Scopus Açık Erişimli Yayınlar
Permanent URI for this collectionhttps://hdl.handle.net/11727/10760
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Item Cardiac angiosarcoma treated with 1.5 Tesla MR-guided adaptive stereotactic body radiotherapy-Case report and review of the literature(2022) Noyan, Asli; Yavas, Guler; Arslan, Gungor; Yavas, Cagdas; Onal, Cem; 0000-0002-2742-9021; 36027835; D-5195-2014Introduction: Cardiac angiosarcoma is a very rare disease. As a result of their nonspecific presentation symptoms, and the lack of consensus in treatment, caution should be taken in both diagnosis and treatment. The role of radiotherapy (RT) is debatable due to the continuous movement of the heart, which makes it difficult to safely deliver high radiation doses to the target volume.Presentation of case: The case of a 16-year-old boy with cardiac angiosarcoma that recurred one year after surgery and was treated with chemotherapy is presented. The patient received high field 1.5-Tesla (magnetic resonance) MR-Linac treatment in 5 fractions with a dosage of 25 Gy to the tumor bed and 30 Gy to the recurrent nodules using the simultaneous integrated boost technique. The patient tolerated the treatment well and had stable disease two months later. Discussion: MR-guided radiotherapy, particularly in the case of cardiac malignancies, allows for direct tumor visualization with high soft tissue image resolution capacity. Furthermore, modern RT techniques allow for the full therapeutic window to be used by achieving superior dose distributions, allowing for dose escalation stra-tegies with tolerable toxicity rates.Conclusion: Magnetic resonance guided RT allows direct visualization of the target during treatment delivery, allowing for higher-dose administration with less damage to healthy tissue near the tumor. This treatment strategy is a viable option in selected patients with cardiac angiosarcoma.Item The utility of 1.5 tesla MR-guided adaptive stereotactic body radiotherapy for recurrent ovarian tumor - Case reports and review of the literature(2022) Yavas, Guler; Kuscu, Ulku Esra; Ayhan, Ali; Yavas, Cagdas; Onal, Cem; 36261943Introduction: Although epithelioid ovarian cancer (EOC) is a radiosensitive tumor and radiotherapy (RT) played a significant role in adjuvant treatment management in the past, the role of RT has evolved with the advent of platinum-based chemotherapy regimens. Nonetheless, modern RT techniques may be useful in certain patients particularly those with recurrent disease.Presentation of case: After surgery and chemotherapy, two patients, aged 57 and 70, presented with recurrent lesions in the parailiac region. The recurrent lesions were treated with high field 1.5-Tesla MR-Linac treatment in 5 fractions at a dose of 30 Gy. The patients tolerated the treatment well and were disease free after 12 and 20 months of magnetic resonance guided radiotherapy (MRgRT), respectively.Discussion: MRgRT is a novel and rapidly evolving technology that allows for the highly precise treatment of even mobile targets through direct visualization of the tumor. The majority of patients with EOC frequently present with abdominal-pelvic recurrences. It has been demonstrated that EOC requires high radiation doses for curative treatment. MR-Linac enables monitoring of organ motion during treatment, which is necessary for delivering higher doses to target volumes while sparing surrounding organs.Conclusion: To reduce radiation doses to nearby normal tissues, MRgRT allows for the delivery of hypofractio-nated RT with tight safety margins. Regardless of initial resistance or gradual development of intolerance to standard chemotherapy regimens, the role of RT in patients with persistent or recurrent EOC should be reconsidered.Item Vaginal cuff brachytherapy practice in endometrial cancer patients: a report from the Turkish Oncology Group(2021) Bolukbasi, Yasemin; Onal, Cem; Ozsaran, Zeynep; Senyurek, Sukran; Akdemir, Eyub Yasar; Selek, Ugur; Yildiz, Ferah; 33897788Purpose: The American Brachytherapy Association is attempting to develop standards for delivering brachytherapy, although differences in practice have been reported in the literature. This study evaluated vaginal cuff brachytherapy (VBT) practice and quality of life-related recommendations among Turkish radiation oncologists. Material and methods: A nationwide web-based 17-item survey was distributed to the members of the Turkish Society for Radiation Oncology. These members received e-mail notifications, and a link was posted on the Turkish Society for Radiation Oncology internet site to solicit voluntary responses The survey addressed the simulation processes, target volume, prescribed dose, delivery schedules, and recommendations related to vaginal side effects. Results: Fifty-seven radiation oncologists responded to the survey. The most used dose fraction schemes for adjuvant VBT were 7 Gy x 3 fractions (30%), 5.5 Gy x 5 fractions (26%), and 6 Gy x 5 fractions (28%). The preferred VBT scheme was 5 Gy x 3 fractions (50%) when the external beam radiotherapy (EBRT) dose was 45 Gy external radiotherapy, while the preferred schemes were 6 Gy x 3 fractions (30%) or 5 Gy x 3 fractions (32%) when the external radiotherapy dose was increased to 50.4 Gy. One-half of the respondents delivered VBT twice a week, and the dose was prescribed to 0.5 cm from vaginal mucosa by 86% of the respondents. There was no common definition for the dose prescription length, which was defined as 3 cm from the vaginal cuff in 33% of responses and as 4 cm in 35% of responses. For serous and clear cell histological types, 38% of the respondents targeted "full cylinder length". To prevent vaginal side effects, 78% of the respondents recommended using a vaginal dilator and/or sexual intercourse after VBT. Conclusions: This survey revealed variations in the clinical practice of VBT among Turkish radiation oncologists, which suggests that standardization is necessary.Item The Potential Role Of MR-Guided Adaptive Radiotherapy In Pediatric Oncology: Results From A SIOPE-COG Survey(2021) Seravalli, Enrica; Kroon, Petra S.; Buatti, John M.; HalL, Matthew D.; Mandeville, Henry C.; Marcus, Karen J.; Onal, Cem; Ozyar, Enis; Paulino, Arnold C.; Paulsen, Frank; Saunders, Daniel; Tsang, Derek S.; Wolden, Suzanne L.; Janssens, Geert O.; 34159265Background and purpose: Magnetic resonance guided radiotherapy (MRgRT) has been successfully implemented for several routine clinical applications in adult patients. The purpose of this study is to map the potential benefit of MRgRT on toxicity reduction and outcome in pediatric patients treated with curative intent for primary and metastatic sites. Materials and methods: Between May and August 2020, a survey was distributed among SIOPE- and COG-affiliated radiotherapy departments, treating at least 25 pediatrics patients annually and being (candidate) users of a MRgRT system. The survey consisted of a table with 45 rows (clinical scenarios for primary (n = 28) and metastatic (n = 17) tumors) and 7 columns (toxicity reduction, outcome improvement, PTV margin reduction, target volume daily adaptation, online re-planning, intrafraction motion compensation and on-board functional imaging) and the option to answer by 'yes/no'. Afterwards, the Dutch national radiotherapy cohort was used to estimate the percentage of pediatric treatments that may benefit from MRgRT. Results: The survey was completed by 12/17 (71% response rate) institutions meeting the survey inclusion criteria. Responders indicated an 'expected benefit' from MRgRT for toxicity/outcome in 7% (for thoracic lymphomas and abdominal rhabdomyosarcomas)/0% and 18% (for mediastinal lymph nodes, lymph nodes located in the liver/splenic hilum, and liver metastases)/0% of the considered scenarios for the primary and metastatic tumor sites, respectively, and a 'possible benefit' was estimated in 64%/46% and 47%/59% of the scenarios. When translating the survey outcome into a clinical perspective a toxicity/outcome benefit, either expected or possible, was anticipated for 55%/24% of primary sites and 62%/38% of the metastatic sites. Conclusion: Although the benefit of MRgRT in pediatric radiation oncology is estimated to be modest, the potential role for reducing toxicity and improving clinical outcomes warrants further investigation. This fits best within the context of prospective studies or registration trials.