Tıp Fakültesi / Faculty of Medicine
Permanent URI for this collectionhttps://hdl.handle.net/11727/1403
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Item Daily Workflow and Workload of Radiation Oncology Specialists in Turkey(2015) Akman, Fadime; Kamer, Serra; Onal, Cem; Agaoglu, Fulya; Guney, Yildiz; Hicsonmez, Ayse; Koc, Mehmet; Colpan Oksuz, Didem; Ozyigit, Gokhan; Ozkok, Serdar; 0000-0002-2742-9021; D-5195-2014OBJECTIVES This study aimed to research the effort required by patient evaluation, radiotherapy planning and treatment processes in the daily applications of radiation oncology in terms of time, and to use this effort as the primary source for human power and infrastructure planning required in radiotherapy. METHODS The surveys carried out by Turkish Radiation Oncology Association Proficiency Board, Curriculum Preparation and Evaluation Commission on Education Institutions, Surveys delivered to the officers of the center via electronic mail, were answered and evaluated in accordance with the data of 2012. RESULTS 26 University and 8 Ministry of Health Hospitals participated in the study. The total number of specialists employed in the participant centers, were 227. For per specialist, 383 hours in a year were spent for the patients at follow-up, 334 hours were spent for the patients that were in treatment, and 950 hours were spent for planning and treatment set-ups. It was determined that the time spent for per patient in intensity modulated radiotherapy technique, was 2-3 times more when compared to the location of tumor, which is a conformal technique. It was observed that this duration was much longer in special radiotherapy applications such as brachytherapy, total body irradiation and radiosurgery. CONCLUSION Technological advancements in radiotherapy, require more effort and working time for new job descriptions and in daily practice.Item 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-5195-2014Introduction: 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.Item 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-5195-2014Purpose 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.Item The Role Of Stereotactic Body Radiotherapy In Switching Systemic Therapy For Patients With Extracranial Oligometastatic Renal Cell Carcinoma(2022) Onal, Cem; Hurmuz, Pervin; Guler, Ozan Cem; Yavas, Guler; Tilki, Burak; Oymak, Ezgi; Yavas, Cagdas; Ozyigit, Gokhan; https://orcid.org/0000-0002-2742-9021; 35119653; D-5195-2014Background Targeting oligometastatic lesions with metastasis-directed therapy (MDT) using stereotactic-body radiotherapy (SBRT) may improve treatment outcomes and postpone the need for second-line systemic therapy (NEST). We looked at the results of oligometastatic renal cell carcinoma (RCC) patients who had five or fewer lesions and were treated with SBRT. Methods We examined the treatment outcomes of 70 extracranial metastatic RCC (mRCC) patients treated at two oncology centers between 2011 and 2020. The clinical parameters of patients with and without NEST changes were compared. The prognostic factors for overall survival (OS), progression-free survival (PFS), and NEST-free survival were evaluated. Results Median age was 67 years (range 31-83 years). Lung and bone metastasis were found in 78.4% and 12.6% of patients, respectively. With a median follow-up of 21.1 months, median OS was 49.1 months and the median PFS was 18.3 months. Histology was a prognostic factor for OS, BED, and treatment switch for PFS in univariate analysis. In multivariate analysis, the significant predictor of poor OS was clear cell histology, and a lower BED for PFS. Following SBRT for oligometastatic lesions, 19 patients (27.2%) had a median NEST change of 15.2 months after MDT completion. There were no significant differences in median OS or PFS between patients who had NEST changes and those who did not. No patient experienced grade >= 3 acute and late toxicities. Conclusions The SBRT to oligometastatic sites is an effective and safe treatment option for <= 5 metastases in RCC patients by providing favorable survival and delaying NEST change.Item Role of 68-Ga-PSMA-PET/CT in pelvic radiotherapy field definitions for lymph node coverage in prostate cancer patients(2020) Onal, Cem; Ozyigit, Gokhan; Guler, Ozan Cem; Hurmuz, Pervin; Torun, Nese; Tuncel, Murat; Dolek, Yemliha; Yedekci, Yagiz; Oymak, Ezgi; Tilki, Burak; Akyol, Fadil; 0000-0002-2742-9021; 0000-0001-6908-3412; 32861704; AAE-2718-2021; D-5195-2014; AAC-5654-2020Purpose: To evaluate the distribution of metastatic lymph nodes (LN) detected on Ga-68-PSMA-positron emission tomography/computed tomography (PET/CT) in treatment-naive prostate cancer (PC) patients and to analyze the LN coverage rates of the pelvic fields defined in the GETUG trial and RTOG guidelines and a pelvic field extending superiorly from the L4/L5 interspace. Materials and methods: Ga-68-PSMA-PET/CT images obtained at diagnosis of 138 PC patients were retro-spectively analyzed. The number and locations of Ga-68-PSMA-positive LNs were co-registered with one single-planning CT. The numbers, locations, and sizes of LNs located outside the three pelvic volumes were investigated for the entire cohort and for patients with LN metastasis in the pelvic area only. Results: A total of 441 PSMA-PET-positive LN metastases were identified. The most frequent metastatic LNs were internal iliac LNs (25.2%). Para-aortic and presacral LNs outside the three pelvic fields were present in 20 (14.5%) and 22 patients (15.9%), respectively. The LN coverage rates according to the GETUG trial, the RTOG guidelines, and the pelvic field extending superiorly from L4/L5 were 44.2%, 52.2%, and 71, respectively, in the entire cohort and 51.7%, 61 and 83.1%, respectively, in patients with only pelvic LN metastasis. The number of metastatic LNs was a predictive factor for LNs located outside the three pelvic fields. Conclusions: Extending the cranial margin of the pelvic field from L5/S1 to L4/L5 increases the accuracy of pelvic field irradiation in approximately 20% of patients, highlighting the importance of proximal common iliac irradiation, particularly in patients with multiple LN metastasis. (C) 2020 Elsevier B.V. All rights reserved.Item Radiotherapy After Skin-Sparing Mastectomy and Implant-Based Breast Reconstruction(2019) Sari, Sezin Yuce; Guler, Ozan Cem; Gultekin, Melis; Yildirim, Berna Akkus; Onal, Cem; Ozyigit, Gokhan; Yildiz, Ferah; 0000-0001-6908-3412; 31255547; AAC-5654-2020We aimed to evaluate the cosmetic results of radiotherapy in 170 breast cancer patients after implant-based reconstruction. Cosmetic results were excellent or fair in most patients after radiotherapy. However, bolus use, lymphatic irradiation, and the volume receiving at least 110% of the prescribed dose being >1% significantly deteriorated the outcomes. Introduction: We evaluated the cosmetic results of radiotherapy (RT) after implant-based reconstruction (IBR). Patients and Methods: We retrospectively evaluated 170 patients with 171 breast cancers treated between December 2004 and January 2016 in 2 university hospitals. RT fields were reconstructed breast (RB) only in 24 (14%), and RB and regional lymphatics in 147 (86%) breasts, respectively. All but 1 patient received a total 50 Gy with conventional fractionation. All patients received systemic chemotherapy. One hundred thirty-eight (81%) patients received hormonal therapy; 118 tamoxifen and 20 aromatase inhibitor. Results: Median follow-up time was 46.8 months (range, 1-163 months). The 5-year disease-free and overall survival rate was 83% and 93%, respectively. Cosmetic results were considered excellent in 111 (65%), fair in 46 (27%), and bad in 14 (8%) RB by patients. Thirty-four (20%) RB had restorative surgery; because of surgeons' preference because of implant natural life time span in 5, and contracture, fibrosis, deformation, or dislocation of the implant, or cellulitis in the remaining. Statistically significant adverse factors in univariate analysis for impaired cosmetic outcome were bolus use on the RB, lymphatic irradiation, and volume that received at least 110% of the prescribed dose being >1%. The use of bolus material was the only prognostic factor for deterioration of the cosmetic result in multivariate analysis. Conclusion: RT after IBR yields acceptable cosmetic results. Although only 111 (65%) of RBs were considered to have excellent cosmetic results, only a small percentage of patients needed reoperation because of bad cosmetic outcome. (C) 2019 Elsevier Inc. All rights reserved.