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Thermal ablation has proven beneficial for hepatocellular carcinoma and possibly for colorectal liver metastases, but data is lacking for other liver metastases. Computer-assisted navigation can increase ablation efficacy and broaden its indications. We present our experience with percutaneous stereotactic image-guided microwave ablation (SMWA) for...
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Citations
... Microwave Ablation (MWA) -MWA makes use of electromagnetic microwaves for thermal ablation of LMs [94]. MWA has been used extensively for HCC and colorectal carcinoma, however there is limited study of its use in NELMs [95]. The studies that have been carried out so far suggest MWA may be superior to RFA in management of larger NELMs [96] and it is well established that MWA produces larger ablation zones and is less vulnerable to the "heat-sink" effect [97]. ...
Purpose of review
This article aims to illustrate the current state of investigations and management of liver metastases in patients with Neuroendocrine Neoplasms. Neuroendocrine tumours (NETs) are rising in incidence globally and have become the second most prevalent gastrointestinal malignancy in UK and USA. Frequently, patients have metastatic disease at time of presentation. The liver is the most common site of metastases for gastro-enteropancreatic NETs. Characterisation of liver metastases with imaging is important to ensure disease is not under-staged.
Recent Findings
Magnetic resonance imaging and positron emission tomography are now becoming standard of care for imaging liver metastases. There is an increasing armamentarium of therapies available for management of NETs and loco-regional therapy for liver metastases. The data supporting surgical and loco-regional therapy is reviewed with focus on role of liver transplantation.
Summary
It is important to use appropriate imaging and classification of NET liver metastases. It is key that decisions regarding approach to treatment is undertaken in a multidisciplinary team and that individualised approaches are considered for management of patients with metastatic NETs.
... To get full effect the electrodes should be placed as parallel as possible (15,16). The placement is guided by ultrasound (US), contrast enhanced ultrasound (CEUS), US images fused with computed tomography (CT) or magnetic resonance imaging (MRI), CT, MRI, or CT based stereotactic navigation systems (17)(18)(19) (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33). ...
We examined the correlation between decrease in tissue resistance and time to local tumor recurrence after irreversible electroporation (IRE) in patients with hepatocellular carcinoma (HCC) and colorectal cancer liver metastases (CRCLM). This population-based retrospective cohort study included consecutive patients treated with IRE for liver tumors in Sweden betweem 2011 and 2018. In total 149 patients with 206 tumors were treated. Exclusion due to missing and inaccurate data resulted in 124 patients with 170 tumors for the analyses. In a multivariable Cox regression model, a smaller decrease in tissue resistance (HR 1.02 (1.01-1.03), p=0.002) and tumors of size 21-30 mm (HR 2.48, 95% CI 1.26-4.88, p=0.009) and >30mm (HR 2.56, 95% CI 1.17-5.71, p= 0.019) were associated with shorter time to local tumor recurrence for CRCLM. This correlation was not seen for HCC. We found an association between a decrease in tissue resistance and time to local tumor recurrence for CRCLM. Our findings suggest that a decrease in tissue resistance, instead of rise in current, may be the parameter the interventionist should use during IRE to decide if the treatment is successful.
... A larger ablation area might account for a higher complication rate. [67,68] A defect of MWA is high local development of tumor which may be caused by a larger applicator (5 mm in diameter) applied for tumor puncture increasing the risk of bleeding and subsequent tumor seeding. [69] It should be noted that RFA is performed by the guidance of ultrasound, computed tomography or magnetic resonance imaging, while MWA is performed under computed tomography or ultrasound guidance, so the types of devices and the experience of the operators would also affect the results, and high-quality evidence is needed to compare the complication rates of MWA and RFA. ...
Background:
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Surgical resection is often only possible in the early stages of HCC and among those with limited cirrhosis. Radiofrequency ablation and Microwave ablation are 2 main types of percutaneous thermal ablation for the treatment of HCC. The efficacy and safety between these 2 therapy methods are still under a debate.
Objective:
To compare the efficacy and safety of Radiofrequency ablation and Microwave ablation in treating HCC.
Methods:
PubMed, EMBASE, the Cochrane databases and Web of Science were systematically searched. We included randomized controlled trials and cohort studies comparing the efficacy and safety of Radiofrequency ablation and Microwave ablation in HCC patients. Outcome measures on local tumor progression, complete ablation, disease-free survival, overall survival, or major complications were compared between the 2 groups. The random effect model was used when there was significant heterogeneity between studies, otherwise the fixed effect model was used.
Results:
A total of 33 studies, involving a total of 4589 patients were identified, which included studies comprised 7 RCTs, 24 retrospective observational trials, and 2 prospective observational trial. Microwave ablation had a lower local tumor progression than Radiofrequency ablation in cohort studies (OR = 0.78, 95% CI 0.64-0.96, P = .02). Complete ablation rate of Microwave ablation was higher than that of Radiofrequency ablation in cohort studies (OR = 1.54, 95% CI 1.05-2.25, P = .03). There was no significant difference in overall survival and disease-free survival between the 2 groups. Meta-analysis showed that there was no significant difference in the main complications between Microwave ablation and Radiofrequency ablation.
Conclusions:
Microwave ablation has higher complete ablation and lower local tumor progression than Radiofrequency ablation in the ablation treatment of HCC nodules. There was no significant difference in overall survival between the 2 therapy methods.
... Die intraoperative Navigation auf der Basis der 3-D-Modelle ist bei Ablationen insbesondere bei der stereotaktischen Ablation eine wertvolle Unterstützung, sodass die Erfolgsrate deutlich gesteigert werden kann [33,46,55,56,57]. Ein weiteres Einsatzgebiet bieten Metastasen, die durch eine durchgeführte Chemotherapie in der präoperativen Bildgebung nicht mehr abgegrenzt werden können. ...
Zusammenfassung
Durch die Optimierung der konservativen Behandlung, die Verbesserung der bildgebenden Verfahren und die Weiterentwicklung der Operationstechniken haben sich das operative Spektrum sowie der Maßstab für die Resektabilität in Bezug auf die Leberchirurgie in den letzten Jahrzehnten deutlich verändert.
Dank zahlreicher technischer Entwicklungen, insbesondere der 3-dimensionalen Segmentierung, kann heutzutage die präoperative Planung und die Orientierung während der Operation selbst, vor allem bei komplexen Eingriffen, unter Berücksichtigung der patientenspezifischen Anatomie erleichtert werden.
Neue Technologien wie 3-D-Druck, virtuelle und augmentierte Realität bieten zusätzliche Darstellungsmöglichkeiten für die individuelle Anatomie. Verschiedene intraoperative Navigationsmöglichkeiten sollen die präoperative Planung im Operationssaal verfügbar machen, um so die Patientensicherheit zu erhöhen.
Dieser Übersichtsartikel soll einen Überblick über den gegenwärtigen Stand der verfügbaren Technologien sowie einen Ausblick in den Operationssaal der Zukunft geben.
... Almost all diagnostic methods have been used either solely or in combination (with or without fusion imaging) for ablation guidance [4]. In the vast majority of ablation sessions, a conventional manual free-hand approach is performed; more recently, however, a stereotactic computer-assisted navigation has been applied, aiming to improve the precision of the needle placement [5][6][7][8][9][10]. The CT-navigation system allows for real-time treatment planning during the procedure and helps to avoid critical structures without angular limitations for an optimal trajectory [11]. ...
... The CT-navigation system allows for real-time treatment planning during the procedure and helps to avoid critical structures without angular limitations for an optimal trajectory [11]. General anesthesia or deep sedation seems to be a prerequisite for the application of this stereotactic, computer-assisted navigation [5][6][7][8][9][10][11]. Unfortunately, although anesthesiologists are best trained, they are not available to attend all ablation procedures [12]. ...
... Prerequisites contributing to the prevention of incomplete ablation include the location and diameter of the tumor, proximity to vessels, accurate positioning of the ablation antenna(s) in the tumor, sufficient energy deposition, and lastly evaluation of the ablation zone. The present study adds to the growing number of case series showing that percutaneous microwave ablation under stereotactic navigation is feasible, safe, and efficacious for the treatment of malignant liver lesions [5][6][7][8][9][10][11]. Perodin et al. retrospectively evaluated 23 patients (40 liver lesions) undergoing percutaneous stereotactic imaging-guided microwave ablation, reporting an incomplete ablation rate of only 2.5% [5]. ...
Background and Objectives: The aim of the present study was to report the safety and efficacy of percutaneous navigation under local anesthesia for computed tomography-guided microwave ablation of malignant liver lesions located in the hepatic dome. Patients with primary and secondary malignant liver lesions located in the hepatic dome who underwent percutaneous computed tomography-guided microwave ablation using a computer-assisted navigation system under local anesthesia were prospectively evaluated. The primary objective was technical success. Materials and Methods: The sample consisted of 10 participants (16 lesions) with a mean age of 60.60 years (SD = 9.25 years) and a mean size of 20.37 ± 7.29 cm, and the mean follow-up time was 3.4 months (SD = 1.41) months. Results: Primary technical success was 93.75%. Tumor remnant was noticed at one month follow-up in a single metastatic lesion, which was re-treated with an ablation session, and no tumor remnant was depicted in the subsequent imaging follow-up (secondary technical success 100%). Grade I self-limited complications (according to the CIRSE classification system) included small pleural effusion (n = 1) and minor bleeding post antenna removal (n = 1) requiring nothing but observation. Conclusions: the findings of the present study indicate that percutaneous navigation under local anesthesia is a safe and efficacious approach for computed tomography-guided microwave ablation of malignant liver lesions located in the hepatic dome. Large randomized controlled studies are warranted to observe treatment effectiveness and compare the results with those of other options.
... Lesion size >30 mm and targeting position error > 5 mm were significant influence factors for LTP, while a challenging location had no significant influence on LTP nor on targeting accuracy. The same group published two other studies using stereotactic MWA with remarkable results, one on their initial experiences with non-colorectal liver metastases (NCRLM) [30] and one with hepatocellular carcinoma [31]. Of 40 non-colorectal liver metastases in 23 patients with a median size of 1.4 cm only 4 (10%) showed LTP after a median follow-up of 15 months. ...
Thermal ablation is an emerging, potentially curative approach in treating primary and metastatic liver cancer. Different technologies are available, with radiofrequency ablation (RFA) and microwave ablation (MWA) being the most widely used. Regardless of the technique, destruction of the entire tumor, including an adequate safety margin, is key. In conventional single-probe US- or CT-guided thermal ablation, the creation of such large necrosis zones is often hampered by technical limitations, especially for large tumors (i.e., >2–3 cm). These limitations have been overcome by stereotactic RFA (SRFA): a multiple needle approach with 3D treatment planning and precise stereotactic needle placement combined with intraprocedural image fusion of pre- and post-interventional CT scans for verification of treatment success. With these sophisticated tools and advanced techniques, the spectrum of locally curable liver malignancies can be dramatically increased. Thus, we strongly believe that stereotactic thermal ablation can become a cornerstone in the treatment of liver malignancies, as it offers all the benefits of a minimally invasive method while providing oncological outcomes comparable to surgery. This article provides an overview of current stereotactic techniques for thermal ablation, summarizes the available clinical evidence for this approach, and discusses its advantages.
... However, RFA techniques have recently been improved by the assistance of 3D navigation systems, allowing better planning with multiple overlapping ablation zones, a more accurate placement of the probes and an assessment of the results intraoperatively, thanks to image fusion. This new generation of techniques is called "stereotactic RFA" [108,109,110]. ...
To evaluate the status of a liver tumor, we usually perform a biopsy followed by an anatomo-pathological evaluation of the extracted sample. However, the biopsy, due to the small sampling size, does not testify the intra and inter-tumor heterogeneity, thus struggling in assessing precisely the phenotypical characteristics of the patients. Recent progress in medical imaging and data science fields enabled the emergence of a new technique called radiomics, that is partially answering these challenges. In this thesis, we have been focusing on hepatocellular carcinoma, and we built new imaging methods to characterize this widespread pathology. By incorporating temporal information through multiphase images, specialized UNet-like networks have been stacked in a cascaded architecture to provide a semantic segmentation of both the liver and its internal tissue (parenchyma, active & necrotic part of the tumor). To characterize the strong heterogeneity that resides in the tumor, we predict the histological grade on a fine scale (slice-wise), by re-using the features learned from the semantic segmentation network. Our preliminary results enable the production of a fine-detailed map of the tumor that separates well differentiated areas from poorly ones. Even though these results need to be confirmed with a larger cohort, we believe that medical images combined with deep modeling techniques may soon be introduced in a clinical workflow to help diagnose and evaluate the phenotypical characteristics of pathologies such as liver cancer.
... Other locoregional therapies directed to ampullary liver metastases, such as percutaneous stereotactic image-guided MWA 87 and HAI 88 have been published in case reports or small case series that included other primary tumors. Thus, it is not possible to evaluate its prognostic significance. ...
The liver is the most common site of metastases from solid gastrointestinal tract tumors. Over the past few decades, the role of locoregional therapies, resection and thermal ablation, for neuroendocrine and colorectal liver metastases has been widely studied. However, for liver metastases originating from other gastrointestinal organs, the role of locoregional treatment remains unclear. This review summarizes and discusses the available evidence regarding benefits, risks, and indications for locoregional therapies for non-colorectal and non-neuroendocrine gastrointestinal liver metastases, highlighting the importance of multidisciplinary approach and patient selection.
... All of the 34 included works were single-centre studies, of which 26 were retrospective studies (29,30,(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)31,(49)(50)(51)(52)(53)(54)(32)(33)(34)(35)(36)(37)(38), 3 prospective case series (55)(56)(57), 3 prospective cohort studies(58-60) and 2 randomised controlled trials (61,62). Two studies reported results using a laparoscopic treatment access (44,55), the other 32 reporting on thermal ablations using a percutaneous approach. ...
Background: Stereotactic navigation techniques aim to enhance treatment precision and safety in minimally invasive thermal ablation of liver tumours. We qualitatively reviewed and quantitatively summarised the available literature on procedural and clinical outcomes after stereotactic navigated ablation of malignant liver tumours.
Methods: A systematic literature search was performed on procedural and clinical outcomes when using stereotactic or robotic navigation for laparoscopic or percutaneous thermal ablation. The online databases Medline, Embase and Cochrane Library were searched. Endpoints included targeting accuracy, procedural efficiency and treatment efficacy outcomes. Meta-analysis including subgroup analyses were performed.
Results: Thirty-four studies (2 randomised controlled trials, 3 prospective cohort studies, 29 case series) were qualitatively analysed and 22 studies included for meta-analysis. Weighted average lateral targeting error was 3.7mm (CI 3.2,4.2), with all four comparative studies showing enhanced targeting accuracy compared to free-hand targeting. Weighted average overall complications, major complications and mortality were 11.4% (6.7, 16.1), 3.4% (2.1, 5.1) and 0.8% (0.5, 1.3). Pooled estimates of primary technique efficacy were 94% (89, 97) if assessed at 1 – 6 weeks and 90% (87, 93) if assessed at 6 – 12 weeks post ablation, with significant remaining between-study heterogeneity. Pooled odds ratio of primary technique efficacy for stereotactic versus free-hand targeting was 1.9 (1.2, 3.2)(n = 6 studies).
Conclusions: Advances in stereotactic navigation technologies allow highly precise and safe tumour targeting, potentially leading to enhanced early treatment efficacy. The use of varying definitions and terminology limit comparability of safety and efficacy among studies, highlighting the crucial need for further standardization of follow-up definitions.
... To achieve the most accurate probe position, navigation systems can be a helpful tool [7][8][9][10][11][12][13] . An accurate placement of the probe is a precondition for a high primary efficacy. ...
Abstract In this study, we compare the primary efficacy of computed tomography-navigated stereotactic guidance to that of manual guidance for percutaneous microwave ablation of liver malignancies. In total, 221 patients (140, 17, and 64 with hepatocellular carcinoma, cholangiocellular carcinoma, and liver metastases, respectively) with 423 treated liver lesions underwent microwave ablation (MWA). Manual guidance (M) and stereotactic guidance (S) were used for 136 and 287 lesions, respectively. The primary endpoint was the primary efficacy and the secondary endpoint was the radiation dose. A generalised estimating equation was applied to analyse the correlation between the primary efficacy (lesion basis) and the type of guidance, size and location of lesion. The primary efficacy rate was significantly higher in the S-group (84.3%) than in the M-group (75.0%, p = 0.03). Lesion size > 30 mm was negatively correlated with the efficacy rate (odds ratio 0.38; 95% confidence interval 0.20–0.74). Stereotactic guidance was associated with a significantly lower dose length product (p
