Browsing by Author "Cengiz, Mustafa"

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Outcome of Elderly Nasopharyngeal Carcinoma Patients: A Single Center Study
(2020) Basaran, Hamit; Cengiz, Mustafa; Yazici, Gozde; Ozdemir, Yurday; Suslu, Nilda; Gullu, Ibrahim H.; Ozyigit, Gokhan; 0000-0002-2218-2074; AAG-5629-2021
Objective: This study aimed to assess the efficiency of radiotherapy and evaluate its outcomes for elderly (> 65 years) patients who have undergone treatment for nasopharyngeal carcinoma (NPC). Methods: Forty- five (male, 35; female, 10) elderly patients with a diagnosis of undifferentiated NPC who were treated at our institution between 1994 and 2012 were retrospectively evaluated. The primary endpoint was the relationship between the patients' characteristics and overall survival (OS); progression-free survival (PFS), locoregional progression-free survival (LR-PFS), and toxicity analysis were the secondary endpoints. Results: The patients had a median age of 74.2 years. At a median follow-up period of 64 months, the median OS, PFS, and LR-PFS were 45 (95% confidence interval [CI]: 5.887-84.113), 34 (95% CI: 0.0-70.504), and 45 (95% CI: 20.092-69908) months, respectively. The 2-, 3-, and 5-year OS rates were 61.5%, 53.1%, and 50.0%, respectively, and the 2-, 3-, and 5-year PFS rates were 57.6%, 46.8%, and 43.7%, respectively. Patients with T stage (T3-T4 vs.T1-T2) or N stage (N0-1 vs. N2) had significantly shorter OS (p<0.05), PFS (p<0.05), and LR-PFS (p<0.05) outcomes, respectively, which were also confirmed using a multivariate analysis (p<0.05). Conclusion: Our results demonstrated that the established prognostic factors, including T and N stages, were important prognostic indicators of NPC in elderly patients
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.
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-5717-2017
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.