Guntulu Ak
Eskişehir Osmangazi University
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Featured researches published by Guntulu Ak.
Chest | 2010
Muzaffer Metintas; Guntulu Ak; Emine Dundar; Huseyin Yildirim; Ragip Ozkan; Emel Kurt; Sinan Erginel; Fusun Alatas; Selma Metintas
BACKGROUND In cases of pleural effusion, tissue samples can be obtained through Abrams needle pleural biopsy (ANPB), thoracoscopy, or cutting-needle pleural biopsy under the guidance of CT scan (CT-CNPB) for histopathologic analysis. This study aimed to compare the diagnostic efficiency and reliability of ANPB under CT scan guidance (CT-ANPB) with that of medical thoracoscopy in patients with pleural effusion. METHODS Between January 2006 and January 2008, 124 patients with exudative pleural effusion that could not be diagnosed by cytologic analysis were included in the study. All patients were randomized after the CT scan was performed. Patients either underwent CT-ANPB or thoracoscopy. The two groups were compared in terms of diagnostic sensitivity and complications associated with the methods used. RESULTS Of the 124 patients, malignant mesothelioma was diagnosed in 33, metastatic pleural disease in 47, benign pleural disease in 42, and two were of indeterminate origin. In the CT-ANPB group, the diagnostic sensitivity was 87.5%, as compared with 94.1% in the thoracoscopy group; the difference was not statistically significant (P = .252). No difference was identified between the sensitivities of the two methods based on the cause, the CT scan findings, and the degree of pleural thickening. Complication rates were low and acceptable. CONCLUSION We recommend the use of CT-ANPB as the primary method of diagnosis in patients with pleural thickening or lesions observed by CT scan. In patients with only pleural fluid appearance on CT scan and in those who may have benign pleural pathologies other than TB, the primary method of diagnosis should be medical thoracoscopy. TRIAL REGISTRATION clinicaltrials.gov; Identifier: NCT00720954.
Journal of Thoracic Oncology | 2009
Huseyin Yildirim; Muzaffer Metintas; Emre Entok; Guntulu Ak; İlknur Ak; Emine Dundar; Sinan Erginel
Background: Several studies have already addressed the potential role of an increased fluorine 18 fluorodeoxyglucose (18F FDG) uptake in identification of pleural malignancy. In this pilot study, we investigate the role of 18F-FDG positron emission tomography/computed tomography (PET/CT) for differentiating asbestos-related benign pleural disease from malignant mesothelioma. Materials and Methods: The study population comprised 31 consecutive patients (17 malignant mesotheliomas, nine benign asbestos pleurisies, and five diffuse pleural fibrosis) with a mean age of 61 years between January 2006 and December 2008. Thoracoscopy or image-guided pleural needle biopsy were systematically performed to reveal pathologic diagnosis and/or clinical follow-up for at least 3 years for presence or absence of malignant pleural effusion. ROCs analyses for standardized uptake value (SUV) adjusted to body weight were calculated between benign and malignant pleural diseases. Results: 18F-FDG PET/CT imaging correctly detected the presence of malignancies in 15 of 17 patients with malignant mesothelioma for sensitivity, specificity, and overall accuracy of 88.2%, 92.9%, and 90.3%, respectively. 18F-FDG PET/CT imaging correctly identified 13 of 14 cases of benign pleural disease. The mean SUV values were 6.5 ± 3.4 for malignant mesothelioma cases and 0.8 ± 0.6 for benign pleural diseases (p < 0.001). When we compared the two groups of pleural disease, a cut-off value of 2.2 for SUV gave the best accuracy with 94.1%, 100%, 100%, and 93.3% for sensitivity, specificity, positive predictive value, and negative predictive value, respectively. Conclusion: Preliminary results of this trial provide evidence that 18F-FDG PET/CT imaging is a highly accurate and reliable noninvasive test to decide for further investigation of differentiating malignant mesothelioma from benign pleural disease.
Journal of Thoracic Oncology | 2009
Guntulu Ak; Selma Metintas; Muzaffer Metintas; Huseyin Yildirim; Sinan Erginel; Emel Kurt; Fusun Alatas; Omer Cadirci
Objectives: In this study, we aimed to investigate the factors affecting the survival of patients with malignant pleural mesothelioma (MPM) according to their treatment schedules, including those treated with best supportive care, chemotherapy, and multimodality therapy. Methods: We evaluated 235 patients with MPM. The patients were classified into three groups according to their treatment schedules: the best supportive care group, the chemotherapy group, and the multimodality therapy group. Prognostic factors were determined for all patients and for the three groups by univariate and multivariate analyses. However, the effectiveness of treatment schedules as a prognostic factor was not evaluated in this study. Results: After adjusting for therapy in a Cox model, a Karnofsky Performance Status (KPS) ≤70, a right side tumor, serum lactate dehydrogenase >500 IU−1, a nonepithelial subtype, and stage 3 to 4 disease were determined by multivariate analyses to be unfavorable prognostic factors for all the patients. A KPS ≤70, serum lactate dehydrogenase >500 IU−1, a nonepithelial subtype, and stage 3 to 4 disease were associated with a poor prognosis for the best supportive care group. The single unfavorable prognostic factor for the chemotherapy group was a KPS ≤70. A right side tumor and a nonepithelial subtype were associated with a poor prognosis for the multimodality therapy group. Conclusions: The patients with an epithelial subtype, a good KPS, and an early-stage tumor had a good prognosis, even if they did not receive any treatment. The only prognostic factor for the chemotherapy group was KPS. The histologic subtype and stage of the tumor were not related to the prognosis in this group. A mixed subtype and a right side tumor were unfavorable prognostic factors for the multimodality therapy group. These findings may be useful in counseling patients and in planning further studies.
Lung Cancer | 2008
Huseyin Yildirim; Muzaffer Metintas; Guntulu Ak; Selma Metintas; Sinan Erginel
OBJECTIVE Chemical pleurodesis is an accepted palliative therapy for patients with recurrent, symptomatic, malignant pleural effusions (MPE). The purpose of the study was to determine the factors that have an effect on successful pleurodesis for MPE. PATIENTS AND INTERVENTIONS Eighty-four consecutive patients with biopsy-proven malignant pleural disease and recurrent, symptomatic MPE were eligible to participate in this study. Five grams of talc mixed in 150ml of normal saline were administered via tube thoracostomy or small-bore catheters after complete drainage of the pleural effusion. RESULTS Seven patients did not return for their 30-day follow-up visit and were excluded from further analysis. Successful pleurodesis was achieved in 63 of 77 eligible patients (81.8%) with MPE. In the univariate analysis, female gender, Karnofsky performance status, pleural fluid pH, cholesterol, and adenosine deaminase level showed a significant association with the probability of success. Multivariate logistic regression analysis showed that pleural fluid pH and ADA levels were independent predictors of talc pleurodesis outcome. CONCLUSION Our results show that pleurodesis using talc as the sclerosing agent is a simple and acceptable procedure with high efficacy for controlling MPE, especially when used in appropriate patients.
Lung Cancer | 2008
Muzaffer Metintas; Guntulu Ak; Sebnem Parspour; Huseyin Yildirim; Sinan Erginel; Fusun Alatas; Hasan Fevzi Batirel; Cumhur Sivrikoz; Selma Metintas; Emine Dundar
In malignant pleural mesothelioma (MPM) patients, local dissemination (LD) of the tumor is frequently observed at the sites of intervention where diagnosis/treatment are performed. We evaluate the factors affecting LD frequency and discuss the use of PR in MPM patients. Histopathologically diagnosed 212 MPM patients who had not received PR were evaluated in terms of development of LD. Of the 212 patients, 29 received supportive therapy, 157 received chemotherapy and 26 received multi-modal therapy. The LD frequency was 13.2% for all patients. The median survival rate was 9 or 10 months in patients with or without LD, respectively. A higher LD frequency was observed in patients receiving thoracotomy. The LD appearance time in supportive care is short. The LD frequency in patients treated with chemotherapy that revealed progressive disease was higher than the patients who revealed stable disease or objective response. LD developed in 2 months in patients with sarcomatous and mixed cell type, and the survival rate was low. LD was not associated with the stage of the disease. The most suitable candidate groups for PR are patients receiving supportive therapy, thoracotomy without multi-modal therapy or patients with sarcomatous and mixed cell type tumors.
European Journal of Radiology | 2010
Guntulu Ak; Muzaffer Metintas; Selma Metintas; Huseyin Yildirim; Ragip Ozkan; Hilmi Ozden
OBJECTIVES Measurement of tumor response to chemotherapy in malignant pleural mesothelioma (MPM) is problematic because of non-spherical tumor growth patterns and difficulty in choosing target lesion. In this study, we aimed to determine the effectiveness of tumor volume measurement for evaluating chemotherapy response. METHODS Fifty-seven MPM patients were included. Chemotherapy responses were evaluated by computed tomography (CT) using volumetric method, World Health Organization (WHO), and modified Response Evaluation Criteria in Solid Tumor (RECIST). The tumor volume was measured using the Cavalieri principle of stereological approaches. RESULTS According to the volumetric method, median survival was 10.0 months for progressive disease (PD), 14.0 months for stable disease (SD) and 16.0 months for objective response (OR). According to the WHO method, median survival was 11.3, 14.0, and 13.0 months, respectively. For modified RECIST, median survival was 10.0, 14.0, and 14.0 months, respectively. The correspondence between the WHO and modified RECIST methods was substantial (K=0.66), as was that between the volumetric and WHO methods (K=0.64); however the correspondence between the volumetric and modified RECIST methods was only moderate (K=0.52). CONCLUSIONS The most suitable chemotherapy response measurement technique is the volumetric method because of non-spherical tumor growth patterns in MPM. However, larger studies should be performed to better establish the suitability of this method. We recommend our method for determining the chemotherapy response in mesothelioma cases. However, modified RECIST criteria can also be applied due to favourable prediction of survival, ease of application, and moderate correspondence with the volumetric method.
The Journal of Thoracic and Cardiovascular Surgery | 2016
Hasan Fevzi Batirel; Muzaffer Metintas; Hale B. Caglar; Guntulu Ak; Perran Fulden Yumuk; Bedrettin Yildizeli; Mustafa Yüksel
OBJECTIVE We changed our surgical approach to malignant pleural mesothelioma (MPM) in August 2011 and adopted pleurectomy and decortication (PD) instead of extrapleural pneumonectomy (EPP). In this study, we analyzed our perioperative and survival results during the 2 periods. METHODS All patients who underwent surgical intervention for MPM during 2003-2014 were included. Data were retrospectively analyzed from a prospective database. Before August 2011, patients underwent evaluation for EPP and adjuvant chemoradiation (group 1). After August 2011, patients were evaluated for PD and adjuvant chemotherapy and/or radiation (group 2). Demographic characteristics, surgical technique, histology, side, completeness of resection, and types of treatments were recorded. Statistics was performed using Student t test, χ(2) tests, uni- and multivariate regression, and Kaplan-Meier survival analysis. RESULTS The same surgical team operated on 130 patients. Median age was 55.7 years (range, 26-80 years) and 76 were men. EPP and extended PD was performed in 72 patients. Ninety-day mortality was 10%. Median survival was 17.8 months with a 5-year survival rate of 14%. Uni- and multivariate analyses showed that epithelioid histology, stage N0, and trimodality treatment were associated with better survival (P = .039, P = .012, and P < .001, respectively). Demographic variables and overall survival (15.6 vs 19.6 months, respectively) were similar between the groups, whereas nonepithelioid histology, use of preoperative chemotherapy, and incomplete resections were more frequent in group 2 (P < .001, P < .001, and P = .006, respectively). Follow-up was shorter in group 2 (22.5 ± 20.6 vs 16.4 ± 10.9 months; P < .001). CONCLUSIONS Adoption of PD as the main surgical approach is not associated with survival disadvantage in the surgical treatment of MPM.
Lung | 2007
Guntulu Ak; Muzaffer Metintas; Selma Metintas; Huseyin Yildirim; Sinan Erginel; Fusun Alatas
The aim of this study was to compare the epidemiologic, clinical, and laboratory characteristics and survival rates of younger and older patients with lung cancer. We studied 1340 patients who were histopathologically diagnosed as having lung cancer from 1990 to 2005. Based on prior reports, we defined “younger” as individuals less than 50 years old. The patients were classified into two groups: <50 years (the younger group) and ≥50 years (the older group). Of the 1340 patients, 179 (13.4%) were in the younger group and 1161 were in the older group. In the younger group, exposure to occupational risk factors was a risk factor for lung cancer, while in the older group, smoking was a risk factor. At the time of diagnosis, chest pain was more common in the younger group, while in the older group, cough, dyspnea, and hilar enlargement on chest X-ray were more frequent. The incidence of adenocarcinoma and small-cell carcinoma was greater in the younger group, while squamous cell carcinoma was more common in the older group. Metastasis rates were significantly different between the two age groups: 52.0% of the younger group presented with stage IV disease compared with 43.5% of the older group. Although fewer younger than older patients were not able to receive or rejected anticancer therapy, the overall survival was similar in both groups. These data indicate that lung cancer had different etiopathogenetic characteristics in younger patients, which may have clinical implications. By planning preventive measures based on these characteristics, more efficient use of resources can be achieved.
BioMed Research International | 2015
Guntulu Ak; Sandra C. Tomaszek; Farhad Kosari; Muzaffer Metintas; James R. Jett; Selma Metintas; Huseyin Yildirim; Emine Dundar; Jie Dong; Marie Christine Aubry; Dennis A. Wigle; Charles F. Thomas
Introduction. We investigated the expression of microRNAs and mRNAs in pleural tissues from patients with either malignant pleural mesothelioma or benign asbestos-related pleural effusion. Methods. Fresh frozen tissues from a total of 18 malignant pleural mesothelioma and 6 benign asbestos-related pleural effusion patients were studied. Expression profiling of mRNA and microRNA was performed using standard protocols. Results. We discovered significant upregulation of multiple microRNAs in malignant pleural mesothelioma compared to benign asbestos-related pleural effusion. Hsa-miR-484, hsa-miR-320, hsa-let-7a, and hsa-miR-125a-5p were able to discriminate malignant from benign disease. Dynamically regulated mRNAs were also identified. MET was the most highly overexpressed gene in malignant pleural mesothelioma compared to benign asbestos-related pleural effusion. Integrated analyses examining microRNA-mRNA interactions suggested multiple altered targets within the Notch signaling pathway. Conclusions. Specific microRNAs and mRNAs may have diagnostic utility in differentiating patients with malignant pleural mesothelioma from benign asbestos-related pleural effusion. These studies may be particularly helpful in patients who reside in a region with a high incidence of mesothelioma.
Respiratory Medicine | 2012
Muzaffer Metintas; Guntulu Ak; Omer Cadirci; Huseyin Yildirim; Emine Dundar; Selma Metintas
BACKGROUND In patients with post- medical thoracoscopy histopathological diagnoses of fibrinous pleuritis, confusion can occur concerning subsequent procedures. This issue is particularly important in regions where mesothelioma is prevalent. We aimed to identify false negatives among patients where mesothelioma was common due to asbestos exposure whose histopathological diagnosis following thoracoscopy was fibrinous pleuritis. We also determined risk factors associated with patients that required additional advanced invasive procedures for diagnosis. METHODS Overall, 287 patients who underwent thoracoscopy were included in the study. Patients diagnosed with fibrinous pleuritis as a result of thoracoscopy were followed for 2 years regarding this condition. More invasive procedures were performed on patients who showed no recuperation or developed pleural disease again during the follow-up period. RESULTS Fibrinous pleuritis was observed in 101 (35.2%) patients. Follow-up of these patients revealed that the false negative rate was 18% for malignant pleural diseases. The thoracoscopists opinion regarding the pleural space, computed tomography scan findings indicating malignancy, pain and female gender were determined to be risk factors for malignant pleural diseases. CONCLUSIONS In regions where mesothelioma is prevalent and one of the above-stated risk factors is present, patients whose post-thoracoscopy histopathological diagnosis is fibrinous pleuritis should be treated with a more advanced invasive diagnosis procedure.