Browsing by Author "Ozkok, Serdar"

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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-5195-2014
OBJECTIVES 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.
Lung Cancer in Turkey
(2022) Cangir, Ayten Kayi; Yumuk, Perran Fulden; Sak, Serpil Dizbay; Akyurek, Serap; Eralp, Yesim; Yilmaz, Ulku; Selek, Ugur; Eroglu, Atilla; Tatli, Ali Murat; Dincbas, Fazilet Oner; Kilickap, Saadettin; Sendur, Mehmet Ali Nahit; Dilektasli, Asli Gorek; Bozcuk, Hakan Sat; Ozkok, Serdar; Oztop, Ilhan; Topkan, Erkan; Dilege, Sukru; Kaya, Akin; Demirkazik, Ahmet; 36192076
Practice Patterns For Oropharyngeal Cancer in Radiation Oncology Centers of Turkey
(2014) Karakoyun-Celik, Omur; Altun, Musa; Olmezoglu, Ali; Buyukpolat, Mustafa Yakup; Ozkok, Serdar; Akmansu, Muge; Cengiz, Mustafa; Onal, Cem; Dizman, Aysen; Esassolak, Mustafa; https://orcid.org/0000-0002-2742-9021; 25076239; HOC-5611-2023
Aims and background. The aim of the study was to review the current clinical practices of radiation oncologists involved in the treatment of oropharyngeal cancer. Methods and study design. The daily practices of radiation oncology centers for patients diagnosed with oropharyngeal cancer in 2010 were evaluated by a two-part questionnaire that separately assessed the information of the participating center and the charts of the treated patients. Results. A total of 22 centers participated in the study, and 105 oropharyngeal cancer patients reported for our review. The use of positron emission tomography was a common practice in staging and radiotherapy planning. Multidisciplinary head and neck cancer clinics were available in 14 (64%) centers and were absent in 8 centers. Thirty-six of the 105 patients were not evaluated by a multidisciplinary clinic before the initiation of therapy, and adjuvant radiotherapy administration was found to be higher in this group. Percutaneous endoscopic gastrostomy tube placement was not a routine practice in any of the centers. Seventy-five patients received chemotherapy 46 concurrently with radiotherapy and 29 as induction chemotherapy. Two centers administered conventional radiotherapy alone, 20 centers conformal radiotherapy, and 7 centers were able to provide intensity-modulated radiotherapy. Conclusions. Across all the centers there were small differences in the pretreatment evaluation of patients with oropharyngeal cancer. The greatest difference was in the technical delivery of radiation, with most of the centers using conformal radiotherapy despite the increasing availability of intensity-modulated radiotherapy. The use of chemotherapy has more readily adopted the current international standards in the treatment of oropharyngeal cancer.
Review of Current Status of Radiotherapy Facilities and Assessment of Required Time for Radiotherapy Delivery Workflow in Turkey: On Behalf of Turkish Society for Radiation Oncology
(2015) Akman, Fadime; Onal, Cem; Kamer, Serra; Agaoglu, Fulya; Guney, Yildiz; Hicsonmez, Ayse; Koc, Mehmet; Oksuz, Didem C.; Ozyiğit, Gokhan; Ozkok, Serdar
The aim this study is to evaluate current status and workload of radiotherapy (RT) centers in Turkey, by assessing time and staff required during core treatment procedures in patients with different tumor sites. A survey sent via e-mail to all hospitals that are actively treating patients with RT, that aimed expose the details on type of the techniques being used and the time spent for treatment planning and delivery for the different techniques according to different tumor sites. The results were evaluated by several variables, the type of the center (university hospitals or state-run hospitals) and the number of patients treated per year per center (<1000 patients/year treated vs. 000 patients/year treated). The survey was sent to 48 centers and the return rate was 71% (34 centers). Average daily treatment course performed by one physician was 192 per year (range: 41 - 650). Median number of patients treated by a specialist per year was 210 (range: 79 - 650) in the university hospitals and 101 (range: 41 - 167) in the state-run hospitals. Median time spent for treating a patient with 3-dimensional conformal RT (3DCRT) was 4 h, and it was 5 h 45 min for intensity-modulated AT (IMRT). The time spent for all cancer types treated with 3DCRT and IMRT was higher in state-run hospitals compared to university hospitals. With increasing use of newer AT techniques, the time spent for treating patients increases. Besides adequate equipment, sufficient and well-trained staff is required to achieve these newer AT technique benefits for the patients.
The role of delineation education programs for improving interobserver variability in target volume delineation in gastric cancer
(2017) Onal, Cem; Cengiz, Mustafa; Guler, Ozan C.; Dolek, Yemliha; Ozkok, Serdar; 0000-0002-2742-9021; 0000-0001-6908-3412; 28339289; D-5195-2014; AAC-5654-2020
Objective: To assess whether delineation courses for radiation oncologists improve interobserver variability in target volume delineation for post-operative gastric cancer radiotherapy planning. Methods: 29 radiation oncologists delineated target volumes in a gastric cancer patient. An experienced radiation oncologist lectured about delineation based on contouring atlas and delineation recommendations. After the course, the radiation oncologists, blinded to the previous delineation, provided delineation for the same patient. Results: The difference between delineated volumes and reference volumes for pre-and post-course clinical target volume (CTV) were 19.8% (-42.4 to 70.6%) and 12.3% (-12.0 to 27.3%) (p = 0.26), respectively. The planning target volume (PTV) differences pre-and post-course according to the reference volume were 20.5% (-40.7 to 93.7%) and 13.1% (-10.6 to 29.5%) (p = 0.30), respectively. The concordance volumes between the pre-and post-course CTVs and PTVs were 467.1 +/- 89.2 vs 597.7 +/- 54.6cm(3) (p < 0.001) and 738.6 +/- 135.1 vs 893.2 +/- 144.6 cm(3) (p < 0.001), respectively. Minimum and maximum observer variations were seen at the cranial part and splenic hilus and at the caudal part of the CTV. The kappa indices compared with the reference contouring at pre- and post-course delineations were 0.68 and 0.82, respectively. Conclusion: The delineation course improved interobserver variability for gastric cancer. However, impact of target volume changes on toxicity and local control should be evaluated for further studies. Advances in knowledge: This study demonstrated that a delineation course based on current recommendations helped physicians delineate smaller and more homogeneous target volumes. Better target volume delineation allows proper target volume irradiation and preventing unnecessary normal tissue irradiation.
Treatment outcomes of prostate cancer patients with Gleason score 8-10 treated with definitive radiotherapy
(2019) Ozyigit, Gokhan; Onal, Cem; Igdem, Sefik; Alicikus, Zumre Arican; Iribas, Ayca; Akin, Mustafa; Yalman, Deniz; Cetin, Ilknur; Aksu, Melek Gamze; Atalar, Banu; Dincbas, Fazilet; Hurmuz, Pervin; Guler, Ozan Cem; Aydin, Barbaros; Sert, Fatma; Yildirim, Cumhur; Gorken, Ilknur Birkay; Agaoglu, Fulya Yaman; Korcum, Aylin Fidan; Yüce, Deniz; Ozkok, Serdar; Darendeliler, Emin; Akyol, Fadil; 31143994
Purpose To validate the clinical outcomes and prognostic factors in prostate cancer (PCa) patients with Gleason score (GS) 8-10 disease treated with external beam radiotherapy (EBRT)+ androgen deprivation therapy (ADT) in the modern era. Methods Institutional databases of biopsy proven 641 patients with GS 8-10 PCa treated between 2000 and 2015 were collected from 11 institutions. In this multi-institutional Turkish Radiation Oncology Group study, a standard database sheet was sent to each institution for patient enrollment. The inclusion criteria were, T1-T3N0M0 disease according to AJCC (American Joint Committee on Cancer) 2010 Staging System, no prior diagnosis of malignancy, at least 70Gy total irradiation dose to prostate +/- seminal vesicles delivered with either three-dimensional conformal RT or intensity-modulated RT and patients receiving ADT. Results The median follow-up time was 5.9 years (range 0.4-18.2 years); 5-year overall survival (OS), biochemical relapse-free survival (BRFS) and distant metastases-free survival (DMFS) rates were 88%, 78%, and 79%, respectively. Higher RT doses (>= 78Gy) and longer ADT duration (>= 2 years) were significant predictors for improved DMFS, whereas advanced stage was a negative prognosticator for DMFS in patients with GS 9-10. Conclusions Our results validated the fact that oncologic outcomes after radical EBRT significantly differ in men with GS 8 versus those with GS 9-10 prostate cancer. We found that EBRT dose was important predictive factor regardless of ADT period. Patients receiving 'non-optimal treatment' (RT doses <78Gy and ADT period <2 years) had the worst treatment outcomes.