Selcuk Demiral's research while affiliated with Ankara University Faculty of Sport Sciences and other places

Objective: In this study, we evaluated treatment volume determination for parametrial boosting in patients with locally advanced cervical cancer. Materials and Methods: Primary goal of this study has been to evaluate treatment volume determination for parametrial boosting based on CT only or fused CT-MRI in patients with locally advanced cervical cancer. We have carried out a comparative analysis of treatment volume determination by CT simulation images only or by integration of MRI. While we primarily focused on evaluation of incorporated multimodality imaging for treatment volüme determination, we also assessed critical organ contouring along with interobserver and intraobserver variations. Ground truth target volume has been utilized for comparative analysis, and it was determined by board certified radiation oncologists after detailed evaluation of all imaging and relevant data with thorough colleague peer review and consensus.

Objective: Hodgkin lymphoma is a critical malignancy which may be seen during childhood and adolescence. Since it may be observed in younger patients, treatment strategies should be considered thoroughly to achieve optimal results in terms of local control and treatment related adverse effects. Systemic therapy plays a critical role in treatment of Hodgkin lymphoma. In this study, we evaluated changes in tumor volume following chemotherapy for nodular sclerosing Hodgkin lymphoma (NSHL).

Background There is a paucity of data on the management of recurrent lymph nodes after primary or adjuvant radiotherapy (RT) for prostate cancer (PCa). In this study, we report our tertiary cancer center experience with stereotactic body radiotherapy (SBRT) for the management of pelvic lymph node recurrences after adjuvant or primary RT for PCa. Materials and Methods Patients who underwent SBRT for pelvic lymph node metastases from PCa between 2013 and 2019 were retrospectively assessed for local control (LC), androgen deprivation treatment-free survival (ADT-FS), and toxicity outcomes. The primary endpoint was LC and ADT-FS. The secondary endpoint was late treatment toxicity. Results Twenty-two lesions of 18 patients receiving SBRT for pelvic lymph node recurrences for PCa between February 2013 and March 2019 were evaluated. At a median follow-up duration of 29.5 months (range: 9–54 months), LC was 95.5% vs. 90.2% at 1 and 2 years, respectively. Ten patients received palliative ADT following SBRT after a median period of 14.5 months (range: 6–31 months). ADT-FS was 72.2% and 54.3% at 1 and 2 years, respectively. Comparative analysis of biologically effective dose (BED) values revealed that higher BED10 values were associated with higher ADT-FS ( P = 0.008). ADT-FS was 55.6% and 88.9% for BED10 <50 Gy and for BED10 >50 Gy, respectively ( P = 0.008). Assessment of late toxicity outcomes revealed that the most common toxicity was urinary toxicity and fatigue; however, no patient had ≥ grade 3 toxicity. Conclusion Our tertiary cancer center experience confirms the safety and efficacy of SBRT for the management of pelvic lymph node recurrences from PCa.

Background: Adaptive radiation therapy (ART) refers to redesigning of radiation therapy (RT) treatment plans with respect to dynamic changes in tumor size and location throughout the treatment course. In this study, we performed a comparative volumetric and dosimetric analysis to investigate the impact of ART for patients with limited-stage small cell lung cancer (LS-SCLC). Methods: Twenty-four patients with LS-SCLC receiving ART and concomitant chemotherapy were included in the study. ART was performed by replanning of patients based on a mid-treatment computed tomography (CT)-simulation which was routinely scheduled for all patients 20-25 days after the initial CT-simulation. While the first 15 RT fractions were planned using the initial CT-simulation images, the latter 15 RT fractions were planned using the mid-treatment CT-simulation images acquired 20-25 days after the initial CT-simulation. In order to document the impact of ART, target and critical organ dose-volume parameters acquired from this adaptive radiation treatment planning (RTP) were compared with the RTP based solely on the initial CT-simulation to deliver the whole RT dose of 60 Gy. Results: Statistically significant reduction was detected in gross tumor volume (GTV) and planning target volume (PTV) during the conventionally fractionated RT course along with statistically significant reduction in critical organ doses with incorporation of ART. Conclusion: One-third of the patients in our study who were otherwise ineligible for curative intent RT due to violation of critical organ dose constraints could be treated with full dose irradiation by use of ART. Our results suggest significant benefit of ART for patients with LS-SCLC.

Pilocytic astrocytoma (PA) may be seen in both adults and children as a distinct histologic and biologic subset of low-grade glioma. Surgery is the principal treatment for the management of PAs; however, selected patients may benefit from irradiation particularly in the setting of inoperability, incomplete resection, or recurrent disease. While conventionally fractionated radiation therapy has been traditionally utilized for radiotherapeutic management, stereotactic irradiation strategies have been introduced more recently to improve the toxicity profile of radiation delivery without compromising tumor control. PAs may be suitable for radiosurgical management due to their typical appearance as well circumscribed lesions. Focused and precise targeting of these well-defined lesions under stereotactic immobilization and image guidance may offer great potential for achieving an improved therapeutic ratio by virtue of radiosurgical techniques. Given the high conformality along with steep dose gradients around the target volume allowing for reduced normal tissue exposure, radiosurgery may be considered a viable modality of radiotherapeutic management. Another advantage of radiosurgery may be the completion of therapy in a usually shorter overall treatment time, which may be particularly well suited for children with requirement of anesthesia during irradiation. Several studies have addressed the utility of radiosurgery particularly as an adjuvant or salvage treatment modality for PA. Nevertheless, despite the growing body of evidence supporting the use of radiosurgery, there is need for a high level of evidence to dictate treatment decisions and establish its optimal role in the management of PA. Herein, we provide a concise review of radiosurgery for PA in light of the literature.

Lung cancer is a global health concern as the leading cause of cancer related mortality worldwide. Small cell lung cancer (SCLC) poses a formidable challenge to the treating physicians with the worst prognosis among all lung cancers. However, limited stage SCLC (LS-SCLC) has a relatively better outcome with multimodality management. Efforts have been focused on optimal integration of treatment modalities to achieve an improved therapeutic ratio for patients with LS-SCLC. While chemotherapy and thoracic radiation therapy (TRT) are primary components of initial management for LS-SCLC, there is no consensus on optimal timing of TRT. Within this context, we herein provide a concise overview of current evidence and future prospects regarding the optimal timing of thoracic irradiation for LS-SCLC in light of the literature.

Coronavirus disease 2019 (COVID-19) pandemic, which has emerged in December 2019 in the city of Wuhan, China, has significantly affected healthcare systems and economies within a short timeframe. Treatment strategies offer alleviation of symptoms in the absence of commercially available specific antiviral agents. Within this context, the introduction of innovative therapeutic approaches against the SARS-CoV-2 virus is a critical need that should be addressed urgently. The anti-inflammatory effect of low dose irradiation has been proposed as a potential therapeutic strategy for COVID-19 pneumonia. Consideration of external beam irradiation for management of COVID-19 pneumonia has prompted the investigation of alternative methods of irradiation with potentially improved toxicity profiles. Theoretically, targeted radiotherapy may have several advantages over conventional external beam radiotherapy owing to the capability to deliver effective radiation doses without adverse irradiation effects. Since radionuclides are conjugated to targeting vectors, such as antibodies and cell surface receptor binding peptides, irradiation may be focused on targeted cells with optimal sparing of surrounding normal tissues. In the context of COVID-19 management, targeted irradiation is expected to compromise SARS-CoV-2 extracellular virions. Targeted radiotherapy may offer a viable means of combating against SARS-CoV-2 virus. There is room for improvement with the need for efficacy, feasibility, and toxicity studies. Although targeted radiotherapy itself may not achieve absolute eradication of virus or virus-infected cells, it may at least serve as a supplementary therapeutic strategy that could be utilized in combination with other antiviral treatments. Further investigations focusing on nuclear medicine, radiopharmaceuticals, and targeted radiotherapy strategies may pave the way for the development of efficacious antiviral treatments which may be utilized in the battle against the current COVID-19 pandemic.