PubMed İndeksli Yayınlar Koleksiyonu

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    Treatment Outcomes of Stereotactic Body Radiotherapy in Patients with Synchronous and Metachronous Oligometastatic Renal Cell Carcinoma
    (2023) Guler, Ozan Cem; Oymak, Ezgi; Hurmuz, Pervin; Yavas, Guler; Tilki, Burak; Yavas, Cagdas; Ozyigit, Gokhan; Onal, Cem; 0000-0002-2742-9021; 36455527; D-5195-2014
    Introduction: The aim of this study was to investigate the clinical outcomes of metastasis-directed therapy (MDT) using stereotactic body radiotherapy (SBRT) in patients with synchronous or metachronous oligometastatic renal cell carcinoma (RCC). Methods: The clinical data of 87 patients with 138 lesions who received MDT between February 2008 and January 2019 were retrospectively analyzed. All patients had <= 5 metastasis at diagnosis (synchronous) or during progression (metachronous) and were treated with SBRT for their metastasis. The primary endpoints were local control (LC) and progression-free survival (PFS). The secondary endpoint was overall survival (OS). Results: Median follow-up was 20.4 months for entire cohort and 27.2 months for survivors. Synchronous oligometastatic disease was observed in 35 patients (40.2%), and 52 patients (59.8%) had metachronous disease. Seventy-two patients (82.8%) received systemic treatment synchronously or after MDT, while 15 patients (17.2%) did not receive any systemic treatment. The 1- and 2-year OS rates were 79.4% and 58.1%, respectively, and the 1- and 2-year PFS rates were 58.6% and 15.1%, respectively. The 1- and 2-year LC rates per lesion were 96.6% and 91.4%, respectively. There were no significant differences in survival between patients with synchronous oligometastasis and those with metachronous oligometastasis. All disease progressions were observed at a median time of 31.6 months (range: 1.9-196.9 months) after the completion of SBRT. Patients with solitary oligometastasis had significantly better OS compared to patients with >1 metastasis (p = 0.04). No patients experienced grade 3 or higher acute or late toxicities. Conclusion: SBRT is a successful treatment for oligometastatic RCC patients due to its excellent LC and minimal toxicity profile. There were no statistically significant survival differences between patients with synchronous and metachronous oligometastasis. Patients with solitary oligometastasis outlived their counterparts.
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    Bone Only Oligometastatic Renal Cell Carcinoma Patients Treated with Stereotactic Body Radiotherapy: A Multi Institutional Study
    (2022) Onal, Cem; Guler, Ozan Cem; Hurmuz, Pervin; Yavas, Guler; Tilki, Burak; Oymak, Ezgi; Yavas, Cagdas; Ozyigit, Gokhan; 0000-0002-2742-9021; 35695908; D-5195-2014
    Purpose This study aimed to analyze the prognostic factors associated with overall survival (OS) and progression-free survival (PFS) in patients with bone-only metastatic renal cell carcinoma (RCC) who have five or fewer lesions treated with stereotactic body radiotherapy (SBRT). Methods The clinical data of 54 patients with 70 bone metastases undergoing SBRT treated between 2013 and 2020 with a dose of at least 5 Gy per fraction and a biologically effective dose (BED) of at least 90 Gy were retrospectively evaluated. Results The majority of lesions were located in the spine (57.4%) and had only one metastasis (64.8%). After a median follow-up of 22.4 months, the 1- and 2-year OS rates were 84.6% and 67.3%, respectively, and median OS was 43.1 months. The 1- and 2-year PFS rates and median PFS were 63.0%, 38.9%, and 15.3 months, respectively. In SBRT-treated lesions, the 1-year local control (LC) rate was 94.9%. Age, metastasis localization, and number of fractions of SBRT were significant prognostic factors for OS in univariate analysis. In multivariate analysis, patients with spinal metastasis had better OS compared to their counterparts, and patients who received single-fraction SBRT had better PFS than those who did not. No patient experienced acute or late toxicities of grade 3 or greater. Conclusion Despite excellent LC at the oligometastatic site treated with SBRT, disease progression was observed in nearly half of patients 13 months after metastasis-directed local therapy, particularly as distant disease progression other than the treated lesion, necessitating an effective systemic treatment to improve treatment outcomes.
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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.