its advantages of lack of ionizing radiation, and the ability to evaluate vessels without contrast, may have comparable accuracy in detection of thrombus, but the expense and the requirement for procedural sedation are disadvantageous. ...
... Magnetic resonance imaging (MRI) (Fig. 2), with its advantages of lack of ionizing radiation, and the ability to evaluate vessels without contrast, may have comparable accuracy in detection of thrombus, but the expense and the requirement for procedural sedation are disadvantageous. In addition, MRI is not a routine chest imaging modality employed in these patients due to the poor sensitivity for lung metastases [14]. ...
Purpose:
To review demographics, effect of preoperative chemotherapy on tumour thrombus, imaging, operative strategy, and outcomes of 12 patients presenting with intracardiac extension of Wilms tumour thrombus.
Methods:
A retrospective audit was undertaken on patients with intracardiac extension of Wilms tumour. Patients were identified from the oncology database and information obtained on clinical presentation, stage, preoperative treatment, surgical procedures and complications, histology, and survival status. Ethics approval was obtained from the University of Cape Town Human Research Ethics Committee.
Results:
From 1984 to 2016, 337 children with Wilms tumour were treated. Twelve (3.6%) had intracardiac extension of tumour thrombus, nine into the right atrium, and three into the right ventricle. Ultrasound, computerized tomography, magnetic resonance imaging, and echocardiograms were used to assess thrombus level. Patients were staged as stage III(8) and IV(4). All patients received preoperative chemotherapy. Thrombus retracted from the heart in two cases. One patient died preoperatively. Eleven underwent laparotomy, median sternotomy, and cardiopulmonary bypass (CPB). Four underwent cavectomy. Five required cavoatrial patches. Thrombus extending into the hepatic veins was extracted in five patients. There was one intraoperative complication and one perioperative death. Thrombus histology showed viable tumour in 9 of 11 patients. Three patients died of progressive disease. Seven patients are currently disease free.
Conclusion:
A combination of imaging is required to determine thrombus extent, and this facilitates surgical planning. Preoperative chemotherapy may cause thrombus regression, thus avoiding CPB. CPB offers appropriate conditions for safe tumour thrombus excision. Full management in centres with appropriately experienced staff and facilities for CPB is recommended.
... A discrete filling defect in the renal vein or inferior vena cava in association with distension of the vessel was considered to be a tumour thrombus. If the vessel could not be delineated because of compression by a surrounding mass, venous thrombus was considered to be absent for the purpose of this study [4]. Tumour rupture was considered to be present if there was ascites beyond the cul de-sac, extra-capsular retroperitoneal fluid, or fat stranding around the kidney, with ascites being most predictive of rupture [5,6] Contralateral synchronous lesions were defined as non-cystic lesions of any size in the contralateral kidney [6]. ...
... The treatment protocol is based on the clinical and imaging appearance of the renal tumour, and surgical or pathological evaluation is performed after initial chemotherapy. McDonald et al. [4,11] recently described the benefits of CT and MRI in staging Wilms tumour. CT evaluation has the advantage of faster scanning with less frequent need for sedation, and allows for simultaneous evaluation of the lungs. ...
... When there is no access to cross-sectional images, ultrasound and X-ray images may guide therapy. Thorough disease assessment and planning improve the quality of care and outcome [19][20][21][22][23][24][25][26][27][28][29] ; therefore, access to cross-sectional images in centers providing multidisciplinary pediatric cancer care should be prioritized. The availability of pathologic analyses of frozen sections may also be limited in LMICs. ...
... National cancer centers should be accessible and well connected with a network of primary health and cancer units to deliver affordable, equitable, and high-quality care. The costeffectiveness of treating cancer in centers with higher capabilities was shown in the third edition of Disease Control Priorities.18 operative surgical planning.[19][20][21][22][23][24] Surgeons should develop skills to adequately interpret cross-sectional imaging delineating tumor extent and laterality for surgical planning. ...
Background:
Survival of Wilms tumor (WT) is > 90% in high-resource settings but < 30% in low-resource settings. Adapting a standardized surgical approach to WT is challenging in low-resource settings, but a local control strategy is crucial to improving outcomes.
Objective:
Provide resource-sensitive recommendations for the surgical management of WT.
Methods:
We performed a systematic review of PubMed and EMBASE through July 7, 2020, and used the GRADE approach to assess evidence and recommendations.
Recommendations:
Initiation of treatment should be expedited, and surgery should be done in a high-volume setting. Cross-sectional imaging should be done to optimize preoperative planning. For patients with typical clinical features of WT, biopsy should not be done before chemotherapy, and neoadjuvant chemotherapy should precede surgical resection. Also, resection should include a large transperitoneal laparotomy, adequate lymph node sampling, and documentation of staging findings. For WT with tumor thrombus in the inferior vena cava, neoadjuvant chemotherapy should be given before en bloc resection of the tumor and thrombus and evaluation for viable tumor thrombus. For those with bilateral WT, neoadjuvant chemotherapy should be given for 6-12 weeks. Neither routine use of complex hilar control techniques during nephron-sparing surgery nor nephron-sparing resection for unilateral WT with a normal contralateral kidney is recommended. When indicated, postoperative radiotherapy should be administered within 14 days of surgery. Post-chemotherapy pulmonary oligometastasis should be resected when feasible, if local protocols allow omission of whole-lung irradiation in patients with nonanaplastic histology stage IV WT with pulmonary metastasis without evidence of extrapulmonary metastasis.
Conclusion:
We provide evidence-based recommendations for the surgical management of WT, considering the benefits/risks associated with limited-resource settings.
... It can also appear as a solid round mass, less frequent [4,5]. US is helpful for the establishment of caval permeability and inferior vena cava tumor thrombus [12,13]. We identified one case of nephroblastoma with intravenous extension visible on US, in a two-year-old child. ...
... More CT aspects can comprise of infiltration or distortion of the pyelocalyceal system, vascular extension or lymph node involvement [17]. CT allows appropriate staging of the disorder and identifies the existence of nephrogenic rests (NR) in the renal tissue [13,15]. Abdominal CT can identify the existence of tumor rupture, representing an important risk factor for recurrence of the disease [2]. ...
Background:
Nephroblastoma is the most common renal malignancy in children kidney. They are highly heterogeneous tumors with challenging imagistic and histopathological (HP) differential diagnosis. Imaging is critical for understanding local anatomy, staging and for planning surgical approach.
Purpose:
To determine whether HP staging can be successfully predicted by the imagistic staging using computed tomography. Also, we find it important to make a brief review of the imagistic, HP and immunohistochemical differential diagnosis of nephroblastoma, considering that a correct diagnosis is essential for an appropriate therapeutic strategy in all stages.
Patients, materials and methods:
We present a retrospective study of the medical dossiers of 22 patients that underwent surgery at our Center between 2014 and 2020. We provided descriptive data and compared imagistic and HP staging using a Mann-Whitney U-test. An up-to-date literature review was also done.
Results:
We found that imagistic staging tends to under- or over-stage at similar rates and that the difference between the two staging systems is statistically significant. Immunohistochemistry is necessary for establishing the correct diagnosis, especially in cases with one predominant HP pattern.
Conclusions:
HP and imagistic staging are not yet sufficiently similar for successfully predict the former via imagistic means.
... When there is no access to cross-sectional images, ultrasound and X-ray images may guide therapy. Thorough disease assessment and planning improve the quality of care and outcome [19][20][21][22][23][24][25][26][27][28][29] ; therefore, access to cross-sectional images in centers providing multidisciplinary pediatric cancer care should be prioritized. The availability of pathologic analyses of frozen sections may also be limited in LMICs. ...
... National cancer centers should be accessible and well connected with a network of primary health and cancer units to deliver affordable, equitable, and high-quality care. The costeffectiveness of treating cancer in centers with higher capabilities was shown in the third edition of Disease Control Priorities.18 operative surgical planning.[19][20][21][22][23][24] Surgeons should develop skills to adequately interpret cross-sectional imaging delineating tumor extent and laterality for surgical planning. ...
Survival of Wilms tumor (WT) is >90% in high-resource settings but <30% in low-resource settings. Adapting a standardized surgical approach to WT is challenging in low-resource settings, but a local control strategy is crucial to improving outcomes. Objective: Provide resource-sensitive recommendations for the surgical management of WT. Methods: We performed a systematic review of PubMed and EMBASE through July 7, 2020, and used the GRADE approach to assess evidence and recommendations. Recommendations: Initiation of treatment should be expedited, and surgery should be done in a high-volume setting. Cross-sectional imaging should be done to optimize preoperative planning. For patients with typical clinical features of WT, biopsy should not be done before chemotherapy, and neoadjuvant chemotherapy should precede surgical resection. Also, resection should include a large transperitoneal laparotomy, adequate lymph node sampling, and documentation of staging findings. For WT with tumor thrombus in the inferior vena cava, neoadjuvant chemotherapy should be given before en bloc resection of the tumor and thrombus and evaluation for viable tumor thrombus. For those with bilateral WT, neoadjuvant chemotherapy should be given for 6–12 weeks. Neither routine use of complex hilar control techniques during nephron-sparing surgery, nor nephron-sparing resection for unilateral WT with a normal contralateral kidney is recommended. When indicated, postoperative radiotherapy should be administered within 14 days of surgery. Post-chemotherapy pulmonary oligometastasis should be resected when feasible, if local protocols allow omission of whole-lung irradiation in patients with non-anaplastic histology stage IV WT with pulmonary metastasis. Conclusion: We provide evidence-based recommendations for the surgical management of WT, considering the benefits/risks associated with limited-resource settings.
... A discrete filling defect in the renal vein or inferior vena cava in association with distension of the vessel was considered to be a tumour thrombus. If the vessel could not be delineated because of compression by a surrounding mass, venous thrombus was considered to be absent for the purpose of this study [4]. Tumour rupture was considered to be present if there was ascites beyond the culde-sac, extra-capsular retroperitoneal fluid, or fat stranding around the kidney, with ascites being most predictive of rupture contralateral synchronous lesions were defined as non-cystic lesions of any size in the contralateral kidney [5,6]. ...
... The treatment protocol is based on the clinical and imaging appearance of the renal tumour, and surgical or pathological evaluation is performed after initial chemotherapy. McDonald et al., [4,10] recently described the benefits of CT and MRI in staging Wilms tumour. CT evaluation has the advantage of faster scanning with less frequent need for sedation, and allows for simultaneous evaluation of the lungs. ...
Objective: To compare the diagnostic performance of CT and MRI for local staging of pediatric renal tumours. Materials and Methods: The study population was derived from our hospital Medical College Kolkata and Hospital. Baseline abdominal imaging performed with both CT and MRI.A retrospective review was done with 50 renal tumour cases selected and planned for nephrectomy over a study period of one year from October 2020 to November 2021. Each case was evaluated for capsular penetration, lymph node metastasis, tumour thrombus, preoperative tumour rupture, and synchronous contralateral lesions. The surgical and pathological findings were the reference gold standard. Results: The sensitivity of CT and MRI for detecting capsular penetration was 70% and 60%, respectively (P=0.73), while specificity was 84.3% and 84% (P=1.0). The sensitivity of CT and MRI for detecting lymph node metastasis was 80% and 53% (P=0.22), and specificity was 88% and 92% (P=1.0). Synchronous contralateral lesions were identified by CT in 5/12 cases and by MRI in 8/12 cases. Conclusion: CT and MRI have similar diagnostic performance for detection of lymph node metastasis and capsular penetration. MRI was more accurate in detecting contralateral synchronous lesions; how-ever these were observed in a very a smaller number of cases. Hence either modality can be used for initial loco–regional staging of paediatric renal tumours
... Contrast-enhanced CT can accurately diagnose the intravenous and intra-atrial thrombus as represented by a filling defect seen in contrast-enhanced studies giving a concordance rate of 82.7% between CT and surgical The entire IVC is filled with tumour thrombus extending into the right ventricle. b Axial CT of the chest showing intra-atrial tumour extending into the right ventricle findings and is now reported to be as accurate as Doppler US in the detection of thrombus [40]. While MRI may be advantageous due to the lack of ionizing radiation and vessel clarity, the disadvantages of the requirement for sedation and cost, as well as the fact that MRI is not routinely used for evaluation of lung metastases limits its use [40]. ...
... b Axial CT of the chest showing intra-atrial tumour extending into the right ventricle findings and is now reported to be as accurate as Doppler US in the detection of thrombus [40]. While MRI may be advantageous due to the lack of ionizing radiation and vessel clarity, the disadvantages of the requirement for sedation and cost, as well as the fact that MRI is not routinely used for evaluation of lung metastases limits its use [40]. Echocardiography is highly sensitive in visualizing intracardiac thrombus, assesses cardiac function and is advocated for use in all patients with IVC thrombus [35,41]. ...
The prognosis of children with Wilms tumour has greatly improved since the introduction of adjuvant radiotherapy and chemotherapy more than 70 years ago with a current overall long-term survival approaching 90%. Before this, surgery was the only option with around 20% survival, even in low-risk categories. The focus is now on management options for those patients in specific subgroups, who continue to have lower event-free survival and who suffer from the long-term effects of treatment. These include those with anaplastic histology, bilateral Wilms, biologically high-risk tumours and those that relapse (Aldrink et al. in J Pediatr Surg 54(3):390–397, 2019). The major advances that have already been made in risk assessment and tailoring the chemotherapy/radiotherapy to achieve maximum advantage with minimum toxicity and long-term morbidity have been predicated on safe and complete resection and staging of the tumour. There are, however, still surgical challenges faced with respect to resection of ‘complex’ tumours; thus, surgeons need to understand their role and advance their expertise in the overall treatment of children with Wilms tumour. These include very large tumours not responding to chemotherapy, ruptured tumours, tumours with intravascular invasion into the inferior vena cava (± 10%), heart and hepatic veins (± 4%) and Wilms tumours in horseshoe kidneys (< 1%) (Kieran and Ehrlich in Urol Oncol https://doi.org/10.1016/j.urolonc.2015.05.029, 2015). This review describes surgical strategies and techniques used in these situations, gleaned from the authors’ experience in the surgical management of over 300 children with Wilms tumours in our centres over the last 30 years.
... The patient may require segmental IVC resection and the prognosis is poor. 2 Wilms tumour is the most common renal tumour in children and is associated with IVC invasion in 4% -8% of cases. 29 Although US can show vascular extension, CT and MR imaging are better for evaluation of metastatic disease. Recognition of IVC involvement is important because it upstages the tumour from I to II and stage II tumour may necessitate neoadjuvant chemotherapy or radiation therapy. ...
The inferior vena cava (IVC) is an uncommon site for primary pathologies and secondary involvement is also infrequent, but involvement of the IVC can often drastically change management. It is therefore important to be cognizant of IVC pathologies. This review discussed common and rare neoplastic and non-neoplastic pathologies of the IVC as well as pathology mimics. Primary and secondary neoplasms can lead to tumour extension or bland thrombus formation and it is often important to distinguish between these two entities. It is also important to be aware of pseudo-lesions for accurate diagnosis. Inferior vena cava filter placement and endovascular treatment of the aorta are commonly performed procedures that can be associated with devastating complications, which are luckily infrequent. The calibre of the IVC also has its own clinical significance. Inferior vena cava pathologies, although rare, have a dramatic impact on the patient’s outcome and knowledge of these pathologies is prudent.
Contribution
Understand the principles of IVC imaging, the common as well as the rare primary and secondary IVC tumours, differentiate between tumour thrombus and bland thrombus, and recognise IVC lesion mimics and life-threatening pathologies involving the IVC.
... Imaging is also critical to evaluate the local extent of the tumor, understand the pertinent surgical anatomy, and rule out a synchronous contralateral tumor or metastatic disease, all of which can significantly impact management [3]. Tumors may be deemed unresectable if thrombus extends above the hepatic veins or tumor extensively involves adjacent organs and their associated vasculature [15,16]. Findings suggestive of rupture include fat stranding around the mass, a poorly circumscribed mass, extracapsular retroperitoneal fluid, and pleural effusion, with ascites beyond the cul-desac [17]. ...
Purpose of Review
The treatment of pediatric renal tumors is nuanced and complex. This review highlights these nuances and aims to prepare the surgeon for treating these complex patients.
Recent Findings
Cooperative group study has improved survival for several pediatric renal tumors significantly, namely, Wilms tumor and clear cell sarcoma. There are several more rare tumors however, which have not achieved the same level of success and still require more study to find the optimal treatment regimen to achieve excellent overall survival. These tumors include rhabdoid tumor and renal medullary carcinoma. Several COG Wilms tumor protocols have recently closed and new ones are set to release soon. It is anticipated that these studies will continue to shift focus to minimizing adverse events/late effects by potentially eliminating or reducing chemotherapeutic exposures while maintaining excellent overall survival. Specifically, new discovery of molecular markers in Wilms tumor will play a significant role with respect to risk stratification. Already, loss of heterozygosity at both 1p and 16q prompts treatment intensification as they are associated with decreased survival. However, gain of 1q, independent of 1p/16q mutations, seems to be more common and even more tightly associated with poor outcomes, which will likely be a key factor involved with adjuvant therapy considerations.
Summary
New treatment protocols for Wilms tumor are forthcoming and will include more molecular markers for risk stratification. Other COG studies on more rare renal tumors are underway to further improve survival for patients with these malignancies.
... CT scans have been reported to establish cavoatrial thrombus precisely. 27 Radiation exposure is a concern about CT. Nonetheless, a CT scan is a rapid procedure, supplies continuous imaging of the abdomen and chest, with perfect chest detail. ...
Wilms tumor (WT) is an embryonal tumor of the kidneys. It is associated with many oncogenic genetic aberrations and congenital anomalies. Owing to worldwide clinical research and optimized patient care, curative therapy can be obtained in 90% of diagnosed children with WT. The decision of treatment mainly depends on stage, age, histological type, and genetic markers. Except for WT; congenital mesoblastic nephroma, clear cell sarcoma, malignant rhabdoid tumor, and renal cell carcinoma constitute 5% of kidney tumors. Herein, WT and other tumors of the kidney will be emphasized.
... US can differentiate solid from cystic or necrotic areas, demonstrate if hemorrhage or calcification is present, and determine whether the tumor involves the renal vein or IVC or extends into the heart. Once an US confirms the presence of a tumor, CT or MRI can better assess the size, extent, involvement of adjacent structures, and spread, and are particularly useful for Wilms tumor staging [225][226][227]. Although CT and MRI are relatively equivalent in assessing the primary kidney mass, CT is the modality of choice to assess for lung metastases. ...
The care of children with diseases of the kidney and urinary tract frequently involves the use of a variety of imaging modalities, both for diagnostic and treatment purposes. This chapter will provide an overview of the radiologic studies and interventions often used in pediatric nephrology, including radiography, excretory urography, contrast fluoroscopy, ultrasonography, computed tomography, magnetic resonance imaging, nuclear scintigraphy, and interventional radiology techniques.KeywordsKidney imagingUrinary tract imagingUltrasoundMagnetic resonance imagingNuclear medicineComputed tomographyInterventional radiologyContrast-enhanced ultrasound
... This could be due to our lower study population size; however, unique genetic contributions could also be a factor, thus raising questions about the need for routine tumour genetic profiling in our population to understand our situation better. CT is associated with a good detection rate for tumour thrombus, 13 Tumour thrombus was seen in 11.8% in our study. A study by Olukayode et al. found that both tumour thrombus and the presence of lymph node metastases were seen in 17% and 50%, respectively, while the former was close to our findings and the latter was two times higher than ours. ...
Objectives:
To review the Computed Tomography( CT )features of pediatric oncological patients with abdominal and pelvic tumours and correlate these findings with their histopathological diagnosis.
Design:
This was a retrospective cross-sectional facility-based study.
Setting:
This study was conducted in the Pediatric Oncology Unit and Radiology Department of the Korle Bu Teaching Hospital.
Participants:
Fifty-six pediatric oncology patients with contrast-enhanced abdominal and pelvic CT scans.
Data collection:
The abdominal and pelvic CT scans findings, patient biodata, and histopathology reports of oncology patients over four years were reviewed.
Statistical analysis:
Simple descriptive statistics using frequency distribution, percentages, means, and standard deviation were used to describe the various variables and presented tables.
Results:
The four commonest tumours were nephroblastoma, neuroblastoma, lymphoma, and hepatoblastoma. The mean age at diagnosis was 4.8 years, with a slightly higher male predominance. The majority of the tumours were extremely large at presentation. Overall, the CT - histopathology concordance was 79.2%.
Conclusion:
Abdominal and pelvic CT scans play an important role in the diagnostic workup of pediatric malignancies by ensuring early and accurate diagnosis of these tumours.
Funding:
None declared.
... A report from Children Oncology Group recommended that computed tomography (CT) was accurate to diagnose tumor thrombus and that additional Doppler evaluation was not needed. 11 Magnetic resonance imaging has been reported to be more reliable than CECT for the evaluation of IVC thrombus and is not operator dependent when compared with ultrasonography. 12 However, the magnetic resonance imaging often requires general anesthesia and is unsuitable for evaluation of chest metastases. ...
Aim:
The aim of our study is to present our experience in the management and outcome of Wilms tumor with intracaval thrombus.
Materials and methods:
All children with Wilms tumor with intracaval thrombus who presented to us from July 2000 to December 2017 were reviewed retrospectively. We evaluated the tumor stage, management, and outcomes in these patients.
Results:
Thirty-four patients were included in the study. The median age of presentation was 48 months (11 to 84 mo). Preoperative chemotherapy was given in 32 (94%), with a median duration of 8 weeks. Intracaval thrombus completely resolved in 9 (26%) children after neoadjuvant chemotherapy. Surgical intervention for residual inferior vena cava (IVC) thrombus was performed in 32 patients. The median follow-up was 30 months (5 to 150 mo). At the last follow-up, 24 patients (70%) were alive and disease free. The 5-year overall survival (OS) and event-free survival were 67% (95% confidence interval, 50% to 84%) and 59% (95% confidence interval, 42% to 76%). The OS in children with nonmetastatic disease (94%) was significantly higher than those with metastases (29%; P<0.01). The OS in children with complete resolution of IVC thrombus (100%) was significantly higher than those with persistent thrombus (48%; P=0.025). Analysis of survival outcomes in children with nonmetastatic disease (stage III) revealed no significant difference on comparison with cohort with stage III disease with absence of IVC thrombus. The P-value was 0.224 and 0.53 for 5-year OS and event-free survival, respectively.
Conclusion:
The management of Wilms tumor can be complicated by the presence of caval thrombus. Patients with metastasis have a significantly poor outcome. Patients in whom, there is complete resolution of intracaval thrombus on neoadjuvant chemotherapy have a significantly higher OS.
... Regarding the vascular invasion in the renal vein, 4 out of the 11 histopathological cases were detected by ultrasonography, while computed tomography revealed 5 cases. In their study, Khanna et al. report a lower sensitivity for the detection of thrombi on ultrasound of 70% compared to 84.6% on CT scan [16,17]. However, intraoperative IVC and/or renal vein palpation is essential in order to avoid transecting an unidentified thrombus [9]. ...
Background:
Wilms' tumour or nephroblastoma is the most common renal malignancy encountered in the paediatric population. Imaging findings are of great importance to the surgeon, the oncologist and the radiologist in the diagnosis and the staging and surveillance of this tumour.
Material and methods:
This study was carried out as a 10-year retrospective study of patients who were diagnosed with Wilms' tumour.
Results:
The study included 12 boys and 11 girls. Ultrasound and computed tomography were performed in all cases. Ultrasonography was found to be superior to the CT examination when approximating the antero-posterior and transverse diameters; the computer-tomographic examination is cited as superior for estimating the invasion of nephroblastomas.
Conclusions:
Ultrasound has been shown to be effective in detecting the rupture of the renal capsule, tumour calcifications and invasion of the renal vein, pelvis and ureter. However, ultrasound cannot replace CT in the detection of lymphadenopathy and the invasion of adjacent organs.
... Contrast MRI (or CT) and ultrasound examinations will need to assess extension of the tumor into the renal vein and vena cava. Echocardiography is warranted to assess heart function and the venous extension of a tumor thrombus into the atrium (31)(32)(33). ...
Significant progress has been made in the management of Wilms tumor (WT) in recent years, mostly as a result of collaborative efforts and the implementation of protocol-driven, multimodal therapy. This article offers a comprehensive overview of current multidisciplinary treatment strategies for WT, whilst also addressing recent technical innovations including nephron-sparing surgery (NSS) and minimally invasive approaches. In addition, surgical concepts for the treatment of metastatic disease, advances in tumor imaging technology and potentially prognostic biomarkers will be discussed. Current evidence suggests that, in experienced hands and selected cases, laparoscopic radical nephrectomy and laparoscopic-assisted partial nephrectomy for WT may offer the same outcome as the traditional open approach. While NSS is the standard procedure for bilateral WT, NSS has evolved as an alternative technique in patients with smaller unilateral WT and in cases with imminent renal failure. Metastatic disease of the lung or liver that is associated with WT is preferably treated with a three-drug chemotherapy and local radiation therapy. However, surgical sampling of lung nodules may be advisable in persistent nodules before whole lung irradiation is commenced. Several tumor markers such as loss of heterozygosity of chromosomes 1p/16q, 11p15 and gain of function at 1q are associated with an increased risk of recurrence or a decreased risk of overall survival in patients with WT. In summary, complete resection with tumor-free margins remains the primary surgical aim in WT, while NSS and minimally invasive approaches are only suitable in a subset of patients with smaller WT and low-risk disease. In the future, advances in tumor imaging technology may assist the surgeon in defining surgical resection margins and additional biomarkers may emerge as targets for development of new diagnostic tests and potential therapies.
... To enable appropriate surgical planning, radiological preoperative detection of the tumour thrombus and its extent is essential. Our study has shown 15% of tumour thrombi were not seen on cross-sectional imaging, which is similar to the literature [30,31]. In cases where presurgical uncertainty persists, it is prudent to perform a pre-operative or an intra-operative doppler US to define the extent of thrombus 'on-table' [32]. ...
Purpose
to review surgical management, tumour stage and clinical outcomes in children with intravascular extension of Wilms tumour (WT) registered in a national clinical study (2012-19).
Methods
WTs with presence/suspicion of tumour thrombus in the renal vein (RV) or beyond on radiology, surgery or pathology case report forms were identified. Only cases where thrombus was confirmed by surgeon and/or reference pathologist were included. Surgical management, disease stage, overall (OS) and event free survival (EFS) were investigated.
Results
69/583 (11.8%) patients met the inclusion criteria. Forty-six (67%) had abdominal stage III due to thrombus-related reasons: 11 had macroscopically incomplete resection, including 8 cases where cavotomy was not performed; 20 had piecemeal complete resection of thrombus; 15 had microscopically positive resection margins at the RV. 66% of tumour thrombi contained viable tumour. There were eight relapses and five deaths. EFS, but not OS, was significantly associated with completeness of surgical resection (P<0.05). OS and EFS were also significantly associated with histological risk group (P<0.05) but not with viability of tumour thrombus (P=0.19; P=0.59).
Conclusions
WTs with intravascular extension have a high risk of local stage III due to thrombus-related reasons. Controlled complete removal of the thrombus should be the aim of surgery.
... Contraindications to upfront surgery include tumor extension to contiguous structures; solitary kidney; extension of tumor thrombus above the hepatic veins; unacceptable anesthesia risk due to pulmonary metastases or very large abdominal tumors; and/or risk for significant morbidity or mortality, gross tumor spill, residual tumor, or long-term renal failure. 80 Metastases are not typically a contradiction to surgery. ...
The NCCN Guidelines for Wilms Tumor focus on the screening, diagnosis, staging, treatment, and management of Wilms tumor (WT, also known as nephroblastoma). WT is the most common primary renal tumor in children. Five-year survival is more than 90% for children with all stages of favorable histology WT who receive appropriate treatment. All patients with WT should be managed by a multidisciplinary team with experience in managing renal tumors; consulting a pediatric oncologist is strongly encouraged. Treatment of WT includes surgery, neoadjuvant or adjuvant chemotherapy, and radiation therapy (RT) if needed. Careful use of available therapies is necessary to maximize cure and minimize long-term toxicities. This article discusses the NCCN Guidelines recommendations for favorable histology WT.
... Nephroblastoma, also known as Wilms' tumor (WT), is the most common malignant solid tumor of the urinary system in childhood. At present, the diagnosis of nephroblastoma is mainly based on the clinical manifestations of children combined with ultrasound, intravenous urography or computed tomography (Khanna et al., 2012;Arnold et al., 2014;Salvatorelli et al., 2015). Surgery and chemotherapy are the main therapeutic methods. ...
This study aimed to probe carcinogenic genes and pathways associated with Wilms' tumor (WT) onset and malignancy progression. After screening, three datasets acquired from the Gene Expression Omnibus database were analyzed. Differentially expressed genes (DEGs) were identified and GO functional enrichment, KEGG pathway enrichment and protein–protein interaction (PPI) were analyzed. The DEGs with top fold change values or top protein interaction scores were used to analyze overall survival based on the TARGET WT dataset. Together, 866 up-regulated genes in GDS1791, 585 up-regulated genes in GDS2010, and 277 down-regulated genes in GDS4802 were found, from which 46 key DEGs were selected for further analysis. In the PPI network, hub positions included COL5A1, COL4A1, ARPP21, SPARCL1, CD86, LY96 and PPP1R12B. The top DEGs (ARPP21, SYNPO, PRRC2B, PPP1R12B, EFCAB2 and LY96) were selected for survival analysis, and they consistently showed a significantly positive correlation with poor survival. Together, five key carcinogenic genes (SYNPO, PRRC2B, PPP1R12B, EFCAB2 and LY96) were highly associated with WT onset and patient survival. These risk genes, interaction networks and enrichments should improve our understanding of the complex molecular mechanisms in WT development and help clinical applications.
... The surgical stages of our cases were compared to National Wilms' Tumor study (NWTS): stage I patients comprised 42% of all patients in NWTS3, while in this study it was found in 32.7% of patients in the first decade and 14.3% in the second decade. Also, the rate of the bilateral tumor was 5 times higher in the second decade (4)(5)(6). Thus in Iran, sick children were submitted to specialized centers with much delay. ...
Background: Wilms’ tumor (nephroblastoma) is the major renal cancer in children. Objectives: The aim of this study was to assess the individuality of Wilms’ tumor and the consequences of management attained in our referral subspecialty center. Methods: In this study, we composed the data of children with Wilms’ tumor in 2 decades; 55 cases between 1992 and 2002 and 49 patients between 2006 and 2016 were diagnosed with Wilms’ tumor. Demographic characters, a form of presentation, tumor stage, related underlying disease, histopathology consequences, type of management, and the survival rates were assessed. Results: In the first decade, 24 patients were females and 31 were males (M/F = 1.2); in the other groups, 30 were females and 19 were males (M/F = 0.61). The mean age was 45.2 months at the time of diagnosis for the first group and the mean age was 36 months for the other group. In the first decade, the surgical stage after the operation was as follows: stage I (32.7%), stage II (16.36%), stage III (38.1%), stage IV (9%), and stage V (1.8%) who did not operate. In second decade, 49 patients were as follows: stage I (14.3%), stage II (40.8%), stage III (24.5%), stage IV (10.2%), and stage V (10.2%). In 54.5% of the first group, histology was favorable, and in 43.6% of the first group, histology was unfavorable; in the second group, 95.4% were the favorable type. The patients were managed based on protocols of the National Wilms’ Tumor Study. In the first decade, relapse-free was 71% and 4-year survival rates were estimated at 86%, and in the second decade, pulmonary metastasis was observed at 28.6%, liver metastasis in 2.3%, recurrence in 5%, and 4-year survival rates were estimated at 90%. Conclusions: This study demonstrated development in the management of children with Wilms’ tumor in recent 20 years, with comparable relapse-free and survival rates to the National Wilms’ Tumor study. But with more adjustment in treatment protocols, the superior outcome will be attainable.
... The probability of secondary malignancies increases with increasing radiation exposure and has a cumulative effect. [14] . Contrast-enhanced MRI was also used in the diagnosis and characterization of renal tumors [15,16] . ...
Background : Contrast enhanced ultrasound (CEUS) has been actively used in the detection of lesions in many organs especially in kidney and liver, but there is no report in evaluation of preoperative chemotherapy for Wilms tumor in children.
Methods: 8 children with Wilms tumor were enrolled in this study. All patients accepted preoperative chemotherapy for 4-8 weeks. Each child accepted CEUS examination for 3 times. The image files and the data were analyzed through software.
Results: The group included 8 cases with tumor volume from 155.71 to 1624.16 cm³. 6 patients accepted preoperative chemotherapy for 8 weeks before surgery, 2 cases underwent preoperative chemotherapy for 4 weeks. Each child accepted CEUS examination for 3 times and no one showed discomfort to the SonoVue contrast agent. By the comparison from the 3 times CEUS, tumor volume in most of the children was significantly reduced, and the blood perfusion intensity in the tumor was prominently weakened. The results of linear regression showed that the changes of PI between the first and second CEUS examinations and between the second and third CEUS examinations had correlation with the reduction volume of Wilms tumor.
Conclusions: It is the first time to apply quantitative analysis of CEUS in evaluation of preoperative chemotherapy for Wilms tumor in children. CEUS is a safe examination in children. CEUS videos could show clearly the changes of tumor perfusion during preoperative chemotherapy. PI can precisely reflect the degree of sensitivity of tumor to chemotherapy in early stage of preoperative chemotherapy.
... 4 Computerized tomography helps in assessing the origin of the tumor; bilateral renal involvement; lymph node involvement; and invasion into the renal vessels, Inferior vena cava or right atrium. 5 The crescent sign, the embedded kidney sign, the beak sign and the renal arteries feeding sign are the specific findings of computed tomography which help in distinguishing renal tumours from non-renal origin tumors. 6 CT can also accurately identify vascular invasion that will impact surgical approach along with identification of the preoperative parameters associated with increased risk of intraoperative Wilms' tumor spill. ...
CT can also accurately identify vascular invasion that will impact surgical approach along with identification of the preoperative parameters associated with increased risk of intraoperative Wilms’ tumor spill. Objectives: To determine positive predictive value of CT scan in diagnosing wilm’s tumour, taking histopathology as gold standard. Study Design: Descriptive, cross sectional study. Setting: Department of Urology & Renal Transplantation Centre, Bahawal Vitoria Hospital, Bahawalpur. Period: From July 2017 to June 2018. Materials & Methods: A total of 81 patients with suspected wilm’s tumour on ultrasonography of age 1-12 years of either gender were included. Patients with recurrent tumour and undergoing pre-op chemotherapy were excluded. All the patients were then underwent CT scan and looked for presence or absence of wilm’s tumour. The results were compared with histopathology. Results: Mean age was 5.23 ± 3.28 years. Majority of the patients 56 (69.14%) were between 1 to 6 years of age. Out of these 81 patients, 61 (75.31%) were female and 20 (24.69%) were males with female to male ratio of 2.9:1. CT scan supported the diagnosis of wilm’s tumour in all 46 patients. Histopathology confirmed wilm’s tumour in 41 (true positive) cases where as 05 (False Positive) had no wilm’s tumour on histopathology. Positive predictive value of CT scan in diagnosing wilm’s tumour, taking histopathology as gold standard was 89.13%. Conclusion: This study concluded that positive predictive value of CT scan in diagnosing wilm’s tumour is quite high.
... Ultrasonography has an accuracy of 60-100% in the diagnosis of tumor thrombus and can evaluate the degree of adhesions between the thrombus and vascular wall by venous blood flow. However, Khanna et al. reports that in the primary nephrectomy group, sensitivity of Doppler sonography for the detection of cavoatrial thrombus was 70.0%, lower than CT 84.6% [6]. In this study, one case with renal vein thrombus was found by enhanced CT examination, but the thrombus was found by ultrasound examination. ...
Background
Wilms tumor tends to grow into vena cava, even invade atrium, which increased operating difficulty and frequency of surgical complications.
Methods
Forty-two patients of Wilms tumor with intravenous thrombus were retrospective studied. The diagnosis and therapy were discussed according to the medical records and interrelated literatures.
Results
Forty-two children with thrombus were diagnosed by computed tomography and 41 cases by ultrasound simultaneously. 36 children had received preoperative chemotherapy. Surgical resection was performed in all patients. Cardiopulmonary bypass was used for the removal of the intra-atrial thrombus in 5 patients. There were no surgical complications occurred. The patients received chemotherapy and radiotherapy according to clinical staging by National Wilms’ Tumor Study (NWTS)-4 or NWTS-5. 34 patients were successfully followed up, 32 patients survive at present, including one who has been followed up more than 20 years since operation.
Conclusion
Standardized sequential treatment, including preoperative chemotherapy and radiotherapy, nephrectomy combining resection of thrombus, postoperative adjuvant therapy, is the mainstay of treatment of Wilms tumor with intravenous thrombus.
... While intravascular thrombus is common (20-35%), IVC involvement is seen in only 4-10% [12] (Fig. 10). In general, CT is sensitive and specific for pre-operative identification of IVC and right atrial tumor thrombus [13], but ultrasound may be a useful problem-solving adjunct for detecting intravenous extension when CT is equivocal [12]. ...
The inferior vena cava (IVC) is the largest venous conduit below the diaphragm. Although this structure is often overlooked both clinically and radiographically, it can be involved in many different pathologic processes. A thorough understanding of the IVC will assist the radiologist in recognizing anatomic variants, identifying abnormalities, and providing accurate differential diagnoses. In this comprehensive pictorial review of the IVC, we depict embryology behind anatomic variants, present a wide range of pathology with a focus on diagnostic imaging, and describe relevant endovascular interventions.
... Although preoperative chemotherapy for tumor thrombus extending above the hepatic vein is a commonly accepted treatment, there has not been much research on the choice and duration of anticoagulant therapy in these cases [60,62]. ...
: Venous thromboembolism (VTE) result in significant morbidity and mortality in children with cancer. The cause of VTE in children with cancer is multifactorial and includes genetic predisposition (thrombophilia), disease-related factors, and treatment-related factors including use of central venous catheter (CVC), surgery, and chemotherapy. This review aims to examine current knowledge regarding the incidence, risk factors, clinical manifestation, evaluation, prevention, and management of thromboembolic events in children with cancer.
... Thus, lymph node sampling or dissection in a patient with a venous anomaly might be adjusted accordingly [7]. WT involves IVC invasion in 4-8% of cases [19], and caval extension of WT has been an important surgical challenge. Although tumor thrombus of renal vein or IVC was not found in the present case, extension of renal cell carcinoma into duplications of IVC and the retroaortic renal veins has been reported [18,[20][21][22]. ...
Background:
Wilms tumor is the most common renal tumor of childhood. Duplication of the inferior vena cava is an uncommon anomaly. In the present study, we present a case of Wilms tumor with the inferior vena cava duplication, which has not been reported previously.
Case presentation:
A 14-month-old female presented with an enlarging abdominal mass. Computed tomography imaging demonstrated a large mass in the right kidney, duplication of the inferior vena cava below the renal veins and compression of the right inferior vena cava caused by the enormous mass. A right radical nephrectomy was performed. Final pathology was consistent with Wilms tumor. Postoperative adjuvant chemotherapy was executed. Computed tomography imaging at 3 months postoperatively showed the right inferior vena cava played a dominant role and the left inferior vena cava was not detected clearly. During the follow-up of 18 months, no local recurrence or metastasis has been observed.
Conclusion:
It is important to recognize the case of Wilms tumor with the inferior vena cava duplication to avoid injury of retroperitoneal venous anomalies and life-threatening hemorrhage during surgery through preoperative computed tomography.
... 34 Wilms tumor is the most common renal tumor in children and involves IVC invasion in 4% to 8% of cases. 35 Tumor thrombus is a rare complication of primary lung carcinoma. 3 Adrenal gland is one of the common sites of metastasis from primary lung cancer. ...
Inferior vena cava (IVC) tumor thrombus in renal cell carcinoma is a rare entity that suggests heightened biologic behavior and a surgical challenge during the course of treatment. Tumor thrombus can extend from the renal vein to the right atrium. This cephalad extension is classified by four different levels. These levels determine which surgical approach is used, whether a thoracoabdominal incision is needed, and whether a patient needs to be placed in circulatory arrest. Complete surgical resection of the tumor is potentially the only curative treatment, although it supposes a challenge because of operative difficulty and the potential for massive bleeding or tumor pulmonary thromboembolism. IVC tumor thrombus presents with a few differentials that need to be assessed, including bland thrombus, primary IVC leiomyosarcoma, hepatocellular carcinoma, adrenal cortical carcinoma, primary lung carcinoma, and Wilms tumor. The importance of diagnosing IVC tumor thrombus secondary to renal cell carcinoma is demonstrated as well as a sonographic protocol for assessing IVC tumor thrombus.
... Ameliyat öncesinde bilgisayarlı tomografi veya Doppler ultrasonografi ile tümör trombüsü araştırılabilir. Bir COG çalışmasında trombüsü göstermede iki yöntemin de eşit etkinliğe sahip olduğu gösterilmiştir (14) . Ancak ameliyat sırasında renal ven, trombüs varlığı açısından elle değerlendirilmelidir (2) . ...
Cancer is the second most common cause of death in children aged 1–14 years, surpassed only by accidents. Leukemia is the most common childhood cancer, followed by central nervous system (CNS) cancer, lymphoma, neuroblastoma, nephroblastoma, and other nonepithelial renal tumors, malignant bone tumors, and rhabdomyosarcoma. The overall cancer incidence rate in children and adolescents has been increasing since 1975 for reasons that remain unclear, but, on the other side, death rates are in continuous decline, starting from 6.3/100000 in children and 7.1/100000 in adolescents in 1970 to 2.0/100000 and 2.9/100000, respectively, in 2018. The appropriate utilization of radiology resources is an important topic in medicine because it exposes children to unnecessary and damaging radiation, especially in children. Nowadays we have diagnostic imaging techniques that do not involve the use of ionizing radiation such as ultrasound (US) and magnetic resonance imaging (MRI) which are always preferred in children. Compared to CT, MRI provides additional information, but has several limitations such as the long acquisition time (30–45 min) and the loud noise emitted by the equipment. These two factors are very negative for a small child who cannot stay still for a long time and cries because of the noise. For these reasons, there is a need for counseling, sedation or general anesthesia.
Wilms’ tumor is the most common pediatric kidney cancer worldwide. Ninety percent of unilateral Wilms’ tumor cases occur in otherwise healthy patients and are regarded as sporadic, but 10% are associated with congenital anomalies or a tumor predisposition syndrome. Five to seven percent of Wilms’ tumor cases are found to be bilateral, involving both kidneys. Wilms’ tumor most often presents as an asymptomatic abdominal mass in children between 2 and 4 years old. Contrasted dual-phase CT scan of the abdomen and pelvis provides excellent anatomic evaluation of pediatric renal masses. Wilms tumor is typically chemosensitive, and either up-front radical nephroureterectomy or neoadjuvant chemotherapy is employed at diagnosis depending on local resources and protocol-driven management directives. The standard of care operation for unilateral Wilms’ tumor is radical nephroureterectomy with lymph node sampling, while bilateral nephron-sparing surgery is advocated for bilateral Wilms’ tumor. Difficult surgical scenarios including venous thrombectomy, nephron-sparing surgery, bilateral Wilms’ tumor, or resection of Wilms tumor in the setting of nephroblastomatosis benefit from experienced surgical teams. Increasing understanding of the molecular genetic etiology of non-Wilms’ tumor pediatric renal malignancies including renal cell carcinoma, rhabdoid tumor, clear cell sarcoma, congenital mesoblastic nephroma, multilocular cystic nephroma, and renal medullary carcinoma may lay the groundwork for new therapies in the future.
Malignant renal tumors are rare in children, and Wilms tumors (WTs) are the most common subtype. Imaging plays an essential role in the diagnosis, staging, and follow‐up of these patients. Initial workup for staging is mainly performed by cross‐sectional imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). Imaging approach within the two core international groups, the Children's Oncology Group (COG, North America) and the International Society of Pediatric Oncology ‐ Renal Tumor Study Group (SIOP‐RTSG, Europe), differs. Whereas abdominal ultrasound (US) is used for the initial diagnosis of a suspected pediatric renal tumor globally, COG protocols support the use of CT or MRI for locoregional staging, contrary to the preference for MRI over CT for abdominopelvic evaluation within the SIOP‐RTSG. The purpose of this manuscript is to summarize current imaging approaches, highlighting differences and similarities within these core international groups, while focusing on future innovative efforts and collaboration within the HARMONICA initiative.
Malignant renal tumors account for approximately 6% of pediatric malignancies, with Wilms tumor (WT) representing approximately 90% of pediatric renal tumors. This paper provides consensus-based imaging guidelines for the initial evaluation of a child with suspected WT and follow-up during and after therapy co-developed by the Children's Oncology Group (COG) Diagnostic Imaging and Society for Pediatric Radiology (SPR) oncology committees. The guidelines for Wilms Tumor Imaging in the Society of International Pediatric Oncology (SIOP) are briefly discussed to highlight some of the differences in imaging approach.
Wilms’ tumor (WT) has the ability to extend through the renal vein to the inferior vena cava (IVC) and even up to the right atrium. The incidence of intravascular thrombus is documented to range between 4 and 10% in various series for inferior vena cava and 1% for atrial extension.The oncological outcome is not influenced by this complication; however, thrombus occurrence represents a remarkable difficult factor for surgical procedures, hence increasing the morbidity.Intravascular thrombus is usually asymptomatic and is detected preoperatively on ultrasound, computerized tomography (CT) scan, and/or magnetic resonance imaging (MRI). Detailed clinical examination and history still have an important role in the era of advanced imaging. Ascites, hepatomegaly, and varicocele in left-sided tumors are subtle clinical signs indicating a more detailed radiological examination. MRI is the best method of imaging a suspected tumor thrombus. However, ultrasound Doppler and CT angiography scans, along with an echocardiogram, are the commonly used techniques to delineate the thrombus, as they also give excellent results.The COG, SIOP, and other WT study groups all recommend preoperative chemotherapy for downsizing the tumor as well as the thrombus. There has been significant reduction in complications in patients treated with three-drug neoadjuvant chemotherapy for at least 6 weeks, especially in those extending above the hepatic veins.The operative approach to these patients depends upon the extent of the thrombus and may require a multidisciplinary team including cardio-thoracic surgeons and expert anesthesiologists.The learning point in this chapter would include the radiological algorithm for diagnosis and guidelines for the surgical approaches and strategies. The role of cardiothoracic surgery and cardiopulmonary bypaas (CPB) and its indications would be discussed in detail. The surgical and oncological outcomes in intravascular thrombus would also be reviewed.KeywordsIntravascular thrombosisCavotomyCavectomyCardiopulmonary bypassMultidisciplinary approach
Imaging has a critical role in managing Wilms’ tumor, from the initial disease diagnosis and staging to the posttreatment surveillance. This chapter discusses the various imaging modalities available, their relative advantages and disadvantages, and the current role of each imaging modality according to the SIOP and COG guidelines so that a rational imaging approach can be followed for the evaluation of WT. In the final section, the role of imaging and methods of surveillance in posttreatment cases of Wilms’ tumor or children with known tumor predisposition syndromes will be discussed.KeywordsWilms’ tumorImagingStagingComputed tomographyUltrasoundMagnetic resonance imagingSurveillance
Pediatric cancer patients have improved outcomes over the past several decades leading to a greater number of survivors living well into adulthood. Owing to their increased longevity, adult care providers are encountering childhood cancer survivors with greater frequency in their clinics and hospitals. Childhood cancer treatments are associated with varied and significant systemic complications that either persist or develop well into adulthood, including secondary malignancies, cardiomyopathies, and adhesive disease that can complicate even the simplest operation. This article reviews four of the most common solid abdominal tumors in the pediatric population and the long-term sequelae of their respective treatment regimens.
Introduction
Inferior vena cava (IVC) thrombus is an uncommon and challenging complication of abdominal malignancies in the pediatric population, which significantly influences the treatment options and clinical outcomes in this population.
Methods
In this review, we present the presentation, treatments, interventions, and outcomes with this clinically and technically challenging oncological finding from a free-standing children's hospital from 2006 to 2017.
Results
Fourteen patients with IVC thrombus were identified as having an associated abdominal malignancy. The abdominal malignancies consisted of eight Wilms tumors (63% stage III and 37% stage IV), and one spindle cell sarcoma, neuroblastoma (stage III), kidney clear cell sarcoma (stage III), sclerosing epithelioid fibrosarcoma, hepatoblastoma-epithelial (stage IV), and hepatic embryonal sarcoma (stage IV). 50% of patients were male, 71% White, 29% Black, 7% Hispanic; mean age at diagnosis was 4.09 (SD 2.43) years. CT imaging identified IVC tumor thrombus for 79% of patients, US abdomen complete recorded 14%, and MRI lumbar 7%. 3Out of 14 patients, 13 patients were taken to the operating room with 12 patients undergoing concurrent tumor resection and IVC thrombectomy. Of the remaining patients, one had IVC thrombectomy via femoral cutdown by interventional radiology, and one was noted to have resolution of IVC thrombus with neoadjuvant chemotherapy. Of patients who underwent resection, one required IVC ligation, and one patient required IVC interposition vein graft reconstruction using a right IJ conduit. 60% of patients undergoing thrombectomy received neoadjuvant chemotherapy. Mean time from the diagnosis of IVC tumor thrombus to surgical thrombectomy was 46 (SD 44) days. No operative mortalities were reported. There were five major complications (hemothorax, pulmonary embolisms, seroma, and sepsis) and two minor complications (pneumonia and UTI). With exclusion of patient who underwent IVC ligation, no patients developed signs of IVC compression or recurrent thrombosis after thrombectomy.
Conclusions
IVC tumor thrombus can significantly alter the clinical treatment, surgical options, and outcomes of malignant abdominal tumors. Treatment of IVC tumor thrombus included adjuvant chemotherapy, segmental IVC resection with or without reconstruction, thrombectomy with intimal stripping, or resection of the thrombus with part of the IVC wall. Evidence for standard treatment practices for IVC tumor thrombus in the setting of abdominal malignancy is lacking due to the rarity of this finding and the varied clinical presentations.
Abnormalities of the neck vessels and peripheral and retroperitoneal vasculature are relatively rare in the pediatric population. Nonetheless, increasing numbers of hospitalized children and those with chronic conditions routinely require evaluation of these vessels prior to diagnostic procedures and following therapeutic intervention. In this chapter, the utility of ultrasound in the diagnosis and management of pediatric vascular disorders is reviewed, as well as appropriate transducer selection, patient positioning, and imaging techniques. Pertinent development and anatomy of the arteries and veins of the neck, upper and lower extremities, and retroperitoneum are discussed. The ultrasound features of anatomical variants, congenital anomalies, thrombosis, stenosis, aneurysm/pseudoaneurysm, arterial dissection, and arteriovenous fistula as well as management approach are emphasized.
Wilms’ tumor accounts for the majority of renal tumors in children. Rarely, Wilms’ tumor may metastasize to the bone. We present a case of a 15-month-old female who presented with severe abdominal distension and signs of cachexia. Abdominal ultrasonography and radiography of the abdomen both demonstrated a large abdominal mass. Follow-up computed tomography of the abdomen revealed a heterogeneous intra-abdominal mass arising from the left kidney which was surrounded by a thin rim of renal parenchyma. Biopsy of the mass revealed findings consistent with Wilms’ tumor. The patient was 14 months status-post nephrectomy and chemoradiation but returned to the clinic with left facial swelling. Magnetic resonance imaging of the face demonstrated a multilobulated, heterogeneously enhancing solitary mass lesion in the left temple centered in the left zygoma with signs of bone breakdown. Despite its rarity, metastatic Wilms’ tumor to bone should be considered in a child presenting with a new focal mass overlying bony-structures.
The most recent advance in the care of children diagnosed with hepatoblastoma and hepatocellular carcinoma is the Pediatric Hepatic International Tumor Trial, which opened to international enrollment in 2018. It is being conducted as a collaborative effort by the pediatric multicenter trial groups in North America, Europe, and the Far East. This international effort was catalyzed by a new unified global risk stratification system for hepatoblastoma, an international histopathologic consensus classification for pediatric liver tumors, and a revised 2017 collaborative update of the PRE-Treatment EXTent of disease radiographic based staging system.
This article reviews the epidemiology, pathophysiology, clinical presentation, and multimodality management of Wilms tumors and renal cell carcinoma in pediatric and young adults. Key renal Société Internationale d'Oncologie Pédiatrique and Children Oncology Group studies are presented. The article reviews the common staging systems and risk-adapted treatment strategies with particular attention to the surgical management.
Background
Studies describing intravascular involvement in Wilms tumor have focused on illustrating individual institutional experience and the elements of surgical management. Thrombus characteristics like extent, patterns of regression, and correlation with the surgical findings, intraluminal adhesion, and viable tumor in the thrombus, and patency of the inferior vena cava (IVC) have not been systematically described.
Objectives
The aim of this study is to evaluate these thrombus characteristics and explore their impact on the overall outcomes.
Methods
All patients with histologically confirmed Wilms tumors with intravascular thrombus diagnosed in the pediatric oncology unit of Tata Memorial Hospital registered from 2006 to 2019 were included. Data regarding clinical, radiological, and surgical particulars were retrieved from the prospectively maintained institutional database. Specific data for the thrombus included: distal extent before and after neoadjuvant chemotherapy, correlation of extent with the surgical findings, completeness of thrombectomy, the presence of a viable tumor in the thrombus, and the patency of the IVC. Survival analysis was performed utilizing the Kaplan–Meier method on SPSS software version 25.
Results
The study included 43 (9.9%) of the 432 patients with Wilms tumor having intravascular extension. Retrohepatic IVC (33.3%) followed by atrioventricular (26%) formed the frequent levels of thrombus with maximum regression occurring after chemotherapy in the latter (Summary figure). The overall concordance rate between computed tomography (CT) scan and surgical findings for the presence of thrombus was 86% and 4 patients had the thrombus limited to a lower level than the preoperative scan. At a median follow-up of 5-years, the 5-year event-free and overall survival was 81% and 82.2% respectively. Atrioventricular thrombus (p = 0.003) and postoperative patency of IVC (p = 0.02) were significantly associated with inferior survival, while the extent of regression, thrombus fracture, and viability was not significant.
Discussion
The findings of this study bring forth the characteristics of intravascular tumor thrombus affecting the outcomes which can be validated in future prospective studies. Although the ideal method for radiological assessment of the intravascular thrombus is elusive, CT scan provided adequate information for the presence and level of the intravascular thrombus with reasonable accuracy in this study. Study limitations include small sample size, the limited number of events, and lack of multivariate analysis to rule out confounding factors that could influence the observed findings.
Conclusion
Atrioventricular thrombus and occlusion of IVC represent adverse prognostic factors. The extent of regression, fracture, and viability of thrombus did not affect survival in this study.
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Summary fig.. A collage of axial, coronal and sagittal computed tomogram images showing retrohepatic [A and A1], atrial [B and B1], ventricular [C and C1] thrombus.
Imaging has a key role in the assessment of paediatric renal tumours, especially when the initial treatment approach is to proceed to standard chemotherapy without histological confirmation. In Europe, according to the International Society of Paediatric Oncology guidelines, core needle biopsy is not routinely done unless the child is older than 10 years. Between age 6 months and 9 years, the child is treated with a standard regimen of preoperative chemotherapy unless there are concerns about non-Wilms' tumour pathology. Atypical imaging findings could therefore stratify a child into a different treatment protocol, and can prompt the need for pretreatment histology. This review details the latest protocols and techniques used in the assessment of paediatric renal tumours. Important imaging findings are discussed, especially the features that might prompt the need for a pretreatment biopsy. Local radiology practices vary, but both MRI and CT are widely used as routine imaging tests for the assessment of paediatric renal tumours in Europe. Advances in imaging technology and MRI sequences are facilitating the development of new techniques, which might increase the utility of imaging in terms of predicting tumour histology and clinical behaviour. Several of these new imaging techniques are outlined here.
The current positive computed tomography (CT) contrast agents (PCTCAs) including clinical iodides, present high CT density value (CT‐DV). However, they are incapable for the accurate diagnosis of some diseases with high CT‐DV, such as osteosarcoma. Because bones and PCTCAs around osteosarcoma generate similar X‐ray attenuations. Here, an innovative strategy of negative CT contrast agents (NCTCAs) to reduce the CT‐DV of osteosarcoma is proposed, contributing to accurate detection of osteosarcoma. Hollow mesoporous silica nanoparticles, loading ammonia borane molecules and further modified by polyethylene glycol, are synthesized as NCTCAs for the diagnosis of osteosarcoma. The nanocomposites can produce H2 in situ at osteosarcoma areas by responding to the acidic microenvironment of osteosarcoma, resulting in nearly 20 times reduction of CT density in osteosarcoma. This helps form large CT density contrast between bones and osteosarcoma, and successfully achieves accurate diagnosis of osteosarcoma. Meanwhile, The NCTCAs strategy greatly expands the scope of CT application, and provides profound implications for the precise clinical diagnosis, treatment, and prognosis of diseases. A negative computed tomography (CT) contrast agent based on hollow mesoporous silica nanoparticles@ammonia borane@polyethylene glycol nanocomposite can produce H2 in situ at osteosarcoma areas by responding to the acidic microenvironment of osteosarcoma, and prominently reduce the CT density of osteosarcoma, which can form large CT density difference contrast between bones and osteosarcoma, and further realize accurate diagnosis of malignant osteosarcoma.
Treatment of pediatric renal malignancies has seen dramatic advances in recent years. Modifications to surgical approach and the tailoring of chemoradiation protocols have led to increased survival, and now attention is focused on mitigating long-term effects of cancer-related treatment. Wilms tumor comprises the largest subset of pediatric renal tumors and as such will be the major focus of this chapter. The genetics and treatment of Wilms tumor will be reviewed in detail. Additionally, more infrequently encountered pediatric renal malignancies will also be explored.
Wilms᾿ tumor, or renal nephroblastoma, is the commonest malignant renal tumor in children and young adults. Intravascular and intracardiac extension of this tumor is a very rare and challenging clinical entity. The case is reported of a 6-year-old boy diagnosed with nephroblastoma, in whom the tumor involved the inferior vena cava and the right atrium. The successful multimodal surgical management consisted of combined, synchronous surgical resection of both renal and intracardiac tumors. The boy had an uneventful postoperative course and recovery, followed by relapse-free living. Intra-cardiac extension of Wilm’s tumor poses a surgical challenge where the favorable outcome is provided only by the combined and well-coordinated, skilled multidisciplinary care of pediatric surgeons and pediatric cardiac surgeons.
The purpose of our study was to present multidetector computed tomography (MDCT) findings in venous spread of renal cell carcinoma (RCC), to determine the superior extent of tumor thrombus and to compare MDCT findings with surgical report.
The prospective MDCT study was performed on 31 patients diagnosed with RCC with venous spread (19 males and 12 females; age range 39-80 years; mean age 62.6 years). CT scans were obtained by MDCT scanner, in triphasic scanning protocol. All postprocessing techniques were performed by two independent radiologists, and the findings were reported in their consensus. MDCT diagnosis was compared with surgical and pathohistological findings.
Tumor thrombus extension into renal vein only (T3b stage) was found in 13/31 (42%) patients. Involvement of infradiaphragmatic level of inferior vena cava (IVC) (T3c stage) was found in 14/31 (45%) patients and supradiaphragmatic level of IVC (T4b stage) in 4/31 (13%) patients. In 27/31 (87%) patients surgery was performed, while 4/31 (13%) could not undergo surgery. In comparison with surgical report, in 25/27 (93%) operated patients the upper extent of the tumor thrombus was correctly diagnosed by MDCT, and 2/27 (7%) patients were falsely diagnosed.
MDCT represents a fast, relatively inexpensive, and reliable diagnostic method for evaluating the venous spread of RCC as well as the level of its upper extent. Triphasic MDCT is often the only diagnostic method necessary for planning the surgical procedure. Surgery should be performed as soon as possible for MDCT findings to be valid.
Extension of Wilms' tumor through the inferior vena cava into the heart presents a formidable clinical challenge. Excision of such a tumor without provoking emobilization may require cardiopulmonary bypass (CPB). The completeness of excision and the likelihood of tumor embolization during operation guide subsequent radiation therapy (RT) and chemotherapy. To help define these issues, the clinical records of 15 patients enrolled in three National Wilms' Tumor Studies (NWTS) who had intracardiac tumor extension (ICE) were reviewed. The median age at diagnosis was 4 years. One patient had clear cell sarcoma (CCS); the remainder had favorable histologic findings (FH). The clinicopathologic stage was stage II in one patient, stage III in eight patients, and stage IV in six patients. ICE was detected before operation in six patients, during operation in five patients, and after operation in five patients. CPB was used in 10 patients. Eleven patients (73%) had operative complications, with major intraoperative hemorrhage occurring most often (six patients). Complications occurred less often when ICE was recognized before operation (three of six patients) than when it was not (eight of nine patients). Embolization occurred in only two patients. There were no operative deaths. The patient with CCS died. Eleven of 14 patients with FH survived, with an actuarial event-free, 2-year survival rate of 86%. There were no patients in the first NWTS. Of the six patients in the second NWTS (NWTS-2), four died (67%). All nine patients in the third NWTS (NWTS-3) survived, but follow-up was shorter (median 4 years 9 months vs. 2 years 7 months). No particular surgical procedure was associated with an increased death rate. This review suggests (1) Wilms' tumor with ICE presents a formidable surgical undertaking but has a relatively good prognosis. (2) Embolization is an uncommon event in ICE (two patients, 13.3%), allowing a planned operative approach. Echocardiography and ultrasonography provide accurate preoperative diagnosis. And (3) ICE should be suspected in patients with extensive vena cava thrombosis or who have hypotension or heart failure during examination or surgery.
To assess the diagnostic accuracy of colour flow Doppler ultrasound in diagnosing inferior vena caval (IVC) extension of tumour thrombus in patients with Wilms' tumour.
Over a 3-year period from June 1994 to June 1997, 74 patients with Wilms' tumour were referred to our institution. In this retrospective study we reviewed the preoperative colour flow Doppler ultrasound reports of 64 of these patients and compared the reports with the intra-operative findings in 51 patients who underwent surgery.
Vena caval extension of tumour thrombus was present in 12 patients (18.7%) and in six of these patients (9.4%) there was also atrial extension of the tumour. Colour flow Doppler ultrasound correctly diagnosed IVC extension of tumour thrombus in nine patients and correctly predicted the cranial extent of the tumour thrombus in eight patients.
Colour flow Doppler ultrasound has an overall positive predictive value of 73.4% in assessing IVC patency and correctly diagnosing IVC extension of tumour thrombus, in patients with Wilms' tumour. However, non-diagnostic ultrasound examinations can occur in over 20% of patients.
Wilms' tumor is the most common malignant renal tumor in children. Survival has improved dramatically over time as a result of prospective randomized clinical trials conducted by the pediatric cooperative cancer groups. Current research is directed toward identifying low-risk patients for whom a reduction in treatment intensity would decrease long-term morbidity. This article reviews the most recent advances in the biology and treatment of children with Wilms' tumor.
Wilms' tumor accounts for nearly 6% of all pediatric cancers and more than 95% of all kidney tumors in children. Fortunately, survival for patients with Wilms' tumor is generally excellent. This review will outline the results of prior clinical trials that have led to this excellent outcome and how information gleaned from these trials has led to the development of the current series of clinical trials for the management of children with Wilms' tumor.
Tumor stage and histologic subtype have long been recognized as important prognostic factors in Wilms' tumor. More recent evidence suggests that, in certain instances, patient age, tumor size, response to therapy, and genetic abnormalities, specifically the loss of genetic material on chromosomes 1p and 16q, provide additional prognostic information. These factors have, therefore, been incorporated into a new risk stratification system that is currently being used to assign patients with Wilms' tumor to specific protocol-based therapies.
Survival for patients with Wilms' tumor when considered as a whole, once less than 30%, is currently greater than 90%, with this dramatic improvement being due, in part, to the systematic manner in which the approach to therapy has evolved. Further refinement in therapy is being undertaken, with the current trials aiming to maintain the excellent survival for children being treated for Wilms' tumor, while minimizing therapy-related toxicity.
New advances in computerized tomography, including multidetector computerized tomography with 3-dimensional reformatting has recently called into question the absolute need for magnetic resonance imaging for evaluating renal cell carcinoma with suspected venous involvement. We assessed the accuracy of multidetector computerized tomography for predicting tumor thrombus and the level of venous involvement in patients with renal cell carcinoma.
We retrospectively reviewed clinical and pathological features in 41 patients with renal cell carcinoma who underwent staging multidetector computerized tomography before surgery. Multidetector computerized tomography findings regarding the presence and level of tumor thrombus were compared to findings at surgery and at final pathological evaluation. All multidetector computerized tomography studies were read by a single radiologist (EKF) before surgery.
When excluding patients with segmental venous involvement only, the concordance rate between multidetector computerized tomography and pathological findings was 84%. Multidetector computerized tomography accurately predicted the level of tumor thrombus in 26 of 27 patients (96%). Four cases of negative multidetector computerized tomography findings were up staged to renal vein involvement based on pathological findings. All 4 patients had early distal thrombi that did not change operative management.
Multidetector computerized tomography with 3-dimensional mapping is an effective imaging modality for accurately characterizing the level of venous thrombus in patients with renal cell carcinoma. This modality effectively identified patients with clinically significant venous thrombus. Patients with renal cell carcinoma in whom multidetector computerized tomography fails to detect tumor thrombus are unlikely to have a tumor thrombus found at surgery that would change the surgical approach.
Wilms' tumor is the most common renal tumor in children. Outcomes have improved dramatically over the past few decades, but important treatment questions remain. These include the role of molecular biologic markers in stratifying patients for therapy or targeting tumors for treatment. We present a summary of these advances and outline the current treatment of Wilm's tumor.
The medical literature and results of all cooperative group studies reporting treatment of children with Wilms' tumor were reviewed.
Overall survival exceeds 90% for most patients with nephroblastoma. However, outcomes for patients with rhabdoid tumors and diffuse anaplasia remain poor. The role of renal sparing surgery in patients with bilateral tumors is clear, but for children with unilateral tumors it continues to be defined.
Current protocols conducted by pediatric oncology groups are beginning to incorporate biologic features to stratify patients for therapy. Treatment strategies continue to focus on limiting late effects of treatment while maintaining an excellent survival. New therapies are needed to treat the high-risk patients who continue to have high relapse and mortality rates.
Accurate preoperative diagnosis of renal vein, vena caval, or intracardiac extension of Wilms' tumor allows the surgeon to better plan operative vascular control and assess the potential benefits of preoperative chemotherapy. Magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound were used to study four consecutive patients presenting with Wilms' tumor. Three had vena caval involvement, with one of these having a massive right atrial tumor thrombus. A fourth patient had renal vein involvement only. We found MRI to be superior to both CT and ultrasound for mapping intravascular extension of Wilms' tumor and for delineating nonvascular disease. Because of its noninvasiveness, multiplane imaging capabilities, and image contrast and resolution, MRI is a valuable complimentary imaging modality for the diagnosis and follow-up of patients with Wilms' tumor.
The records of children enrolled in the National Wilms' Tumor Study-3 who had Wilms' tumor and thrombosis into the renal vein were reviewed. There were 164 patients with gross involvement of the extrarenal vein and 47 patients with microscopic involvement, an incidence of 11.3% (211 of 1,865 evaluable patients). Two-year survival rates were 90, 79 and 72% for stages II, III and IV, respectively. The most important predictors of survival were histologic pattern and stage. Complete en bloc excision of the tumor and thrombus continues to be the most effective initial management.
We reviewed the records of 77 children enrolled in the National Wilms Tumor Study-3 who had involvement of the inferior vena cava with tumor thrombus. None of these patients received preoperative chemotherapy or radiotherapy. Ultrasonography and inferior venacavography were more helpful than computerized tomography in the preoperative diagnosis. The median followup for the group was 2.7 years. The 3-year survival rates for patients with intracaval involvement were determined by stage (88, 89 and 62 per cent for stages II, III and IV, respectively). The most important prognostic factor was histological type. The level of vena caval involvement had no effect on survival; all 16 patients with atrial involvement survived 3 or more years. We continue to recommend appropriate surgical excision of the tumor and thrombus when it is technically feasible.
Extension of Wilms' tumor through the inferior vena cava into the heart presents a formidable clinical challenge. Excision of such a tumor without provoking emobilization may require cardiopulmonary bypass (CPB). The completeness of excision and the likelihood of tumor embolization during operation guide subsequent radiation therapy (RT) and chemotherapy. To help define these issues, the clinical records of 15 patients enrolled in three National Wilms' Tumor Studies (NWTS) who had intracardiac tumor extension (ICE) were reviewed. The median age at diagnosis was 4 years. One patient had clear cell sarcoma (CCS); the remainder had favorable histologic findings (FH). The clinicopathologic stage was stage II in one patient, stage III in eight patients, and stage IV in six patients. ICE was detected before operation in six patients, during operation in five patients, and after operation in five patients. CPB was used in 10 patients. Eleven patients (73%) had operative complications, with major intraoperative hemorrhage occurring most often (six patients). Complications occurred less often when ICE was recognized before operation (three of six patients) than when it was not (eight of nine patients). Embolization occurred in only two patients. There were no operative deaths. The patient with CCS died. Eleven of 14 patients with FH survived, with an actuarial event-free, 2-year survival rate of 86%. There were no patients in the first NWTS. Of the six patients in the second NWTS (NWTS-2), four died (67%). All nine patients in the third NWTS (NWTS-3) survived, but follow-up was shorter (median 4 years 9 months vs. 2 years 7 months). No particular surgical procedure was associated with an increased death rate. This review suggests Wilms' tumor with ICE presents a formidable surgical undertaking but has a relatively good prognosis. Embolization is an uncommon event in ICE (two patients, 13.3%), allowing a planned operative approach. Echocardiography and ultrasonography provide accurate preoperative diagnosis. And ICE should be suspected in patients with extensive vena cava thrombosis or who have hypotension or heart failure during examination or surgery.
Involvement of renal vessels and the inferior vena cava (IVC) plays a decisive role during operative planning for removal of abdominal masses in pediatric patients. Advantages and limitations of MR angiography and color Doppler sonography for determining these factors were evaluated.
MR angiography and color Doppler sonography were performed preoperatively in 42 neonates, infants, and children with abdominal masses and were compared with spin-echo MR imaging and with surgical findings. Variables evaluated were anatomic variants, vessel displacement, patency of vessels, collateral circulation, and intravascular tumor extension. Quality of vessel visualization was assessed in vessels not affected by tumor.
In 88% of unaffected renal vessels, the entire vessel course could be visualized on MR angiography compared with 58% on color Doppler sonography and 43% on spin-echo MR imaging. In four of nine cases, color Doppler sonography revealed an accessory renal artery, whereas MR angiography revealed these variants in seven of nine cases. MR angiography showed 79% and color Doppler sonography 66% of displaced vessels. Unlike MR angiography, color Doppler sonography did not reveal five stenotic renal veins because they could not be completely imaged. In two cases, however, MR angiography falsely indicated an occlusion of the IVC, whereas color Doppler sonography showed residual flow.
Anatomic variants, vessel displacement, collateral circulation, and neoplastic vessel infiltration were revealed more accurately by MR angiography than by color Doppler sonography. In cases in which patency of the IVC is unclear on MR angiography, color Doppler sonography should also be performed.
To define the incidence and manifestations of and optimal therapy for children with intravascular extension of Wilms tumor.
Children on a collaborative study of Wilms tumor who had intravascular extension into the inferior vena cava (IVC) or atrium were identified. Surgical checklists and surgical and pathology reports were reviewed.
One hundred sixty-five of 2,731 patients had intravascular extension of Wilms tumor. The level of extension was IVC in 134 and atrium in 31. Sixty-nine had received preoperative therapy (55 with IVC extension and 14 with atrial extension) for a median of 8 weeks. Complications during preoperative chemotherapy were seen in five patients (tumor embolism and tumor progression in one each, and three with adult respiratory distress syndrome, one of which was fatal). The intravascular extension of the tumor regressed in 39 of 49 children with comparable pre- and posttherapy radiographic studies, including 7 of 12 in whom the tumor regressed from an atrial location, thus obviating the need for cardiopulmonary bypass. Surgical complications occurred in 36.7% of the children in the atrial group and 17.2% in the IVC group. The frequency of surgical complications was 26% in the primary resection group versus 13.2% in children with preoperative therapy. When all the complications of therapy were considered, including those that occurred during the interval of preoperative chemotherapy (one of the five also had a surgical complication), the incidence of complications among those receiving preoperative therapy was not statistically different from the incidence among those who underwent primary resection. The difference in 3-year relapse-free survival (76.9% for 165 patients with intravascular extension, 80.3% for 1,622 patients with no extension) was not statistically significant whether or not it was adjusted for stage and histology.
Preoperative treatment of these children may facilitate resection by decreasing the extent of the tumor thrombus, but the overall frequency of complications is similar in both groups.
To evaluate the accuracy of multidetector computed tomography (CT) and magnetic resonance imaging (MRI) in staging and estimating renal carcinomas with caval thrombus.
Initially, 23 patients with suspected caval thrombi were admitted into this prospective study. Triphasic CT imaging was performed using a multidetector CT with a reconstructed slice thickness of 2 mm. 3D CT reconstructions were used to improve surgical planning. MRI protocol included: a transversal T1-weighted GE sequence with and without Gd-DTPA, a transversal T2-weighted respiratory-gated TSE, and a coronal T1-weighted GE sequence with Gd-DTPA and fat saturation. In addition, a multiphase 3D angiography was performed after Gd-DTPA injection. Patients were divided into 3 groups: caval thrombus below the insertion of the hepatic veins, within the intrahepatic vena cava, and intra-atrial extension. The results the tumor thrombus extension and staging results of 2 independent readers were correlated with surgical and histopathological staging.
Of the 23 patients admitted, CT and MR scans of 14/13 patients respectively were correlated with histopathological workup. CT thrombus detection sensitivity and specificity for both readers was 0.93 and 0.8 respectively. MRI sensitivity and specificity for both readers was 1.0/0.85 and 0.75. Readers I and II evaluated the uppermost extension of the cranial tumor thrombus by both CT and MRI. CT and MR accuracy was 78% and 72%, 88% and 76% respectively.
In cases of a suspected tumor thrombus, MRI and multidetector CT imaging showed similar staging results. Consequently, these staging modalities can be used to assess the extension of the tumor thrombus.
To define the clinical characteristics and surgical management of intracaval involvement in patients enrolled in the UKW3 trial (1991-2001), which recommended elective preoperative chemotherapy for such cases.
Cases were identified from preoperative imaging and surgical trial forms. These asked specific questions about whether the surgeon suspected intracaval extension at diagnosis or found it at nephrectomy. For tumors with Wilms' histology, original case notes were examined.
Of 842 patients registered in UKW3, 730 (87%) had Wilms' tumor. Among them, 59 (8.1%) had evidence of intracaval extension, either documented at diagnosis (53) or found unexpectedly at nephrectomy (6). Intracaval extension was also seen in tumors of other histology. The level of thrombus was intraatrial (10), suprahepatic (9), retrohepatic (8), infrahepatic (26), and unknown (6). The median age at diagnosis was 3.75 years compared to 2.97 years in patients without inferior vena cava thrombus (P < .0001). Fifty-two of 59 received preoperative chemotherapy. Thirty-one (52%) needed cavotomy, and 3 (30%) with intraatrial extension required cardiopulmonary bypass. The commonest operative complication was significant hemorrhage and resulted in mortality in 3 cases.
Preoperative chemotherapy is a useful adjunct to shrink the tumor and thrombus. This reduces the requirement for cavotomy and cardiopulmonary bypass. Intraoperative hemorrhage remains a significant cause of operative morbidity and mortality.
Wilms tumour is one of the most common malignancies in children, with an excellent prognosis after therapy. There is a very diverse approach to treatment according to geographical location. This variation in therapeutic attitude toward Wilms tumour, particularly between the United States and Europe, has consequences for the choice of imaging modality at diagnosis. In Europe, the International Society of Paediatric Oncology (SIOP) treatment protocol is based on chemotherapy followed by surgery. Imaging (US, CT and MRI), clinical history and examination will help predict whether the findings are consistent with Wilms tumour. Furthermore, in the UK preoperative image-guided biopsy is advised to help identify the small group of patients who, despite typical imaging features of Wilms tumour, have other types of neoplasia that require alternative management. In the United States, the National Wilms Tumor Study (NWTS) advises surgery prior to chemo- and radiotherapy. Hence imaging must provide detailed anatomical information for surgical planning. This article discusses the role of imaging at diagnosis and the relative strengths and weaknesses of the available radiological techniques. We also focus on imaging the lung for metastatic disease and the consequences (to the patient's ultimate outcome) of CT-diagnosed small pulmonary nodules and discuss the radiological diagnosis and consequences of tumour rupture present at diagnosis.
Venous spread of renal cell carcinoma: MDCT Wilms Tumor Thrombus Detection 555 Pediatr Blood Cancer DOI 10
- Stern R Padovan
- D Perkov
- R Smiljanic
Stern Padovan R, Perkov D, Smiljanic R, et al. Venous spread of renal cell carcinoma: MDCT. Abdom Imaging 2007;32:530–537. Wilms Tumor Thrombus Detection 555 Pediatr Blood Cancer DOI 10.1002/pbc