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Featured researches published by Recep Bekis.


Journal of Otolaryngology | 2005

Assessment of cervical lymph node metastasis with different imaging methods in patients with head and neck squamous cell carcinoma.

Ertap Akoglu; Murat Dutipek; Recep Bekis; Berna Degirmenci; Emel Ada; Ataman Güneri

OBJECTIVE To determine the predictive value of different imaging methods,-computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US), and single-photon emission tomography (SPECT),-for cervical node metastasis. DESIGN Prospective clinical trial. SETTING An academic otolaryngology department. METHODS Twenty-three consecutive patients with head and neck malignancy were prospectively evaluated for the presence of cervical lymphadenopathy. All patients underwent clinical, CT, MRI, US, and SPECT examinations. Neck dissection was performed for 31 neck sides, and the results of the preoperative evaluation were confirmed by the surgical and histopathologic findings. MAIN OUTCOME MEASURES The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for each method and a comparison of the methods was done. RESULTS The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT, MRI, US, and SPECT were 77.7%, 85.7%, 91.3%, 66.6%, and 80.4%; 59.2%, 92.8%, 94.1%, 54.1%, and 70.7%; 81.4%, 64.2%, 81.4%, 64.2%, and 75.6%; 55.5%, 92.8%, 93.7%, 52.0%, and 68.2%, respectively. Both CT and US were found to be superior to clinical examination. There was no statistically significant difference between US and CT. US was found to be superior to MRI and SPECT in detecting cervical node metastasis. CT was also superior to SPECT. CONCLUSION Our data show that, despite high specificity rates, especially with SPECT, none of the currently available imaging methods are reliable in evaluating the occult regional metastasis because the negative predictive values of all of these methods are rather low.


Annals of Nuclear Medicine | 2002

Technetium-99m HMPAO brain SPECT in children with attention deficit hyperactivity disorder

Gamze Çapa Kaya; Aynur Akay Pekcanlar; Recep Bekis; Emel Ada; Süha Miral; Neslihan Emiroĝlu; Hatice Durak

Attention deficit hyperactivity disorder (ADHD) is a developmental, neurobehavioral syndrome with an onset in childhood. The aim of this study was to investigate the existence of regional perfusion changes in ADHD by means of Tc-99m HMPAO brain SPECT. Thirteen children with a diagnosis of ADHD and 7 healthy, age-matched controls were included in this study. Hypoperfusion was observed on the right temporal cortex in 9, and on the left temporal cortex in 3 children. The distribution of the lesions showed right lateral temporal cortex involvement in 3, right medial temporal cortex in 9 and left medial temporal cortex in 8 children. The distribution of the lesions showed right lateral temporal cortex involvement in 3, right medial temporal cortex in 9 and left medial temporal cortex in 8 children. Asymmetric perfusion was seen on the caudate nucleus in 4, on the thalamus in 3 and on the frontal cortex in 6 children. There was a significant difference between children with ADHD and controls in right medial temporal cortex: cerebellum and righ lateral temporal cortex: cerebellum ratios. Hypoperfusion in the right medial temporal cortex was significantly and inversely correlated with Du Paul teachers’ questionnaire rating scale (r=−0.71, p=0.0006). It has been postulated that difficulty in self regulating response to stimuli in ADHD is mediated by underfunctioning of the orbital frontal cortex and subsequent connection to the limbic system. Decreased temporal cortex perfusion may dysfunction of the limbic system or the orbito-frontal-limbic axis.


Nuclear Medicine and Biology | 2001

New radiolabeled CCK-8 analogues [Tc-99m-GH-CCK-8 and Tc-99m-DTPA-CCK-8]: preparation and biodistribution studies in rats and rabbits

Türkan Ertay; Perihan Unak; Recep Bekis; F. Yurt; F. Z. Biber; Hatice Durak

The aim of this study is to label CCK-8 with Tc-99m and to investigate its radiopharmaceutical potential. CCK-8 was labeled with Tc-99m using GH and DTPA as bifunctional chelating agents. Labeling efficiency was higher than 99%. Complex was stable more than 5 hours at room temperature. 37 MBq Tc-99m-GH-CCK-8 or Tc-99m-DTPA-CCK-8 was administered intravenously to rabbits for biodistribution experiments. Dynamic and static images were obtained from anterior projection using a Camstar XC/T gamma camera. For quantitative evaluation, regions of interest were drawn on organs and time-activity curves were generated. The highest accumulation occurred in brain within 10 and 30 minutes after injection. Renal and hepatobiliary excretion were observed. Brain distribution studies in rats showed the highest activity was in hypothalamus. Results demonstrated that Tc-99m-GH-CCK-8 and Tc-99m-DTPA-CCK-8 analogs may be a useful new class of receptor-binding peptides for diagnosis and therapy of brain diseases related with CCK-B receptor-expressing tumors.


Molecular Imaging and Radionuclide Therapy | 2014

The Role of 18F-FDG PET/CT in the Evaluation of Gastric Cancer Recurrence

Hakan Cayvarlı; Recep Bekis; Tülay Akman; Deniz Altun

Objective: F-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) has been widely used for staging, re-staging and for monitoring therapy-induced changes and response to therapy in patients with various types of cancer, but its utilization for gastric cancer has been limited. This study aimed to assess the diagnostic performance of 18F-FDG PET/CT for detecting recurrence in gastric cancer patients with radiologic or clinical suspicion of recurrence and its clinical impact on making decision. Methods: We performed a retrospective review of 130 consecutive patients who underwent PET/CT scans for post-treatment surveillance of gastric cancer between January 2008 and March 2012. The mean time between the initial diagnosis of gastric cancer and PET/CT studies was 44 weeks with a median of 18 weeks. The number and site of positive FDG uptake were analyzed and correlated with the final diagnosis by calculating the diagnostic values. We evaluated the diagnostic accuracy of PET/CT for detecting the recurrence in terms of whether or not histology had been SRC/musinous adenocarcinoma. The changes in the clinical management of patients were also evaluated according to the results of PET/CT. Results: Of all 130 patients, 91 patients were confirmed to have true recurrence. The sensitivity, specificity, positive predictive value, negative predictive value and the accuracy of PET/CT for diagnosing true recurrence on a per-person basis were 91.2%, 61.5%, 84.6%, 75.0% and 82.3% respectively. Final diagnoses were confirmed histopathologically in 59 (45.4%) of 130 patients and by clinical and radiological follow-up in the remaining 71 (54.6%) patients. In the subgroup with SRC/mucinous adenocarcinoma differentiation of the primary tumor, there was no statistically significant difference in terms of diagnostic accuracy of PET/CT on a per-person basis. In addition, PET/CT results changed the patients’ management in 20 (15%) cases. Conclusions: 18F-FDG PET/CT can provide useful information in discriminating true recurrence in patients with suspected gastric cancer recurrence and may have significant impact on clinical decisions/patient management in a considerable percentage of patients.


Molecular Imaging and Radionuclide Therapy | 2013

The effect of radioiodine on the intima media thickness of the carotid artery.

Erdem Sürücü; Recep Bekis; Sengöz T; Yusuf Demir; Celik Ao; Orbay O; Birlik B; Ozhan Ozdogan; Enis Igci; Hatice Durak

Aim: The radiation can induce vessel injury. The result of this injury can be severe and life-threatening. There are a few studies demonstrating an increase in intima-media thickness (IMT) of the common carotid artery (CCA) after radiotherapy, especially in head and neck cancers. We evaluated the effect of I-131 to the IMT of the CCA in the patients who were treated for hyperthyroidism. Methods: 38 patients (25M, 13W) referred to our department for radioiodine treatment with the diagnosis of nodular goitre (25 patients) and diffuse hyperplasia (Graves disease (GD), 13 patients) were included to the prospective study. An USG was performed for all the patients before therapy, 3, 6 and 12 months after radioiodine therapy in order to measure IMT of CCA and the femoral artery (FA). The IMT was measured at the level of proximal part of bulbus anteriorly on the left and right side. The IMT of FA was measured just before the bifurcation. Results: There was a statistically significant increase in IMT of both CCA and FA bilaterally in nodular hyperthyroid patients. However, in the patients with Graves disease, there was only statistically significant increase in the left IMT of CCA at 0-3rd, 0-6th month measurements and in the right IMT of FA at 0-3rd month measurements. Conclusion: Though the limitation of the study is the interobserver and intraobserver variability, it was seen that I-131 therapy might affect the IMT of CCA in the patients with NG. I-131 effect on the IMT of CCA in patients with nodular goitre was higher than the IMT of CCA in patients with GD. I-131 effect on the IMT of CCA might be due to administered dose and adjacency. The interesting point of our study was the increased thickness of IMT in FA. We think that the increase in IMT is due to the systemic effect of radioactivity circulating in the blood vessel. I-131 effect on the IMT of FA in patients with nodular goitre was higher than the IMT of FA in the patients with GD due to I-131 uptake of thyroid gland. Because I-131 uptake was lower in patients with nodular goitre, I-131 in systemic circulation was higher. Conflict of interest:None declared.


Lung | 2006

Technetium-99m Hexamethylpropylene Amine Oxime Lung Scintigraphy Findings in Low-Dose Amiodarone Therapy

G. Capa Kaya; Türkan Ertay; Burçin Tuna; Recep Bekis; Cengiz Taşçı; Elvan Sayit; Osman Yilmaz; Aydanur Kargi; Hatice Durak

Amiodarone (AD)-induced pulmonary toxicity is one of the major complications of long-term AD therapy. Technetium-99m-labeled D,L-hexamethylpropylene amine oxime (Tc-99m HMPAO) scintigraphy has been used to assess lung injury. We designed this study to clarify lung uptake changes of Tc-99m HMPAO using low doses of AD (5 mg/kg/day) during long-term therapy in a rabbit model. Group 1 consisted of 7 rabbits fed with AD by gavage for 6 months. To investigate the effect of ketamine on Tc-99m HMPAO uptake, 5 rabbits were included in Group 2 as a control group. Tc-99m HMPAO scintigraphy was performed in both Group 1 and Group 2 at baseline and after 2, 4, 6, 8, and 12 weeks of AD intake. After 16, 20, and 24 weeks of drug intake, Tc-99m HMPAO scintigraphy was repeated only in group 1. One-min anterior images were acquired 30 min after the injection of 37 MBq of Tc-99m HMPAO. For semiquantitative evaluation, the mean count values were obtained and lung/background and liver/background ratios were calculated. Histopathologic evaluation was performed. No increase in lung and liver uptake of Tc-99m HMPAO was found 2, 4, 6, 8, and 12 weeks after drug intake. There was no significant increase in L/B and H/B ratios of Tc-99m HMPAO in Group 1 compared with Group 2. Both scintigraphic studies and histopathologic examinations showed nonspecific changes. Longitudinal studies investigating Tc-99m HMPAO lung uptake may be planned in patients carrying risk factors for AD-induced lung toxicity.


Annals of Nuclear Medicine | 2002

Comparison of brain perfusion SPECT and MRI findings in children with neuronal ceroid-lipofuscinosis and in their families

Elvan Sayit; Ilginn Yorulmaz; Recep Bekis; Gamze Çapa Kaya; F. Gul Gumuser; Eray Dirik; Hatice Durak

Purpose: Neuronal ceroid lipofuscinoses (NCL) are among the progressive encephalopathies of childhood that are inherited in an autosomal recessive manner. In this study we specifically aimed to investigate any white-matter changes in the carriers (parents) and the healthy siblings of individuals with neuronal ceroid lipofuscinosis disease and whether we may be able to predict the occurrence of any neurological symptoms in healthy children in the future thus enabling early management.Materials and Methods: Since the NCLs are genetically determined diseases, we investigated fifteen individuals in three families that had diseased children of the juvenile type, with brain perfusion SPECT and MRI. Brain perfusion SPECT was performed after administering 222–555 MBq (6–15 mCi) Tc-99m HMPAO intravenously in a dimmed and quiet room. Imaging was performed at least one hour after injection, with a three headed gamma camera equipped with high resolution collimators. A Metz filter (FWHM: 11 mm) was used for processing. Cranial MRI was performed with an imager operating at 1.5 Tesla. Spin-echo TI- and T2-weighted and FLAIR slices were obtained for each individual.Results: In all of the five diseased children we observed pathologic findings both on MRI and Tc-99m HMPAO SPECT. The findings on MRI were mainly features of cerebral and cerebellar atrophy and the observations on Tc-99m HMPAO SPECT were regional perfusion abnormalities. We observed some structural abnormalities on MRI in four of the parents and two of the four healthy siblings. We also noted perfusion abnormalities on Tc-99m HMPAO SPECT in two of the parents and two of the healthy siblings.Conclusion: Because the disease is inherited in an autosomal recessive manner, the parents and the healthy siblings were not supposed to exhibit any demonstrable brain lesions, but the brain perfusion SPECT and MRI examinations clearly revealed multiple lesions in some of the parents and healthy siblings. Detailed neurological examinations of these individuals were normal except for one apparently healthy sibling (EY). Follow-up imaging of these families is being undertaken and further studies are essential in understanding the pathogenesis and genetics of neuronal ceroid-lipofuscinoses.


Türk Patoloji Dergisi | 2011

Factors predicting non-sentinel lymph node involvement in sentinel node positive breast carcinoma.

Merih Guray Durak; Bulent Akansu; Mehmet Mustafa Akin; Ali Ibrahim Sevinc; Mehmet Ali Kocdor; Serdar Saydam; Omer Harmancioglu; Hulya Ellidokuz; Recep Bekis; Tülay Canda

OBJECTIVE In routine practice, axillary lymph node dissection is performed in early invasive breast cancer patients with positive sentinel node biopsy. However, sentinel node is the only involved axillary node in 40-70% of patients, and determining factors that predict axillary non-sentinel node involvement will therefore prevent unnecessary axillary lymph node dissection and decrease morbidity. MATERIAL AND METHOD In this study, 119 invasive breast cancer patients with sentinel node metastasis who underwent axillary lymph node dissection between 1998-2009 at our institution were studied. Primary tumor characteristics and features of the metastatic tumors in sentinel nodes, such as microanatomic location, size of metastasis, and the ratio of metastatic tumor area to the total sentinel node area were evaluated. Students t-test and multivariate logistic regression were used for statistical analysis. RESULTS The mean age of the patients was 50.7 years (28-80). Forty-three patients (36%) had invasive ductal and 25 patients (21%) had invasive lobular carcinoma. Most of the patients had either pT1 (44%) or pT2 (54%) tumors. Fifty-four patients (45%) had no further positive nodes in the axilla. The metastatic deposits in the sentinel node were subcapsular in 16 patients (13%). The percent area of sentinel node occupied by tumor (p < 0.001), number of sentinel nodes (p=0.041), and microanatomic location of metastatic tumor (p=0.002) were significantly associated with non-sentinel node metastasis in univariate analysis. The percent area of sentinel node occupied by tumor (p < 0.001) and number of sentinel nodes (p=0.033) remained significantly associated with non-sentinel node involvement in multivariate analysis. CONCLUSION In patients with invasive breast cancer and positive sentinel node, area percent of sentinel node occupied by tumor, and the number of sentinel nodes removed are independently predictive of non-sentinel node involvement.


Acta Chirurgica Belgica | 2010

Success of Minimally Invasive Single-Gland Exploration Using the Quick Intraoperative Parathyroid Assay

Ali Ibrahim Sevinc; Z.S. Derici; Recep Bekis; Tülay Canda; Mehmet Ali Kocdor; Serdar Saydam; Omer Harmancioglu

Abstract Objective: Using accurate localization techniques and the quick intra-operative parathyroid assay (QPTH), surgery for primary hyperparathyroidism due to a solitary adenoma has moved from the traditional wide bilateral neck exploration to more limited approaches such as minimally invasive single-gland exploration (MISGE) and minimally invasive radio-guided parathyroidectomy (MIRP). This study investigated whether the MISGE could take the place of MIRP with the help of the QPTH. Design: From 2007 to 2009, 56 patients with primary hyperparathyroidism were studied. All patients were pre-opera-tively investigated by imaging techniques to improve the pre-operative determination of adenomas. Twenty-five patients were in the MIRP group and 31 in the MISGE group. QPTH was routinely measured; a 50% reduction in the QPTH level indicated complete excision. Results: There were no differences in the complication rates, surgical time, anaesthesia time or mean length of hospital stay between the groups. However, total hospital charges were more favourable in the MISGE group with a mean saving of


Clinical Nuclear Medicine | 2003

Technetium-99m tetrofosmin uptake in insular thyroid carcinoma. A comparison with iodine-131.

Berna Degirmenci; Aysel Aydin; Abdurrahman Comlekci; Ozhan Ozdogan; Recep Bekis

400 per case. Conclusion: This study demonstrates that with the additon of the QPTH, MISGE can be performed as a quick and reliable procedure in correct adenoma removal instead of MIRP. Moreover MISGE achieves the optimal time interval between injection and exploration, reduces the radiation exposure of both patient and surgeon, decreases the cost, and decreases usage of pre-operative imaging and intra-operative equipment.

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Hatice Durak

Dokuz Eylül University

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Emel Ada

Dokuz Eylül University

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