Browsing by Author "Kaya, Eser"

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Can Laws Be a Potential PET Image Texture Analysis Approach for Evaluation of Tumor Heterogeneity and Histopathological Characteristics in NSCLC?
(SPRINGER, 2018-01-01) Karacavus, Seyhan; Yilmaz, Bulent; Tasdemir, Arzu; Kayaalti, Omer; Kaya, Eser; Icer, Semra; Ayyildiz, Oguzhan
We investigated the association between the textural features obtained from F-18-FDG images, metabolic parameters (SUVmax(,) SUVmean, MTV, TLG), and tumor histopathological characteristics (stage and Ki-67 proliferation index) in non-small cell lung cancer (NSCLC). The FDG-PET images of 67 patients with NSCLC were evaluated. MATLAB technical computing language was employed in the extraction of 137 features by using first order statistics (FOS), gray-level co-occurrence matrix (GLCM), gray-level run length matrix (GLRLM), and Laws' texture filters. Textural features and metabolic parameters were statistically analyzed in terms of good discrimination power between tumor stages, and selected features/parameters were used in the automatic classification by k-nearest neighbors (k-NN) and support vector machines (SVM). We showed that one textural feature (gray-level nonuniformity, GLN) obtained using GLRLM approach and nine textural features using Laws' approach were successful in discriminating all tumor stages, unlike metabolic parameters. There were significant correlations between Ki-67 index and some of the textural features computed using Laws' method (r = 0.6, p = 0.013). In terms of automatic classification of tumor stage, the accuracy was approximately 84\% with k-NN classifier (k = 3) and SVM, using selected five features. Texture analysis of FDG-PET images has a potential to be an objective tool to assess tumor histopathological characteristics. The textural features obtained using Laws' approach could be useful in the discrimination of tumor stage.
Colonic Malignant Melanoma: F-18-FDG PET/CT Findings
(GALENOS YAYINCILIK, 2018-01-01) Kaya, Eser; Aksoy, Tamer; Guner, Ahmet Levent; Temiz, Hakan; Vardareli, Erkan
Primary malignant melanoma occurs most often in the skin and much less frequently in the choroid layer of the eyes, in the leptomeninges, oral cavity, nasal mucosa, pharynx, esophagus, bronchus, under the nail and vaginal or anorectal mucosa. Primary melanoma of the gastrointestinal tract has been confirmed for lesions occurring in the esophagus, stomach, small bowel, and anorectum through several published reports, as these are the areas where melanocytes normally exist. The occurrence of primary malignant melanoma in the colon is relatively rare, because melanocytes are embryologically absent in the large bowel. Herein we report a patient whose colonic malignant melanoma was diagnosed and disseminated metastatic lesions were revealed with F-18-FDG PET/CT scan. There were multiple nodular lesions showing increased F-18-FDG uptake in both lungs. There was a soft tissue lesion with slightly increased F-18-FDG uptake, which extended to the intraluminal region of the thoracic esophagus. Increased metabolic activity was detected in the asymmetric stomach wall thickening site and in a soft tissue lesion located on the gall bladder wall that was filling the lumen. Multiple hypodense/hyper-metabolic lesions were identified in the liver. Multiple hyper-metabolic polypoid soft tissue lesions were visualized in almost the entire colonic segments. Multiple hyper-metabolic peritoneal implants were noted in all abdominal quadrants. Increased F-18-FDG uptake was detected at the right surrenal gland soft tissue lesion. There was a hyper-metabolic soft tissue lesion on the posterior wall of the rectum. Hyper-metabolic lytic lesions were seen at the thoracal and lumbar vertebrae, left scapula, left iliac bone, sacrum and left femur. There was no evidence of F-18-FDG avid skin lesions in both attenuation corrected and non-corrected images.
Does Sunlight Exposure Improve Survival in Patients with Non-small Cell Lung Cancer?
(ASIAN PACIFIC ORGANIZATION CANCER PREVENTION, 2013-01-01) Mutlu, Hasan; Buyukcelik, Abdullah; Aksahin, Arzu; Kibar, Mustafa; Cihan, Yasemin Benderli; Kaya, Eser; Seyrek, Ertugrul; Yavuz, Sinan; Erden, Abdulsamet; Calikusu, Zuleyha; Aslan, Tuncay; Akca, Zeki
Background: Some epidemiological studies reported that sunlight exposure and highvitamin D levels may decrease the morbidity and mortality related to cancer. We aimed to evaluate whether sunlight exposure has an impact on survival in patients with non small cell lung cancer. Materials and Methods: A total of 546 patients with NSCLC from two different regions (Kayseri and Adana) differing according to sunlight exposure were analysed retrospectively. Results: The median overall survival (OS) rates were 11. 6 (CI: 9.50-13.6) and 15.6 months (CI: 12.4-18.8) for Kayseri and Adana, respectively, in all patients (p=0.880). Conclusions: There were no differences between groups in terms of OS. While there is strong evidence regarding inverse relationship between cancer incidence and sunlight exposure, it is still controversial whether sunlight exposure is a good prognostic factor for survival in patients with lung cancer.
Lung cancer subtype differentiation from positron emission tomography images
(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2020-01-01) Ayyildiz, Oguzhan; Aydin, Zafer; Yilmaz, Bulent; Karacavus, Seyhan; Senkaya, Kubra; Icer, Semra; Tasdemir, Arzu; Kaya, Eser
Lung cancer is one of the deadly cancer types, and almost 85\% of lung cancers are nonsmall cell lung cancer (NSCLC). In the present study we investigated classification and feature selection methods for the differentiation of two subtypes of NSCLC, namely adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). The major advances in understanding the effects of therapy agents suggest that future targeted therapies will be increasingly subtype specific. We obtained positron emission tomography (PET) images of 93 patients with NSCLC, 39 of which had ADC while the rest had SqCC. Random walk segmentation was applied to delineate three-dimensional tumor volume, and 39 texture features were extracted to grade the tumor subtypes. We examined 11 classifiers with two different feature selection methods and the effect of normalization on accuracy. The classifiers we used were the k-nearest-neighbor, logistic regression, support vector machine, Bayesian network, decision tree, radial basis function network, random forest, AdaBoostM1, and three stacking methods. To evaluate the prediction accuracy we performed a leave-one-out cross-validation experiment on the dataset. We also considered optimizing certain hyperparameters of these models by performing 10-fold cross-validation separately on each training set. We found that the stacking ensemble classifier, which combines a decision tree, AdaBoostM1, and logistic regression methods by a metalearner, was the most accurate method for detecting subtypes of NSCLC, and normalization of feature sets improved the accuracy of the classification method.
Staging with PET-CT in Patients with Locally Advanced Non Small Cell Lung Cancer is Superior to Conventional Staging Methods in Terms of Survival
(ASIAN PACIFIC ORGANIZATION CANCER PREVENTION, 2013-01-01) Mutlu, Hasan; Buyukcelik, Abdullah; Erden, Abdulsamet; Aslan, Tuncay; Akca, Zeki; Kaya, Eser; Kibar, Mustafa; Seyrek, Ertugrul; Yavuz, Sinan; Calikusu, Zuleyha
Background: Of patients with non small cell lung cancer (NSCLC), around one third are locally advanced at the time of diagnosis. Because only a proprotion of stage III patients can be cured by surgery, in order to improve the outcomes, sequential or concurrent chemoradiation, or concurrent chemoradiation with induction or consolidation is offered to the patients with locally advanced NSCLC. Today, PET combined with computerized tomography (PET-CT) is accepted as the most sensitive technique for detecting mediastinal lymph node and extracranial metastases from NSCLC. We aimed to compare PET-CT and conventional staging procedures for decisions regarding curative treatment of locally advanced NSCLC. Materials and Methods: A total of 168 consecutive patients were included from Acibadem Kayseri Hospital, Acibadem Adana Hospital and Kayseri Research and Training Hospital in this study. Results: While the median PFS was 13.0 +/- 1.9 months in the PET-CT group, it was only 6.0 +/- 0.9 in the others (p<0.001). The median OS values were 20.5 +/- 15.6 and 11.5 +/- 1.5 months, respectively (p<0.001). Discussion: As a result, we found that staging with PET CT has better results in terms of survival staging. This superiority leads to survival advantage in patients with locally advanced NSCLC.
Sunlight may increase the FDG uptake value in primary tumors of patients with non-small cell lung cancer
(SPANDIDOS PUBL LTD, 2013-01-01) Mutlu, Hasan; Buyukcelik, Abdullah; Kaya, Eser; Kibar, Mustafa; Seyrek, Ertugrul; Yavuz, Sinan; Calikusu, Zuleyha
Currently, positron emission tomography with computerized tomography (PET-CT) is the most sensitive technique for detecting extracranial metastases in non-small cell lung cancer (NSCLC). It has been reported that there is a correlation between the maximal standardized uptake value (SUVmax) of primary tumors and prognosis in patients with NSCLC. The effect of sunlight exposure on PET-CT SUVmax value is not known. Therefore, we aimed to evaluate the effect of sunlight exposure on PET-CT SUVmax a value in patients with NSCLC. A total of 290 patients with NSCLC from two different regions of Turkey (Kayseri, n=168 and Adana, n=122) that have different climate and sunlight exposure intensity, were included in the study. Age, gender, histology of cancer, cancer stage, smoking status, comorbidity and SUVmax of the primary tumor area at the time of staging were evaluated as prognostic factors. In the multivariate analysis, we detected that the region was the only independent factor affecting SUVmax (P=0.019). We identified that warmer climate and more sunlight exposure significantly increases the SUVmax value of the primary tumor area in patients with NSCLC. Further studies are warranted to clarify the issue.