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Öğe Acute histopathological responses of testicular tissues after different fractionated abdominal irradiation in rats(Informa Healthcare, 2015) Akdere, Hakan; Caloglu, Vuslat Yurut; Tastekin, Ebru; Caloglu, Murat; Turkkan, Gorkem; Mericliler, Meric; Burgazli, Kamil MehmetPurpose: To compare the effects of different fractionated doses of abdominal radiation therapy on acute histopathological responses of testicular tissues in rats. Methods: Thirty-three 3-week-old Wistar albino rats were randomized into 6 groups: group 1 (n = 5), control; group 2 (n = 4), hypofractionated total abdominal irradiation (TAI) of 6 Gy/1 fraction/day for 2 days; group 3 (n = 6), hypofractionated TAI of 4 Gy/1 fraction/day for 3 days; group 4 (n = 6), hypofractionated TAI of 3 Gy/1 fraction/day for 4 days; group 5 (n = 6), conventionally fractionated TAI of 2 Gy/1 fraction/day for 6 days; group 6 (n = 6), conventionally fractionated TAI of 1.7 Gy/1 fraction/day for 7 days. Mean epithelial length and diameter of seminiferous tubules of testicular tissues were determined after euthanasia. Results: Initially, a highly significant decrease in both the mean tubular diameter and epithelial height of the seminiferous tubules was demonstrated in all irradiated rats compared with the control group. No significant differences regarding both damage parameters were found between different hypofractionated radiation therapies. Both conventional radiation therapies reduced the epithelial height and mean diameter of the seminiferous tubules to a lesser extent when compared with 6 Gy/1 fraction/day hypofractionated therapy. It was further shown that parameter values were comparable between rats that received 3 Gy/day hypofractionated therapy and rats that received either of the two conventional therapies. Furthermore, although 4 Gy/day hypofractionation decreased tubular diameter and epithelial length to a greater degree compared with the conventional therapy of 1.7 Gy/1 fraction/day, no statistically significant difference was found when compared with conventional therapy of 2 Gy/1 fraction/day. Additionally, no statistically significant difference was demonstrated between the two types of conventional radiotherapy application. Conclusion: The present study demonstrated that hypofractionated abdominal irradiation leads to more prominent tissue damage in the testes than conventional irradiation.Öğe Bicalutamide-associated hallucinations in a metastatic prostate cancer patient: A case report(Sage Publications Ltd, 2020) Turkkan, Gorkem; Dogan, Caner; Tek, BurakIntroduction Bicalutamide is widely used in the treatment of prostate cancer. Among its side effects, central nervous system disorders are relatively rare, and the information about bicalutamide-associated hallucinations is limited. Case report We report an uncommon case of a patient with metastatic prostate cancer, who had hallucinations due to the use of bicalutamide. Management and outcome The patient accepted to receive only hormonal therapy (bicalutamide and leuprolide acetate). But he developed hallucinations due to bicalutamide use. His hallucinations disappeared after discontinuation of bicalutamide. A good response was obtained with the use of luteinizing hormone-releasing hormone agonist monotherapy. Discussion The pathophysiology of bicalutamide-induced hallucinations is unclear. We hypothesize that antiandrogens can indirectly cause hallucinations through changes in plasma testosterone and cerebral reelin expression. Additionally, luteinizing hormone-releasing hormone agonist monotherapy is a good option in metastatic prostate cancer patients who have intolerable side effects due to the use of antiandrogens.Öğe Evaluation of Risk Groups for the Prediction of Biochemical Progression in Patients Undergoing Radical Prostatectomy(Galenos Publ House, 2022) Madendere, Serdar; Turkkan, Gorkem; Arda, Ersan; Caloglu, Vuslat Yurut; Kuyumcuoglu, UgurObjective: The aim of this study was to investigate the potential relationship between biochemical progression and prognostic risk factors in patients with prostate cancer (PCa) patients undergoing radical prostatectomy (RP). Materials and Methods: After inclusion/exclusion criteria were applied, 216 patients who underwent RP were included in this study. Follow-up protocol included prostate specific antigen (PSA) measurements; every 3 months for the first year, every 6 months for the second year, and an annual check after 2 years. Preoperative and postoperative PSA measurements, pathological stage, Gleason score (GS), extraprostatic extension, positive surgical margins and seminal vesicle invasion were evaluated. Uni- and multivariable analyses were used to detect the relationship between biochemical progression, biochemical progression-free survival (BPFS) and prognostic risk factors. Results: Median follow-up was 29 months. Biochemical progression was observed in 39 (18.1%) patients, in 18 (9.7%) of 185 patients with first postoperative PSA level of <0.2 ng/dL, and 21 (67.7%) of 31 patients with first postoperative PSA level of >= 0.2 ng/dL. Patients with first postoperative PSA level of >= 0.2 ng/dL had a statistically significant higher risk of biochemical progression and shorter BPFS (odds ratio: 2.41; 95% confidence interval: 1.84-3.10; p<0.001), in univariate and multivariate analyses. Patients with GS =8 or T3-4 or positive surgical margins had a statistically significant higher risk of biochemical progression (p<0.001, p=0.003, p<0.001). Conclusion: Postoperative PSA level higher than >= 0.2 ng/dL was the most important predictor of biochemical progression and BPFS after RP. GS >= 8, T3-4 stages, and positive surgical margins are also related to biochemical progression.Öğe Hemangiopericytoma at the Craniovertebral Junction: A Case Report(Kare Publ, 2019) Delen, Emre; Akinci, Ahmet Tolgay; Turkkan, Gorkem; Yalta, Tulin Deniz; Simsek, OsmanIntradural extra medullary hemangiopericytomas (HPCs) are extremely rare and a hemangiopericytoma located at the craniovertebral junction might present radiologic features similar to those of meningioma or schwannoma.To the best of our knowledge, this report is among a few reported cases of HPC at the craniovertebral junction. Although they are very rare, HPCs should kept in mind in the differential diagnosis of the intradural extramedullary lesion due to differences in treatment such as adjuvant radiotherapy.Öğe The importance of weight loss during definitive radiotherapy in patients with laryngeal carcinoma(Wolters Kluwer Medknow Publications, 2022) Yurut-Caloglu, Vuslat; Caloglu, Murat; Turkkan, GorkemBackground: The aim of this study is to determine the prognostic significance of weight loss (WL) on overall survival (OS) and progression-free survival (PFS) in patients with locally advanced unresectable laryngeal carcinoma undergoing definitive radiotherapy (RT) or chemo-RT (CRT) in a single institution. Patients and Methods: One hundred and thirty-two patients with newly diagnosed locally advanced laryngeal carcinoma were included in this study retrospectively. All patients were treated with definitive RT or CRT. The tumor and metastatic lymph nodes received 70 Gy. Subclinical disease (low-risk and high-risk area) was irradiated 50-60 Gy prophylactically. Unintentional WL >= 5% was defined as the critical level. Bodyweight was evaluated on the 1st day of RT and once a week during RT. Caloric needs were calculated as 25-30 kcal/kg/day. Results: Median follow-up was 17.8 months (range: 2.35-85 months). During treatment, there was a statistically significant WL in patients (P = 0.004). WL was >= 5% in 62 (47%) of the patients. There was a statistically significant relationship between WL and tumor differentiation (P = 0.004), completion of treatment (P = 0.004), WHO performance status (P < 0.0001), T stage (P = 0.003), N stage (P = 0.049), and supraglottic tumor location (P = 0.005). In the univariate analysis, WL, WHO performance status, T stage, N stage, tumor localization, and tumor differentiation, were seen to affect OS. Additionally, WL, WHO performance status, N stage, and tumor differentiation were prognostic factors for PFS. In the multivariate analysis, it was observed that only WL and WHO performance status were significant factors for both OS (P = 0.001, and P < 0.01) and PFS (P < 0.001, and P < 0.001), respectively. Three-year OS and PFS was 50.3% and 19.5% for patients with WL versus 77.8% and 49.0% for patients without WL. Conclusions: It is clear that WL has prognostic significance in patients who have undergone definitive RT or CRT due to locally advanced laryngeal carcinoma. In particular, it should be taken into consideration that patients with supraglottic tumor, lymph node involvement, and poor performance status are at greater risk for WL.Öğe Radiotherapy-induced Cardiotoxicity After the Treatment of Pulmonary and Mediastinal Solid Tumors(Kare Publ, 2022) Saynak, Mert; Turkkan, Gorkem; Nurlu, Dilek; Ozguven, YildirayThoracic tumors are extremely common and radiotherapy plays an important role in the treatment of these malignancies. Cardiac radiation exposure which is inevitable during thoracic radiotherapy may damage the heart muscle, valves, or coronary arteries. If a malignant thoracic disease can be successfully treated with the contribution of radiotherapy, long-term cardiac toxicity will become a critical factor in determining survival. Therefore, radiation oncologists have recently focused on efforts to provide local disease control without causing toxicity. Over time, advances in radiotherapy techniques have made it possible to significantly limit the dose of cardiac structures while effectively treating the thoracic tumor. Intensity-modulated radiotherapy techniques are beneficial in reducing the cardiac dose and therefore cardiac toxicity. Advanced particle radiotherapy applications such as proton therapy have the potential to improve tumor cell killing efficiency and reduce the risk of cardiac complications. Close and longterm cooperation between radiation oncologists and cardiologists is important in the follow-up of patients undergoing thoracic radiotherapy.Öğe Recurrent Intracranial Meningeal Hemangiopericytoma with an Isolated Bone Metastasis: A Case Report and Literature Review(Kare Publ, 2017) Turkkan, Gorkem; Caloglu, Murat; Usta, Ufuk; Yurut Caloglu, Vuslat; Saygi, Haci Mehmet; Uzal, CemIntracranial meningeal hemangiopericytoma is a rare vascular tumor with a high rate of both local recurrence and the development of distant metastases. The aim of this report is to present the first case of recurrent meningeal hemangiopericytoma with an isolated femur metastasis and discuss the clinical features and treatment of this rare tumor. A 46-year-old woman was admitted with the complaint of sudden loss of consciousness and subsequently underwent an urgent craniotomy with total excision of the lesion. The diagnosis was meningeal hemangiopericytoma. The patient presented with a painful left hip 5 1/2 years after the initial surgery for the primary tumor. A lytic lesion, which was 4x4.5 cm in diameter, was seen on an X-ray of the proximal left femur. The patient underwent lesion removal surgery and pathological diagnosis was compatible with meningeal hemangiopericytoma. At 69th month, no progression has been observed in follow-up. Long-term follow-up is mandatory for meningeal hemangiopericytoma due to high recurrence rate many years after diagnosis. Further multi-institutional studies are strongly needed to understand the clinical behavior and treatment modalities of this rare disease.Öğe Recurrent Merkel cell carcinoma of the gluteal region: A case report(Wiley, 2019) Turkkan, Gorkem; Agdogan, Ozgur; Saynak, Mert; Uygun, Arzu C.; Ustun, FundaMerkel cell carcinoma (MCC) is a rare malignant tumor of the skin. The development of MCC on non-sun-exposed skin is extremely rare, with few cases reported in the literature. The present authors aimed to highlight the characteristic features and treatment options of this tumor. The present authors present a 50-year-old man who developed MCC on the left gluteal region (non-sun-exposed skin). After surgery with clear margins, adjuvant radiotherapy was given. Three months after radiotherapy, lymphatic recurrence was observed and he was treated with chemotherapy. On follow-up, systemic metastases were found and palliative treatment was planned.Öğe Survivin expression, HPV positivity and microvessel density in oropharyngeal carcinomas and relationship with survival time(Termedia Publishing House Ltd, 2017) Tastekin, Ebru; Caloglu, Vuslat Yurut; Durankus, Nilufer Kilic; Sut, Necdet; Turkkan, Gorkem; Can, Nuray; Puyan, Fulya OzIntroduction: Among head and neck cancers, those of the oral cavity and oropharynx are the second most prevalent following the larynx. This study aimed to research immunohistochemical expression of survivin, HPV positivity and microvessel density in tumors and their relationships with prognosis. Material and methods: Pathological materials and demographic properties of 46 patients were retrospectively evaluated. Survivin, HPV and CD34 (for microvessel density evaluation) antibodies were applied tumoral tissues. Survival times, clinical stage and differentiation were evaluated. Results: In univariate analysis, we observed that survivin, microvessel density and stage were significantly associated with survival time (p < 0.05). In multivariate analysis, only survivin and microvessel density were associated with survival time (p < 0.05). But we did not find significant correlation between neither tumor differentiation nor HPV positivity and survival (p > 0.05). Conclusions: Survivin levels and microvessel density were found to be effective prognostic factors and were related to survival in oral cavity and oropharyngeal cancers. Treatments targeting survivin expression and angiogenesis might be employed against these tumor groups.
