PubMed İndeksli Yayınlar Koleksiyonu

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    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-5195-2014
    Introduction: 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.
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    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; 36261943
    Introduction: 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.
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    A multi-institutional analysis of sequential versus 'sandwich' adjuvant chemotherapy and radiotherapy for stage IIIC endometrial carcinoma
    (2019) Onal, Cem; Sari, Sezin Yuce; Yildirim, Berna Akkus; Yavas, Guler; Gultekin, Melis; Guler, Ozan Cem; Akyurek, Serap; Yildiz, Ferah; 0000-0002-2742-9021; 30887753; D-5195-2014
    Objective: To analyze the outcomes of sequential or sandwich chemotherapy (ChT) and radiotherapy (RT) in patients with node-positive endometrial cancer (EC). Methods: Data from 4 centers were collected retrospectively for 179 patients with stage IIIC EC treated with postoperative RT and ChT (paclitaxel and carboplatin). Patients were either treated with 6 cycles of ChT followed by RT (sequential arm; 96 patients) or with 3 cycles of ChT, RT, and an additional 3 cycles of ChT (sandwich arm; 83 patients). Prognostic factors affecting overall survival (OS) and progression-free survival (PFS) were analyzed. Results: The 5-year OS and PFS rates were 64% and 59%, respectively, with a median followup of 41 months (range, 5-167 months). The 5-year OS rates were significantly higher in the sandwich than sequential arms (74% vs. 56%; p=0.03) and the difference for 5-year PFS rates was nearly significant (65% vs. 54%; p=0.05). In univariate analysis, treatment strategy, age, International Federation of Gynecology and Obstetrics (FIGO) stage, pathology, rate of myometrial invasion, and grade were prognostic factors for OS and PFS. In multivariate analysis, non-endometrioid histology, advanced FIGO stage, and adjuvant sequential ChT and RT were negative predictors for OS, whereas only non-endometrioid histology was a prognostic factor for PFS. Conclusion: Postoperative adjuvant ChT and RT for stage IIIC EC patients, either given sequentially or sandwiched, offers excellent clinical efficacy and acceptably low toxicity. Our data support the superiority of the sandwich regimen compared to the sequential strategy in stage IIIC EC patients for OS.