Ahmet Çakmak
Ankara University
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Featured researches published by Ahmet Çakmak.
Oral Oncology | 2000
D. Etiz; H.Ş. Erkal; Meltem Serin; B. Küçük; A. Heparı; Atilla Halil Elhan; Ö. Tulunay; Ahmet Çakmak
Forty-four patients with head and neck malignancies were included in a prospective, randomized, double-blind, placebo-controlled study for evaluation of sucralfate in prevention of oral mucositis induced by radiation therapy. Patients were randomized to receive oral suspensions of either sucralfate (n = 23) or placebo (n = 21) in six daily doses of 1 g. The primary tumors were treated with portals covering at least one-third of the oral mucosa to a minimum dose of 60 Gy. Drug therapy was not associated with significant adverse effects and compliance was satisfactory. Daily inspection of the oral mucosa and questionnaires for oral mucositis-related items demonstrated reduction in oral mucositis scores and oral pain scores and biopsies obtained from the buccal mucosa demonstrated reduction in evidence of altered vascular calibration, altered vascular permeability and leukocyte emigration with sucralfate. Clinical and histopathological demonstration of reduction in oral mucositis with sucralfate suggests that sucralfate might be recommended in the prevention of oral mucositis induced by radiation therapy in patients with head and neck malignancies.
Radiotherapy and Oncology | 1997
Haldun SiikrC Erkal; Meltem Serin; Ahmet Çakmak
BACKGROUND AND PURPOSE Optic pathway and chiasmatic-hypothalamic gliomas are rare childhood tumors. This study presents the experience in management of these tumors with radiation therapy. MATERIALS AND METHODS Thirty-three children with the diagnosis of optic pathway and chiasmatic-hypothalamic gliomas were treated with radiation therapy from 1973 through 1994 in the Department of Radiation Oncology at Ankara University Faculty of Medicine. Twenty-four children had optic pathway gliomas and nine had chiasmatic-hypothalamic gliomas. Evidence of neurofibromatosis was present in six children. Subtotal resection was performed in 22 children and a biopsy in seven. The most common prescription for total tumor dose was 50 Gy, delivered in 2 Gy daily fractions. Follow-up ranged from 0.5 to 16.1 years (mean, 13.6 years). RESULTS Overall, progression-free and cause-specific survival probabilities for the entire group were 93%, 82% and 93%, respectively, at 5 years and 79%, 77% and 88%, respectively, at 10 years. Differences in overall, progression-free and cause-specific survival probabilities between optic pathway and chiasmatic-hypothalamic gliomas were not statistically significant. Absence of evidence of neurofibromatosis correlated with significantly better progression-free and cause-specific survival probabilities. CONCLUSION Radiation therapy is effective in stabilization or improvement of vision and prevention of tumor progression in both optic pathway and chiasmatic-hypothalamic gliomas.
Radiotherapy and Oncology | 2001
Haldun Şükrü Erkal; Meltem Serin; Ahmet Çakmak
PURPOSE The present study reviews the experience in treatment of 447 patients with nasopharyngeal carcinomas, analyzing patient, tumor and treatment characteristics determining outcome. MATERIALS AND METHODS There were 322 males and 125 females, their ages ranging from 7 to 85 years (median, 45 years). Two-hundred and seventy-two patients had World Health Organization (WHO) type 3 carcinomas, 123 patients had T4 tumors and 320 patients had metastatic cervical lymph nodes. Three-hundred and eight patients were treated with radiation therapy alone and 139 patients with chemotherapy in combination with radiation therapy. Cumulative radiation dose to primary tumor ranged from 50 to 76Gy (median, 70Gy) and radiation dose to metastatic cervical lymph nodes ranged from 46 to 74Gy (median, 66Gy). RESULTS Follow-up ranged from 0.1 to 19.5 years (mean, 7.6 years). Local complete response was achieved in 357 patients. In multivariate analysis, T-classification, cumulative radiation dose to primary tumor and treatment with chemotherapy in combination with radiation therapy predicted local response. Nodal complete response was achieved in 272 patients. In multivariate analysis, N-classification and radiation dose to metastatic cervical lymph nodes predicted nodal response. Local failure was observed in 70 patients, nodal failure in 35 patients and systemic failure in 114 patients. Overall survival, disease-free survival and disease-specific survival were 33, 32 and 37%, respectively, at 10 years. In multivariate analysis, age, T-classification, N-classification, radiation dose and treatment with chemotherapy in combination with radiation therapy predicted overall survival whereas T-classification, N-classification, radiation dose and treatment with chemotherapy in combination with radiation therapy predicted both disease-free survival and disease-specific survival. CONCLUSIONS Radiation therapy alone appears to be an adequate and viable treatment for patients with early-stage nasopharyngeal carcinomas, whereas treatment with chemotherapy in combination with radiation therapy appears to improve outcome for patients with advanced-stage nasopharyngeal carcinomas.
Journal of Laryngology and Otology | 1997
Sevgi Y. Kurtulmaz; Haldun Şükrü Erkal; Meltem Serin; Atilla Halil Elhan; Ahmet Çakmak
Medical reports of 1293 patients with squamous cell carcinoma (SCC) of the head and neck were retrospectively evaluated. The patients were classified according to their age, sex, primary tumour localization and tumoral stage. There were 1181 males (91.3 per cent) and 112 females (8.7 per cent), with a male to female ratio of 10.5:1. The peak incidences for all primary tumour localizations were observed in the fifth decade. Most common primary tumour localizations were the larynx (71.1 per cent), the nasopharynx (10.1 per cent) and the oral cavity (8.8 per cent). Of all patients in whom staging was complete, 43.1 per cent presented at early and 56.9 per cent at advanced stages. The proportion of patients presenting with metastatic neck nodes was 34.4 per cent and the incidence of metastatic neck nodes increased with increasing T stage. The supraglottic region was the most common primary site among all laryngeal SCC, with a supraglottic to glottic SCC ratio of 1.5:1. Glottic SCC presented at earlier stages compared to supraglottic SCC. The incidence of nodal metastases increased with increasing T stage for SCC of the larynx, the oral cavity and the oropharynx.
Radiotherapy and Oncology | 1999
Meltem Serin; HaldunŞükrü Erkal; Ahmet Çakmak
Fifty-three patients with carcinomas of the head and neck with N2 or N3 metastatic cervical lymph nodes were treated with radiation therapy (median, 70 Gy), cisplatin (median, 6 weekly courses) and hyperthermia (median, 6 twice weekly sessions). Local complete response was achieved in 82% and nodal complete response in 85% of patients. Overall survival was 51% and disease-free survival was 54% at 2 years. Toxicity was acceptable. Radiation therapy, cisplatin and hyperthermia in combination prove to be effective and safe in management of these patients.
Tumori | 1997
Haldun Şükrü Erkal; Meltem Serin; Serpil Dizbay Sak; Ahmet Çakmak
Aims and Background The orbit is an uncommon primary site for non-Hodgkins lymphomas (NHL), and it accounts for less than 1% of all sites of primary presentations. We report the experience of the Department of Radiation Oncology at Ankara University Faculty of Medicine with radiation therapy in treatment of patients with stage I primary orbital NHL. Methods From February 1978 through August 1993, 14 patients with stage I primary orbital NHL were treated with radiation therapy. According to the Working Formulation classification, 8 patients had low-grade and 6 had intermediate-grade lymphomas. The most commonly used radiation therapy technique was a single anterior field with a Cobalt-60 unit, delivering 40 Gy in 2 Gy daily fractions. Two patients with intermediate-grade lymphomas received the CHOP regimen following radiation therapy. Results Follow-up ranged from 0.8 to 18.3 years (median, 10.3 years). Local control was achieved in all patients. Two patients with low-grade lymphomas relapsed locally and were successfully salvaged with radiation therapy. Three patients with intermediate-grade lymphomas failed systemically. Salvage therapy consisted of combination chemotherapy for 2 of them but was unsuccessful. Overall survival probabilities at 2, 5 and 10 years were 78.6%, 61.1% and 52.4%, respectively, for the entire group of 14 patients. Overall, cause-specific and disease-free survival probabilities were higher for patients with low-grade lymphomas than for those with intermediate-grade lymphomas (P = 0.03, P = 0.03 and P = 0.06, respectively). Cataracts were observed in 9 and lacrimal disorders in 4 patients. Conclusions The study suggests that among stage I primary orbital NHL, low-grade lymphomas could be treated with radiation therapy alone, whereas combination chemotherapy could accompany radiation therapy for intermediate-grade lymphomas.
Tumori | 2003
Durmus Etiz; Melahat Garipagaoglu; Emine Elmas Etiz; Faruk Köse; Fulya Kayikcioglu; Ali Haberal; Leyla Citak; Ahmet Çakmak
Aims and background The objective of this study was to evaluate the results of surgery combined with postoperative radiotherapy (RT) in patients with uterine sarcoma in order to describe the patterns of relapse and to define prognostic factors. Methods We report on 29 patients with uterine sarcoma (US) treated from 1980 to 1995; 18 patients with primary tumors were treated with surgery and adjuvant irradiation, while 11 patients with local recurrences (LR) after previous surgical resection received only radiotherapy. We evaluated the influence of stage, histology, grade, menopausal status, total radiation dose and brachytherapy on survival. Histological diagnosis was leiomyosarcoma in 13 patients (44.8%), endometrial stromal sarcoma in 10 patients (34.5%), and mixed mesodermal tumors in six patients (20.7%). Fifteen patients presented with stage I-II disease, three with stage III, and 11 with local recurrences. External pelvic RT was administered to all patients, in five patients combined with brachytherapy. The mean total dose was 54 Gy (SE 1.78). Univariate and multivariate analyses were carried out. Results Overall survival (OS) for the stage I-III group was 61.1% at two years and 33.3% at five years (median 29 months, SE 13.79). Disease-free survival (DFS) was 55.6% at two years and 33.3% at five years. Median DFS was 26 months (SE 14.85). In LR cases, median OS was only 10 months (SE 4.5). Multivariate analysis demonstrated that stage was the only prognostic factor after RT for US. Conclusions These data suggest that postoperative and/or salvage RT has a questionable impact on disease-free and overall survival because of the lack of homogeneity of stages in the series reported in the literature; it has, however, acceptable late side effects. Prospective multicenter trials including a statistically evaluable number of patients are necessary to further clarify the role of RT treatment programs for US.
International Journal of Hyperthermia | 1999
Meltem Serin; H.S. Erkal; Ahmet Çakmak
Twenty-one patients with recurrent carcinomas of the head and neck with metastatic cervical lymph nodes were treated with radiation therapy, cisplatin and hyperthermia in combination, in an attempt to investigate any potential contribution in terms of safety, response, duration of palliation and quality of life. Patients not initially treated with radiation therapy were treated with a median dose of 70 Gy and patients initially treated with radiation therapy with a median dose of 30Gy. The median number of weekly cisplatin courses was five and the median number of twice weekly local external ultrasound hyperthermia sessions was five. Average T90, Average T50 and Average T10 were 39.9 +/- 1.2 degrees C, 42.4 +/- 1.3 degrees C and 44.5 +/- 0.8 degrees C, respectively, and Average CEM 43 degrees C T90, Average CEM 43 degrees C T50 and Average CEM 43 degrees C T10 were 7.8+/-9.6min, 22.6 +/- 18.8min and 39.3 +/- 25.1min, respectively. Mean follow-up was 1 year. Nodal complete response was achieved in eight patients and palliation of presenting symptoms in 19. Overall survival was 39% at 1 year. Grade 3 acute skin toxicity was observed in one patient and Grade 3 acute haematological toxicity in one. Radiation therapy, cisplatin and hyperthermia in combination appear to be safe and might improve response, prolong duration of palliation and reinstate quality of life in patients with recurrent carcinomas of the head and neck with metastatic cervical lymph nodes.
Tumori | 2002
Durmus Etiz; Orhan B; Canan Demirüstü; Kazim Özdamar; Ahmet Çakmak
Background A number of oral toxicity scoring systems have been described, but their direct comparison has rarely been undertaken and little data exists. An impediment to mucositis research has been the lack of an accepted, validated scoring system. The objective of this study was to design a test and validation of scoring systems. Materials and methods Forty-three patients with head and neck malignancies who had been irradiated were evaluated. Five different mucositis scoring systems (World Health Organization, Radiation Therapy Oncology Group, “Hickey”, “Van der Schueren” and “Makkonen”) were compared with each other. Results Daily mucositis scores demonstrated a high correlation among scoring systems (P <0.05 and coefficient of correlation κ and r = 0.5 - 0.95). Objective mucositis scores demonstrated a strong correlation with symptoms. Conclusions All scoring systems were equally valid. The exact grading of mucositis is achieved by combining clinical information about pain and nutritional status with oral mucosal reactions.
Tumori | 2000
Zafer Kocak; Mustafa Adli; Ozlem Erdir; Selim Erekul; Ahmet Çakmak
We report on a de novo desmoid tumor of the posterior mediastinum with transdiaphragmatic extension in a 40-year-old man. The tumor was inoperable because of its location and the invasion of adjacent structures. Although extremely rare, desmoid tumors of the posterior mediastinum should be considered in the differential diagnosis of posterior mediastinal masses.