Murat Gurkaynak
Hacettepe University
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International Journal of Radiation Oncology Biology Physics | 2011
Mustafa Cengiz; Gokhan Ozyigit; Gozde Yazici; A. Dogan; Ferah Yildiz; Faruk Zorlu; Murat Gurkaynak; Ibrahim Gullu; Sefik Hosal; Fadil Akyol
PURPOSE In this study, we present our results of reirradiation of locally recurrent head-and-neck cancer with image-guided, fractionated, frameless stereotactic body radiotherapy technique. METHODS AND MATERIALS From July 2007 to February 2009, 46 patients were treated using the CyberKnife (Accuray, Sunnyvale, CA) at the Department of Radiation Oncology, Hacettepe University, Ankara, Turkey. All patients had recurrent, unresectable, and previously irradiated head-and-neck cancer. The most prominent site was the nasopharynx (32.6%), and the most common histopathology was epidermoid carcinoma. The planning target volume was defined as the gross tumor volume identified on magnetic resonance imaging and computed tomography. There were 22 female and 24 male patients. Median age was 53 years (range, 19-87 years). The median tumor dose with stereotactic body radiotherapy was 30 Gy (range, 18-35 Gy) in a median of five (range, one to five) fractions. RESULTS Of 37 patients whose response to therapy was evaluated, 10 patients (27%) had complete tumor regression, 11 (29.8%) had partial response, and 10 (27%) had stable disease. Ultimate local disease control was achieved in 31 patients (83.8%). The overall survival was 11.93 months in median (ranged, 11.4-17.4 months), and the median progression free survival was 10.5 months. One-year progression-free survival and overall survival were 41% and 46%, respectively. Grade II or greater long-term complications were observed in 6 (13.3%) patients. On follow-up, 8 (17.3%) patients had carotid blow-out syndrome, and 7 (15.2%) patients died of bleeding from carotid arteries. We discovered that this fatal syndrome occurred only in patients with tumor surrounding carotid arteries and carotid arteries receiving all prescribed dose. CONCLUSIONS Stereotactic body radiotherapy is an appealing treatment option for patients with recurrent head-and-neck cancer previously treated with radiation to high doses. Good local control with considerable 1-year survival is achieved with a relatively high rate of morbidity and related mortality.
Neurological Sciences | 2000
Faruk Zorlu; Murat Gurkaynak; Ferah Yildiz; Kamil Öge; I. Lale Atahan
Abstract Cranial chordomas are uncommon tumors accounting for less than 1% of all intracranial neoplasms. Although they are slowly growing, rarely metastasising tumors, cranial chordomas are challenging to treat due to their critical location, invasive nature and aggressive recurrence. The aim of this retrospective study was to evaluate the role of conventional irradiation in the treatment of clival chordomas with overt residual disease after incomplete surgery.Between January 1979 and December 1997, 18 patients with histologically confirmed clival chordoma were treated with radiotherapy. Median age at the time of diagnosis was 32 years. The mean duration of the symptoms before diagnosis was 33.9 months. Median tumor diameter at initial presentation was 5 cm (range, 3–7 cm). The type of surgical procedure was subtotal excision in 11 patients and biopsy in 7. Radiation treatment was delivered with megavoltage units, and total doses between 50 Gy and 64 Gy (median, 60 Gy) were administered with conventional daily fractions. One patient received additional 12.50 Gy with linear accelerator-based stereotactic radiosurgery after subtotal excision and external irradiation.The mean follow-up time was 43.2 months. Overall survival at 5 years was 35%. Eleven patients showed progression after radiotherapy. The median time to progression after radiotherapy was 40.8 months (38.4–43.2) with a 5-year progression-free survival of 23%. Five patients (29.4%) showed symptomatic relief after radiotherapy while persistent symptoms were recorded for 6 patients. Incomplete surgery and conventional external radiotherapy with a dose of around 60 Gy seem to be inadequate in the treatment of clival chordomas.
International Journal of Radiation Oncology Biology Physics | 2011
Gokhan Ozyigit; Mustafa Cengiz; Gozde Yazici; Ferah Yildiz; Murat Gurkaynak; Faruk Zorlu; Demet Yildiz; Sefik Hosal; Ibrahim Gullu; Fadil Akyol
PURPOSE We assessed therapeutic outcomes of reirradiation with robotic stereotactic radiotherapy (SBRT) for locally recurrent nasopharyngeal carcinoma (LRNPC) patients and compared those results with three-dimensional conformal radiotherapy (CRT) with or without brachytherapy (BRT). METHODS AND MATERIALS Treatment outcomes were evaluated retrospectively in 51 LRNPC patients receiving either robotic SBRT (24 patients) or CRT with or without BRT (27 patients) in our department. CRT was delivered with a 6-MV linear accelerator, and a median total reirradiation dose of 57 Gy in 2 Gy/day was given. Robotic SBRT was delivered with CyberKnife (Accuray, Sunnyvale, CA). Patients in the SBRT arm received 30 Gy over 5 consecutive days. We calculated actuarial local control and cancer-specific survival rates for the comparison of treatment outcomes in SBRT and CRT arms. The Common Terminology Criteria for Adverse Events v3.0 was used for toxicity evaluation. RESULTS The median follow-up was 24 months for all patients. Two-year actuarial local control rates were 82% and 80% for SBRT and CRT arms, respectively (p = 0.6). Two-year cancer-specific survival rates were 64% and 47% for the SBRT and CRT arms, respectively (p = 0.4). Serious late toxicities (Grade 3 and above) were observed in 21% of patients in the SBRT arm, whereas 48% of patients had serious toxicity in the CRT arm (p = 0.04). Fatal complications occurred in three patients (12.5%) of the SBRT arm, and four patients (14.8%) of the CRT arm (p = 0.8). T stage at recurrence was the only independent predictor for local control and survival. CONCLUSION Our robotic SBRT protocol seems to be feasible and less toxic in terms of late effects compared with CRT arm for the reirradiation of LRNPC patients.
Acta Oncologica | 2008
I.L. Atahan; Ferah Yildiz; Gokhan Ozyigit; Sait Sari; Murat Gurkaynak; Ugur Selek; Mutlu Hayran
Purpose. We retrospectively evaluated the impact of percent positive axillary nodal involvement on the therapeutic outcomes in patients with non-metastatic breast cancer receiving postmastectomy radiotherapy and chemotherapy. Materials and methods. Between January 1994 and December 2002, the medical records of 939 eligible non metastatic breast carcinoma patients were analyzed. Chest wall radiotherapy was indicated in case of positive surgical margin, tumor size equal or more than 4 cm, skin-fascia invasion. Lymphatic irradiation was applied for more than three metastatic axillary lymph nodes, incomplete axillary dissection (<10 lymph nodes), extracapsular extension or perinodal fat tissue invasion. A total dose of 50 Gy was given to chest wall and lymph node regions with 2 Gy daily fractions. Statistical analyses were performed by Kaplan-Meier method, Log-rank test and Coxs regression analysis. Results. The median follow-up for all patients alive was 62 months. The 5-year overall survival (OS) and disease-free survival (DFS) for entire cohort were 81%, and 65%, respectively. Univariate analysis for OS revealed significance for tumour size (≤5 cm vs. >5cm, p<0.001), metastatic nodal involvement (0 vs. 1–3 vs. >4 LN, p<0.001), percent positive nodal involvement ([metastatic nodes/total nodes removed]×100; 0 vs.≤25% vs. 26–50% vs. >50%, p<0.001), surgical margin status (negative vs. positive, p=0.05), and hormonal treatment (present vs. absent, p=0.03). DFS had similarly significance for age (≤40 years vs. >40 years, p=0.006), tumour size (0.02), metastatic nodal involvement (p<0.001), percent positive nodal involvement (p<0.001), and perinodal invasion (present vs. absent, p=0.01). Multivariate analysis revealed significance for tumour size, percent positive nodal involvement, hormonal treatment, and surgical margin status for OS. Age and percent positive nodal involvement were found to be significant for DFS. Conclusion. Percent positive nodal involvement was found to be a significant prognostic factor for survival in all end-points.
American Journal of Clinical Oncology | 2003
Murat Gurkaynak; Mustafa Cengiz; Serap Akyurek; Enis Özyar; I.L. Atahan; Gülten Tekuzman
Optimal management of patients with localized Waldeyer’s ring (WR) lymphoma remains controversial due to the lack of randomized studies and heterogenous grouping of most reported series. In this retrospective study, we have evaluated the possible prognostic factors and treatment outcome of WR non-Hodgkin’s lymphoma. Between December 1993 and February 2000, 32 patients with WR lymphoma, stage I (11 patients) and stage II (21 patients) were treated. There were 17 male patients and 15 female patients with a median age of 47 years. The distribution among different anatomical sites were as follows: tonsils in 16 (50%), nasopharynx in 10 (31%), base of tongue in 6 (19%). According to Working Formulation, 10 had high-grade, 17 intermediate grade, 3 low-grade, and 2 had unclassified lymphomas. Combined chemotherapy and radiotherapy was the primary modality of therapy for intermediate or high-grade lymphoma. Radiotherapy alone was employed only in low-grade WR lymphomas. Chemotherapy was median 6 courses of CHOP (cyclophosphamide, doxorubicin (Adriamycin), vincristine, and prednisolone) in 26 patients and CEOP (cyclophosphamide, doxorubicin, etoposide, and prednisone). Radiotherapy volume was involved field and the median dose was 40 Gy. Median follow-up is 40 months (ranged from 6–82 months). Overall survival and disease-free survival (DFS) rates at 3 years are 100% and 92%, respectively. Two patients developed recurrence, both salvaged with further chemotherapy. Only one patient died because of other reasons. International Prognostic Index score (≤2 vs. >2) is found to be an important prognostic factor for DFS. The other significant prognostic factors for DFS are performance status and serum levels of alkaline phosphatase and lactate dehydrogenase. Our results suggest that combined chemotherapy and involved field radiotherapy is appropriate treatment for stage I-II WR lymphoma. International Prognostic Index is the strongest predictor for DFS.
Head and Neck-journal for The Sciences and Specialties of The Head and Neck | 2013
Gokhan Ozyigit; Mustafa Cengiz; Gozde Yazici; Ferah Yildiz; Duygu Sezen; Demet Yildiz; Murat Gurkaynak; Faruk Zorlu; Fadil Akyol
Sinonasal mucosal melanoma (SNMM) is a rare entity originating from melanocytes of the sinonasal mucosa. Postoperative radiotherapy is recommended in all cases to increase local control. However, external radiotherapy is rarely used as a definitive treatment modality. In this report, we present 4 cases of SNMM treated with CyberKnife (Accuray, Sunnyvale, CA).
Strahlentherapie Und Onkologie | 2007
Ugur Selek; Faruk Zorlu; Pervin Hurmuz; Mustafa Cengiz; Alev Turker; Figen Soylemezoglu; Murat Gurkaynak
Purpose:To evaluate the outcome and prognostic factors of adult patients with medulloblastoma.Patients and Methods:26 adult medulloblastoma patients with a median age of 27 were subjected to craniospinal radiotherapy. A dose of 30.6 Gy with 1.8 Gy/fraction/day was prescribed to M0 patients, while 36 Gy were to be applied in patients with positive cerebrospinal liquor findings. The posterior fossa was boosted to 54 Gy. While 20 patients underwent external-beam radiotheray alone, only six received sequential adjuvant chemotherapy.Results:Male/female ratio was 1.2. Preradiotherapy Karnofsky performance status was recorded as median 100%. 50% were classified as poor risk (n = 10, subtotal resection; n = 3, M+). The median follow-up time was 46.5 months. The 5-year actuarial survival rates for recurrence-free, distant metastasis-free, disease-free, and overall survival were 82.5%, 90.8%, 73.5%, and 89.7%, respectively. Patient characteristics, treatment factors and tumor characteristics failed to show any significance in univariate analysis. Grade 3 or 4 late morbidities were not observed.Conclusion:Yet, the current standard of care seems to remain craniospinal irradiation after maximal surgical resection of the primary neoplasm without clear indications for adjuvant chemotherapy.Ziel:Evaluation der Ergebnisse und Prognosefaktoren bei erwachsenen Patienten mit Medulloblastom.Patienten und Methodik:Insgesamt 26 erwachsene Patienten mit Medulloblastom (medianes Alter 27 Jahre) wurden kraniospinal bestrahlt. Dabei erhielten M0-Patienten eine Gesamtdosis von 30,6 Gy in Einzelfraktionen von 1,8 Gy/Tag, und bei Patienten mit einem positiven Liquorbefund wurden insgesamt 36 Gy appliziert. Die hintere Schädelgrube wurde bis zu einer Gesamtdosis von 54 Gy geboostet. 20 Patienten erhielten eine alleinige postoperative Bestrahlung, sechs Patienten eine sequentielle adjuvante Chemotherapie.Ergebnisse:Das Verhältnis von Männern zu Frauen lag bei 1,2. Der vor der Strahlentherapie bestehende mediane Karnofsky-Index betrug 100%. 50% der Patienten wurden als Hochrisikopatienten eingestuft (subtotale Resektion: n = 10, M+: n = 3). Die mediane Nachbeobachtungszeit betrug 46,5 Monate. Die Überlebensraten nach 5 Jahren für das rezidivfreie Überleben, das metastasenfreie Überleben, das krankheitsfreie Überleben und das Gesamtüberleben lagen bei 82,5%, 90,8%, 73,5% und 89,7%. Es fanden sich keine signifikanten Prognosefaktoren in der univariaten Analyse. Spättoxizitäten des Grades 3 oder 4 wurden ebenfalls nicht beobachtet.Schlussfolgerung:Die Standardbehandlung von Patienten mit einem Medulloblastom im Erwachsenenalter bleibt die kraniospinale Bestrahlung nach maximaler chirurgischer Resektion, ohne klare Indikation für eine adjuvante Chemotherapie.
International Journal of Radiation Oncology Biology Physics | 1999
Mustafa Cengiz; Murat Gurkaynak; I. Lale Atahan; Kamer Kilic; Yüksel Totan
PURPOSE Cataract is an unavoidable complication when radiation therapy includes the lens, even in small doses. Alterations in the ion content of the lens were considered to play an essential role in cataract formation. In this experimental study, the effect of verapamil on ion concentrations within the irradiated lenses was investigated in rats. METHODS AND MATERIALS Forty female Wistar albino rats, each weighing 180-250 g, were divided into three groups: (a) radiation treated (n = 10); (b) no treatment (n = 10); (c) or a combination of radiation and verapamil (n = 20). Both the radiation group and verapamil-treated group received 5 Gy radiation to the cranium in a single fraction, including the eyes, within the irradiation volume. All animals were sacrificed by bleeding, 7.5 weeks posttreatment. Calcium, sodium, and potassium levels were measured in blood and in lens homogenates. However, for technical reasons, magnesium levels could only be studied in lens homogenates. RESULTS Potassium and sodium concentrations in lens homogenates did not differ in the control and radiation groups, but both were significantly lower in the verapamil-treated group (p = 0.001, p = 0.009, respectively). Calcium levels were higher in the radiation group and lower in the verapamil-treated group compared to the controls (p < 0.0001); magnesium levels did not differ (p = 0.37). CONCLUSION Verapamil effectively decreased the lens calcium concentration, which is accepted as the key element in radiation cataractogenesis. It is therefore concluded that verapamil may reduce the risk of radiation-induced cataract formation.
Radiotherapy and Oncology | 1992
Fadil Akyol; I. Lale Atahan; Faruk Zorlu; Murat Gurkaynak; Hilmi F. Alanyali; Enis Özyar
43 Patients with the diagnosis of cerebellar astrocytoma were post-operatively treated, between 1 January 1976 and 31 December 1985. Their age ranged between 2 and 51 years with a median of 13. There were 22 males and 21 females. The tumours were reported as grade I in 18, and grade II in 25 patients. The primary surgical intervention was in the form of biopsy in 3, subtotal excision in 24 and macroscopic total excision in 16. All patients were treated with cobalt-60 teletherapy unit, to a total tumour dose of 4500-5500 cGy in 6-7 weeks. The obtained 5 and 10 year actuarial survival rates are 78% and 78%. Our study gives the impression that, age, sex and tumour grade are not determining factors in survival and post-operative radiotherapy improves prognosis in cases treated by subtotal excision while it remains unnecessary in those who had undergone total surgical removal.
British Journal of Radiology | 1989
Atahan Il; Fadil Akyol; Zorlu F; Murat Gurkaynak
Aggressive fibromatosis is a rare, slowly growing benign tumour arising from the fascial sheaths and musculoaponeurotic structures (Greenberg et al, 1981; Leibel et al, 1983). Its incidence is reported to be 25 in 100 000 (Greenberg et al, 1981; Leibel et al, 1983). This locally aggressive, non-encapsulated tumour is formed by the proliferation of benign fibroblasts. It extends along the fascial planes and infiltrates the adjacent muscles. Depending on its localization, it may cause erosion of the underlying or neighbouring bones and pressure on the blood vessels, nerves and air passages with related symptoms and restriction of movements of the extremities (Leibel et al, 1983; Raney et al, 1987). Distant organ and lymphatic metastases are very rarely encountered. The incidence of local recurrence following surgical excision varies between 40 and 50%, thus making radical surgical intervention an alternative treatment procedure (Suit & Russel, 1975). In 1928, Ewing was the first to propose radiotherapy as a...