Fakülteler / Faculties
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Item Prevention of Radiation-Induced Retinopathy with Amifostine in Wistar Albino Rats(2015) Yildirim, Berna Akkus; Cetin, Eren; Topkan, Erkan; Ozyigit, Gokhan; Cengiz, Mustafa; Surucu, Selcuk; Usubutun, Alp; Akyol, Fadil; 0000-0001-6661-4185; 25768249; V-5717-2017Item 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-5611-2023Aims 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.Item Restaging of Cervical Cancer Patients Treated with Adjuvant Radiotherapy According to FIGO 2018 and Suggestions for the Next Staging: Turkish Society for Radiation Oncology Gynecologic Group Study (TROD 04-004)(2022) Alanyali, Senem; Balci, Beril; Esen, Caglayan Selenge Beduk; Gultekin, Melis; Yildirim, Berna Akkus; Ozkurt, Selnur; Ergen, Sefika Arzu; Gursel, Sukriye Bilge; Cetin, Ilknur Alsan; Sert, Fatma; Sari, Sezin Yuce; Ibis, Kamuran; Onal, Cem; Sahinler, Ismet; Yildiz, Ferah; Ozsaran, ZeynepOBJECTIVE The objective of this study was to compare Federation of Gynecology and Obstetrics (FIGO) 2009 and 2018 staging systems in patients with uterine cervical cancer. METHODS Medical records of 571 patients who were treated with adjuvant radiotherapy or radiochemotherapy between 2001 and 2018 were retrospectively reviewed. Differences in overall survival (OS) and progression-free survival (PFS) rates according to FIGO 2009 and FIGO 2018 staging systems were compared using the log-rank test. Cox regression model was used to identify independent prognostic factors for survival. RESULTS The median follow-up was 59 months. Five-year OS and PFS rates were 81.1% and 77.7%, respectively. Stage migration was recorded in 401 patients (70.2%) and the most remarkable stage migration was detected in stage I patients (60%). A total of 157 (27.5%) patients upstaged to stage IIIC disease. According to FIGO 2009, 5-year OS rates were 87.3%, 80.5% (p=0.076), and PFS rates were 82.8%, 77.5% (p=0.036) for stage IB1 and IB2, respectively. According to FIGO 2018, the 5-year OS rates for stage IB1, IB2, and IB3 were 89.8%, 87.1%, and 81.4% (p=0.310), and PFS rates were 90.2%, 80.5%, and 80.1% (p=0.189), respectively. Patients with >= 2 pelvic lymph node (LN) metastases had worse 5-year OS and PFS rates than patients with one metastasis (p=0.015 and p=0.006). Number of para-aortic LN metastasis and metastatic LN ratio (MLNR) were also correlated with 5-year OS and PFS. CONCLUSION Current FIGO staging system better discriminates patients with cervical cancer. However, integration of metastatic LN number and/or MLNR to the upcoming FIGO staging system may improve the prognostic value of the staging.Item Retrospective Comparison of Standard and Escalated Doses of Radiotherapy in Newly Diagnosed Glioblastoma Patients Treated with Concurrent and Adjuvant Temozolomide(2019) Guler, Ozan Cem; Yildirim, Berna Akkus; Onal, Cem; Topkan, Erkan; https://orcid.org/0000-0001-6908-3412; https://orcid.org/0000-0001-6661-4185; https://orcid.org/0000-0002-2742-9021; https://orcid.org/0000-0001-8120-7123; 30950447; AAC-5654-2020; V-5717-2017; HOC-5611-2023; AAG-2213-2021BACKGROUND: To compare the efficacies of standard dose-(SDRT) and escalated dose radiotherapy (EDRT) in newly diagnosed glioblastoma (GBM) with concurrent and adjuvant temozolomide (TMZ). MATERIALS AND METHODS: Outcomes of 126 newly diagnosed GBM patients who received SDRT (60 Gy, 30 fractions) or EDRT (70 Gy, 30 fractions) with concurrent plus adjuvant TMZ were retrospectively analyzed. Both groups received concurrent TMZ (75 mg/m(2)) during the course of RT and at least one course of adjuvant TMZ (150-200 mg/m(2)), thereafter. Overall survival (OS) and local progression free survival (LPFS) constituted the primary and secondary endpoints, respectively. RESULTS: At median 14.2 months follow-up, 26 (20.6%) patients were alive. Median LPFS and OS were 9.2 [95% confidence interval (CI); 8.4-10.0] and 15.4 months (95% CI; 12.1-18.8), respectively, for the entire cohort. Although the median OS was numerically superior in the EDRT this difference could not reach statistical significance (22.0 vs. 14.9 months; P = 0.45), Likewise, LPFS was also (9.9 vs. 8.9 months; P = 0.89) not different between the two treatment groups. In multivariate analysis, better recursive partitioning analysis class (3-4 vs. 5; P = 0.044) and extensive surgery (gross total resection vs. subtotal resection/biopsy only; P = 0.021) were identified to associate significantly with superior OS times, irrespective of the RT protocol. CONCLUSIONS: Although the current median OS of 22 months of the EDRT group is promising, no statistically significant survival advantage for EDRT was observed even in the presence of TMZ. Randomized studies with larger population sizes and available genetic markers are warranted to conclude more reliably on the fate of EDRT plus TMZ.Item Oncological Outcomes For Encapsulated Papillary Carcinoma Of The Breast: Multicentric Study Of Turkish Society For Radiation Oncology Breast Cancer Study Group (TROD 06-014 Study)(2023) Gurdal, Necla; Yildirim, Berna Akkus; Gursel, Ozge Kandemir; Ozkurt, Selnur; Ibis, Kamuran; Gultekin, Melis; Tepetam, Huseyin; Gul, Sule Karabulut; Guzeloz, Zeliha; Oksuz, Didem Colpan; Cetin, Ilknur Alsan; Yalcin, Berrin; Duzova, Mursel; Kanyilmaz, Gul; Yavas, Guler; Ozsaran, Zeynep; 36464924BackgroundEncapsulated papillary carcinoma (EPC) is a rare malignant papillary breast cancer accounting for approximately .5%-2% of all breast tumors. The aim of this multicenter study was to evaluate clinicopathologic features of EPC in addition to oncological outcomes and radiotherapy (RT) details. MethodsFrom 10 different academic hospitals in Turkey, we obtained pathology reports of 80 patients with histologically confirmed EPC between 2005 and 2022. Demographic, diagnostic, and treatment data were collected from medical records, retrospectively. Local failure, distant progression, toxicity-adverse effects, overall survival (OS), and disease-free survival were evaluated, and survival analyzes were performed using the Kaplan-Meier method. ResultsEighty patients with the diagnosis of misspelled sorry (ECP) were retrospectively evaluated. The median age of the patients was 63 (range, 35-85). After a median follow-up of 48 (range; 6-206) months, local recurrence was observed in three patients (4%). Local recurrence was less common in the patients who received whole breast RT with a tumour bed boost (p = .025). There were not any distant metastasis or disease-related death. RT was applied to 61% of the cases, and no treatment-related grade 3 or higher toxicity was reported in any of the patients. Five year OS, cancer-specific survival (CSS), and were observed as 85%, 100%, and 96%, respectively. ConclusionsECP is a rare, slow-progressing breast carcinoma associated with good prognosis, it is a disease of elderly patient, and usually occurs in postmenopausal women. It responds extremely well to optimal local treatments and appropriate adjuvant treatments on a patient basis, and has excellent OS and CSS ratios.Item Contralateral Humerus Avascular Necrosis Diagnosed Immediately after Radiotherapy in a Patient with Breast Cancer(2022) Analan, P. D.Radiotherapy (RT) is an important component of treatment for malignant tumours, and avascular necrosis (AVN), which is often associated with high morbidity and disability, frequently accompanies this type of therapy. It generally develops in the same extremity with the treated region and may continue long after the treatment is completed. Early identification of AVN has the potential to reduce morbidity and improve the patient's quality of life. Herein, we present a case of contralateral humerus avascular necrosis diagnosed immediately after the first round of RT in a patient with breast cancer.Item Uterine papillary serous and clear cell carcinomas: Comparison of characteristics and clinical outcomes(2022) Sari, Sezin Yuce; Guler, Ozan Cem; Oymak, Ezgi; Gultekin, Melis; Yigit, Ecem; Kahvecioglu, Alper; Yuce, Kunter; Celik, Husnu; Usubutun, Alp; Bolat, Filiz; Onal, Cem; Yildiz, Ferah; 0000-0003-1185-9227; 35385171Introduction To assess the rate of disease control and survival after adjuvant treatment in patients with uterine papillary serous (PSC) and clear cell carcinoma (CCC) and compare the results between these two subtypes. Methods The medical charts of 199 patients with de novo uterine PSC or CCC who underwent radiotherapy (RT) following surgery between 2001 and 2019 in three radiation oncology departments were retrospectively evaluated. Adjuvant treatment was decided by a multidisciplinary tumor board. All patients were planned to undergo adjuvant 4-6 cycles of chemotherapy with external beam RT (EBRT) and/or vaginal brachytherapy (VBT). Results Median age was 63 years for all, 64 years for PSC, and 59 years for CCC, respectively. Complete surgical staging was applied in 98% of patients. Histopathologic subtype was PSC in 142 (71%) and pure CCC in 57 (29%) patients, respectively. FIGO stage was I in 107 (54%), II in 35 (18%), and III in 57 (28%) patients, respectively. Lympho-vascular space invasion and positive peritoneal cytology (PPC) were present in 42% and 10% of patients, respectively. All patients but 23 (12%) underwent adjuvant chemotherapy. Median follow-up was 49.5 months for all patients, 43.9 months for patients with PSC, and 90.4 months for patients with CCC, respectively. During follow-up, 20 (10%) patients developed pelvic recurrence (PR) and 37 (19%) developed distant metastasis (DM). PSC subtype increased the PR and DM rates, although the latter not statistically significant. The 5-year overall survival and disease-free survival rate was 73% and 69% for all patients, 71% and 66% for patients with PSC, and 77% and 75% for patients with CCC, respectively. The difference was more prominent in patients with stage >= IB disease. In multivariate analysis, advanced age and PPC significantly decreased all survival rates. Conclusion PSC has a worse prognosis than CCC with regard to pelvic and distant recurrence with a trend for decreased survival rates. Therefore, a more aggressive therapy is needed for patients with uterine PSC, particularly in patients with stage >= IB disease.Item Effects of Adipose-Derived Stem Cells and Platelet-Rich Plasma for Prevention of Alopecia and Other Skin Complications of Radiotherapy(2021) Evin, Nuh; Tosun, Zekeriya; Aktan, Tahsin Murad; Duman, Selcuk; Harmankaya, Ismail; Yavas, Guler; 33141771Background Radiotherapy (RT) involves the use of ionizing radiation in treating malignancies and benign disorders. However, RT damages target and healthy surrounding tissues in a dose-dependent manner. This effectively reduces patient compliance and quality of life, thereby warranting the prevention of RT-induced adverse effects on skin. Adipose-derived stem cells (ASCs) are used to treat RT-induced damage and platelet-rich plasma (PRP) provides a scaffold that potentiates the effects of ASCs. Thus, the aim of this study was to determine the mechanism employed by ASCs and PRP in protecting against RT-induced adverse effects. Methods We have established an immunodeficient mouse transplantation model using which human hair follicular units were implanted. When the follicular units were macroscopically and microscopically mature and anagenic, we administered localized RT. Subsequently, the mice were randomly divided into 4 groups based on the subcutaneous injection of the following to the irradiated transplantation site: saline, PRP, ASCs, and a combination of ASCs and PRP. Next, we used macroscopic and microscopic analyses to determine the protective effects of the injected solutions on skin and hair follicles. Results Adipose-derived stem cells reduced RT-induced adverse effects, such as impaired wound healing, alopecia, skin atrophy, and fibrosis by suppressing inflammation, dystrophy, degeneration, connective tissue synthesis, and apoptosis and increasing cellular proliferation, differentiation, and signaling. Moreover, these effects were augmented by PRP. Conclusions Thus, co-administering ASCs with PRP in mice prevented RT-induced adverse effects and can be tested for use in clinical practice.Item Oligometastatic Bone Disease in Castration-Sensitive Prostate Cancer Patients Treated With Stereotactic Body Radiotherapy Using Ga-68-PSMA PET/CT TROD 09-004 Study(2021) Onal, Cem; Ozyigit, Gokhan; Akgun, Zuleyha; Atalar, Banu; Igdem, Sefik; Oymak, Ezgi; Agaoglu, Fulya; Selek, Ugur; Guler, Ozan Cem; Hurmuz, Pervin; 33661210Purpose To evaluate the outcomes of metastasis-directed treatment (MDT) using stereotactic body radiotherapy (SBRT) for bone-only oligometastasis (OM) detected with gallium prostate-specific membrane antigen (Ga-68-PSMA) PET/CT in castration-sensitive prostate cancer (PC) patients. Methods In this multi-institutional study, clinical data of 74 PC patients with 153 bone lesions who were undergoing MDT were retrospectively evaluated. Twenty-seven patients (36.5%) had synchronous, and 47 (63.5%) had metachronous OM. All patients had PC with 5 metastases or fewer detected by Ga-68-PSMA PET/CT and treated using SBRT with a median dose of 20 Gy. The prognostic factors for PC-specific survival (PCSS) and progression-free survival (PFS) were analyzed. Results The median follow-up was 27.3 months. Patients with synchronous OM were older and received higher rates of androgen deprivation therapy after SBRT compared with patients with metachronous OM. The 2-year PCSS and PFS rates were 92.0% and 72.0%, respectively. A prostate-specific antigen (PSA) decline was observed in 56 patients (75.7%), and 48 (64.9%) had a PSA response defined as at least 25% decrease of PSA after MDT. The 2-year local control rate per lesion was 95.4%. In multivariate analysis, single OM and PSA response after MDT were significant predictors for better PCSS and PFS. In-field recurrence was observed in 4 patients (6.5%) with 10 lesions at a median of 13.1 months after MDT completion. No serious late toxicity was observed. Conclusions We demonstrated that SBRT is an efficient and well-tolerated treatment option for PC patients with 5 bone-only oligometastases or fewer detected with Ga-68-PSMA PET/CT.Item Impact of lymph node ratio in patients with stage IIIC endometrial carcinoma treated with postoperative radiotherapy(2021) Onal, Cem; Sari, Sezin Yuce; Yavas, Guler; Guler, Ozan Cem; Yiğit, Ecem; Oymak, Ezgi; Gultekin, Melis; Yildiz, Ferah; 0000-0002-2742-9021; 34355983; D-5195-2014Aim: To evaluate the prognostic value of the lymph node ratio (LNR) and other clinicopathological factors in patients with stage IIIC endometrial cancer. Methods: Factors affecting overall survival (OS) and progression-free survival (PFS) were assessed in 397 patients with stage IIIC endometrial cancer treated with postoperative radiotherapy. Patients undergoing the removal of at least ten lymph nodes were included in the study. Results: The 5-year OS and PFS rates were 58% and 52%, respectively, with a median follow-up time of 35.7 months. The LNR cutoff value was 9.6%. In the multivariate analysis, advanced age (>= 60 years), grade III tumor, presence of cervical stromal invasion, higher LNR and lack of adjuvant chemotherapy were independent predictors for worse OS and PFS. Conclusion: The LNR is an independent predictor for OS and PFS in patients with stage IIIC endometrial cancer treated with postoperative radiotherapy.
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