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Featured researches published by Ali Fuat Yapar.


Annals of Nuclear Medicine | 2008

Preoperative evaluation of hyperparathyroidism: the role of dual-phase parathyroid scintigraphy and ultrasound imaging

Aysun Sukan; Mehmet Reyhan; Mehmet Aydin; Ali Fuat Yapar; Yasar Sert; Tuba Canpolat; Ayse Aktas

ObjectiveThe aim of this study was to evaluate the efficacy of dual-phase 99mTc-methoxyisobutylnitrile (MIBI) parathyroid scintigraphy (PS) and ultrasound (US) in primary (pHPT) and secondary (sHPT) hyperparathyroidism.MethodsA total of 69 patients (mean age 47 ± 16; age range 14–79 years), including 19 patients with sHPT were enrolled in this study. Preoperative serum intact parathyroid hormone (iPTH) levels, calcium (Ca), phosphate (P), alkaline phosphatase, and 24-h urinary-free Ca measurements were obtained. Concomitant thyroid pathology was also recorded.ResultsHistopathology revealed 30 solitary adenomas and 71 hyperplastic glands in 55 patients. The remaining patients’ histopathology revealed normal parathyroid, thyroid, or lymph nodes. The sensitivities of MIBI and US in pHPT were 70% and 60%, respectively. It was 60% for both procedures in sHPT. The overall sensitivity of combined US + MIBI in pHPT and sHPT was 81% and 71%, respectively. The overall specificity of MIBI and US was 87% and 91%; positive predictive value (PPV) was 94% and 92%, respectively. MIBI and US identified the parathyroid pathology in 92% and 85% of patients in the non-concomitant thyroid disease group, and in 53% and 47% of patients in the concomitant thyroid disease group, respectively. The weight of the gland between primary and secondary hyperparathyroidism did not reveal a significant difference (P = 0.4). Significant differences were found with respect to age, PTH, Ca, and P levels between the pHPT and sHPT (P < 0.001). Intact PTH levels showed significant differences between MIBI positive and negative patients (P = 0.013), and also US positive and negative patients (P = 0.012). A significant negative correlation was found between iPTH and Ca at sHPT (P < 0.001).ConclusionsThe concomitancy of thyroid disease greatly influences scintigraphic and ultrasonographic detection of parathyroid pathology in pHPT and sHPT. The combination of MIBI and US appears promising for localizing parathyroid pathology in patients with both primary and secondary hyperparathyroidism. The concordance rate is high together with a lower chance of missing concomitant thyroid pathology, which might alter the surgical approach.


BMC Gastroenterology | 2011

Predictive value of metabolic 18FDG-PET response on outcomes in patients with locally advanced pancreatic carcinoma treated with definitive concurrent chemoradiotherapy

Erkan Topkan; Cem Parlak; Ayse Kotek; Ali Fuat Yapar; Berrin Pehlivan

BackgroundWe aimed to study the predictive value of combined 18F-fluoro-deoxy-D-glucose positron emission tomography and computerized tomography (FDG-PET-CT), on outcomes in locally advanced pancreatic carcinoma (LAPC) patients treated with concurrent chemoradiotherapy (C-CRT).MethodsThirty-two unresectable LAPC patients received 50.4 Gy (1.8 Gy/fr) of RT and concurrent 5-FU followed by 4 to 6 cycles of gemcitabine consolidation. Response was evaluated by FDG-PET-CT at post-C-CRT 12-week. Patients were stratified into two groups according to the median difference between pre- and post-treatment maximum standard uptake values (SUVmax) as an indicator of response for comparative analysis.ResultsAt a median follow-up of 16.1 months, 16 (50.0%) patients experienced local/regional failures, 6 of which were detected on the first follow-up FDG-PET-CT. There were no marginal or isolated regional failures. Median pre- and post-treatment SUVmax and median difference were 14.5, 3.9, and -63.7%, respectively. Median overall survival (OS), progression-free survival (PFS), and local-regional progression-free survival (LRPFS) were 14.5, 7.3, and 10.3 months, respectively. Median OS, PFS, and LRPFS for those with greater (N = 16) versus lesser (N = 16) SUVmax change were 17.0 versus 9.8 (p = 0.001), 8.4 versus 3.8 (p = 0.005), and 12.3 versus 6.9 months (p = 0.02), respectively. On multivariate analysis, SUVmax difference was predictive of OS, PFS, and LRPFS, independent of existing covariates.ConclusionsSignificantly higher OS, PFS, and LRPFS in patients with greater SUVmax difference suggest that FDG-PET-CT-based metabolic response assessment is an independent predictor of clinical outcomes in LAPC patients treated with definitive C-CRT.


Infectious Diseases in Clinical Practice | 2007

Prospective Evaluation of 140 Patients With Brucellosis in the Southern Region of Turkey

Lutfu Savas; Yusuf Onlen; Nazan Savaş; Ali Fuat Yapar; Mehmet Aydin; Onder Tugal

The aim of this study was to asses the epidemiological, clinical, and laboratory characteristics of brucellosis in Adana region, Turkey. In this prospective study, a total of 140 patients with brucellosis were investigated in terms of spread of infection; seasonal, age, and sex distribution; clinical and laboratory characteristics; depression and anxiety rates; relapse rates; and response to different treatment combinations. One hundred two patients (72.9%) were female, and 38 patients (27.1%) were male; mean age was 45.81 ± 15.62 years, ranging from 2 to 77 years. Twenty-five patients (17.8%) had history of contact with animals, and 31 patients (22.1%) had history of consumption of raw milk and/or its products. The highest seasonal distribution was observed during summer. Malaise (95.0%), sweating (85.7%), and arthralgia (85.0%) were the major presenting symptoms. The most common physical examination findings were fever (52.9%), hepatomegaly (20.7%), and splenomegaly (12.1%). Osteoarticular involvement, orchitis, and iridocyclitis were observed in 64.9%, 38.0% (of male patients), and 0.7% of the patients, respectively. Scintigraphy was performed for 114 patients who have focal joint and bone complaints and findings. Beck Depression Inventory and State-Trait Anxiety Inventory testing were applied to 98 patients with brucellosis, and depression was observed in 37.8% of these patients. The total point of State Anxiety Inventory testing was 46.21 ± 12.87, and the total point of Trait Anxiety Inventory testing was 46.98 ± 10.11. Either the depression rates or points of State Anxiety Inventory testing and Trait Anxiety Inventory testing in patients with brucellosis were statistically higher than in the control group. In 134 patients, initial standard tube agglutination testing titer was 1/160 or more. Brucella melitensis was found positive in 22 patients. Relapse rate was 3.5%. Brucellosis continues to be a health problem in countries where consumption of unpasteurized dairy products and stockbreeding are common.


Gynecologic Oncology | 2015

Prognostic value of 18F-fluorodeoxyglucose uptake in pelvic lymph nodes in patients with cervical cancer treated with definitive chemoradiotherapy

Cem Onal; Ozan Cem Guler; Mehmet Reyhan; Ali Fuat Yapar

PURPOSE To evaluate the prognostic significance of the maximum standardized uptake (SUVmax) value for pelvic lymph nodes in patients with cervical cancer and its impact on treatment response, disease control, and survival. METHODS Ninety-three patients with pelvic or para-aortic metastasis detected by PET/CT and treated with definitive chemoradiotherapy were evaluated. The impact of pelvic lymph node SUVmax on prognostic factors and treatment outcomes was assessed. RESULTS The size and SUVmax of pelvic lymph nodes were significantly correlated (r=0.859; p<0.001). Patients with pelvic and para-aortic lymph node metastases had significantly higher SUVmax values for both primary tumor (23.4±9.2 vs. 18.5±7.3; p=0.01) and pelvic lymph nodes (11.4±4.6 vs. 7.4±3.8; p=0.001). Patients with pelvic lymph node SUVmax≥7.5 had significantly higher primary tumor SUVmax, larger pelvic lymph nodes, higher rates of para-aortic lymph node metastasis, and lower post-therapy complete response rates. Overall survival (OS) and disease-free survival (DFS) rates were significantly higher in patients with SUVmax<7.5 compared to patients with SUVmax≥7.5. In a multivariate analysis, pelvic lymph node SUVmax and post-therapy metabolic response were significant prognostic factors for both OS and DFS for all patients, but no significant prognostic factors were found in pelvic lymph node metastasis only. CONCLUSIONS Patients with highly FDG-avid pelvic lymph nodes have a higher risk of disease recurrence with worse survival. Identification of these patients may assist in the evaluation of the clinical benefits of additional treatments.


Cancer Imaging | 2013

FDG-PET/CT-based restaging may alter initial management decisions and clinical outcomes in patients with locally advanced pancreatic carcinoma planned to undergo chemoradiotherapy.

Erkan Topkan; Cem Parlak; Ali Fuat Yapar

Abstract The impact of [18F]fluorodeoxyglucose-positron emission tomography (PET)/computed tomography (CT) restaging on management decisions and outcomes in patients with locally advanced pancreatic carcinoma (LAPC) scheduled for concurrent chemoradiotherapy (CRT) is examined. Seventy-one consecutive patients with conventionally staged LAPC were restaged with PET/CT before CRT, and were categorized into non-metastatic (M0) and metastatic (M1) groups. M0 patients received 50.4 Gy CRT with 5-fluorouracil followed by maintenance gemcitabine, whereas M1 patients received chemotherapy immediately or after palliative radiotherapy. In 19 patients (26.8%), PET/CT restaging showed distant metastases not detected by conventional staging. PET/CT restaging of M0 patients showed additional regional lymph nodes in 3 patients and tumors larger than CT-defined borders in 4. PET/CT therefore altered or revised initial management decisions in 26 (36.6%) patients. At median follow-up times of 11.3, 14.5, and 6.2 months for the entire cohort and the M0 and M1 cohorts, respectively, median overall survival was 16.1, 11.4, and 6.2 months, respectively; median locoregional progression-free survival was 9.9, 7.8, and 3.4 months, respectively; and median progression-free survival was 7.4, 5.1, and 2.5 months, respectively (P < 0.05 each). These findings suggest that PET/CT-based restaging may help select patients suitable for CRT, sparing those with metastases from futile radical protocols, and increasing the accuracy of estimated survival.


Clinical Nuclear Medicine | 2016

Is PET/CT Necessary in the Management of Early Breast Cancer?

Gül Nihal Nursal; Tarik Zafer Nursal; Huseyin Ozgur Aytac; Bermal Hasbay; Nese Torun; Mehmet Reyhan; Ali Fuat Yapar

Purpose Advanced imaging methods in early breast cancers are not recommended before surgery. In contrast to the accepted guidelines, some recent studies have shown some benefits with the use of PET/CT in early-stage breast cancer. In this study, we aimed to document the efficacy of PET/CT in detection of distant metastasis as well as other primary cancers. Patients and Methods In this retrospective study, we reviewed the records of all women patients diagnosed with early breast cancer between March 2012 and December 2014. Besides demographics, we recorded the clinical TNM stage, histology of the tumor, and hormone receptor status. As PET/CT imaging is a routine procedure in our center for early breast cancer, tumor size, lymph node status, distant metastasis, and possible other primary malignancies detected by PET/CT were also recorded. Results Of the 419 women included in the study, 24.8% were clinically staged as stage I while the rest were stage II. Distant metastases were detected in 42 patients (10%). The yield of PET/CT in detecting metastasis was significant in stage II patients compared with stage I patients (12.4% vs 2.9%). In subgroup analysis of stage II patients, the performance of PET/CT in detecting metastasis was still evident in stage IIA patients (9.5%). In logistic regression analysis of the significant and near-significant factors (as detected by univariate analysis) effecting PET/CT detected distant metastasis, only nodal status (P = 0.053) was found to be significant. Conclusions We suggest the use of PET/CT in investigating metastasis in axilla positive and clinically stage II early breast cancer patients.


Clinical Nuclear Medicine | 2011

Diffuse splenic F-18 FDG uptake in visceral leishmaniasis.

Ali Fuat Yapar; Mehmet Reyhan; Nazim Emrah Kocer; Mehmet Aydin; Gül Nihal Nursal

A 51-year-old woman had splenomegaly and enlarged multiple splenic hilar lymph nodes. The patient was referred to our department for F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) evaluation to determine the metabolic activity of lymph nodes and define a biopsy site. PET/CT images showed diffuse increased FDG uptake in an enlarged spleen and hypermetabolic splenic hilar lymph nodes. The metabolic activity in bone marrow also seemed diffusely increased. After splenectomy, histopathologic analysis showed the growth of Leishmania amastigotes in splenic tissue, and bone marrow biopsy did not reveal any significant pathology but only mild hypercellularity.


Case reports in endocrinology | 2013

A case of inoperable malignant insulinoma with resistant hypoglycemia who experienced the most significant clinical improvement with everolimus.

Emre Bozkirli; Okan Bakiner; Huseyin Abali; Çağatay Andıç; Ali Fuat Yapar; Fazilet Kayaselcuk; Eda Ertorer

Metastatic insulinomas may sometimes present with recurrent life-threatening hypoglycemia episodes. Such patients usually fail to respond to various therapeutic agents which causes constant dextrose infusion requirement. Herein, we present a resistant case of inoperable malignant insulinoma who was treated with many therapeutic agents and interventions including somatostatin analogues, Yttrium-90 radioembolization, everolimus, radiotherapy, and chemoembolization. Close blood sugar monitorization during these therapies showed the most favourable response with everolimus. Everolimus treatment resulted in rapid improvement of hypoglycemia episodes, letting us discontinue dextrose infusion and discharge the patient. However, experience with everolimus in such patients is still limited, and more precise data can be obtained with the increasing use of this agent for neuroendocrine tumours.


Onkologie | 2013

Comparison of Computed Tomography- and Positron Emission Tomography-Based Radiotherapy Planning in Cholangiocarcinoma

Cem Onal; Savas Topuk; Ali Fuat Yapar; Melek Nur Yavuz; Erkan Topkan; A. Aydin Yavuz

Introduction: The aim of this study was to compare computed tomography (CT)- and positron emission tomography (PET)/CT-based gross tumor volume (GTV) delineation and its subsequent expansion to the planning target volume (PTV), and to analyze the resultant doses of 3-dimensional conformal radiotherapy (3D-CRT) to critical organs. Methods: 15 patients with unresectable extrahepatic cholangiocarcinoma (EHCC) were enrolled into this study. PTVCT-based plans were initially made, and then PTVPET-CT-based plans were created using the same beam angles and isocenter. The dosimetric parameters analyzed included GTVCT, PTVCT, GTVPET-CT and PTVPET-CT. Prescribed and delivered radiation doses to target volumes and delineated organs at risk were also compared. Results: Mean GTV and PTV were significantly reduced in the PET/CT-based plan compared to the CT-based plan; the mean reductions of GTV and PTV were 28.7% and 15.2%, respectively. The mean value for GTVPET/GTVCT mismatch was 49.5 ± 28.9%, and that for GTVCT/GTVPET was 95.9 ± 19.5%. The mean value for PTVPET-CT/PTVCT mismatch was 21.9 ± 7.0% and that for PTVCT/PTVPET-CT was 39.1 ± 9.2%. Liver doses were significantly reduced (17.1%) in the PET/CT-based plan compared to the CT-based plan; the doses received by at least 30% and 50% of the liver were 30.0%, and 27.3%, respectively. Conclusion: The potential benefit of PET/CT is the reduction in geographic misses and regional treatment failures associated with CT-based planning.


Clinical Nuclear Medicine | 2007

Gated SPECT findings revealing diastolic dysfunction in acute hypothyroidism.

Mehmet Aydin; Mehmet Reyhan; Aysun Sukan; Ali Fuat Yapar; Aktas A

Purpose: The purpose of this study was to assess left ventricular (LV) function by gated SPECT in acute hypothyroidism. Methods: Thirty-eight acute hypothyroid patients without any cardiac disease and 40 healthy controls underwent gated SPECT at rest. Fourteen patients had a second examination during thyroxine replacement therapy. Gated SPECT was performed using Tc-99m sestamibi with 16 frames per cardiac cycle. The LV end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), peak ejection rate (PER), peak filling rate (PFR), and time to peak filling (TTPF) were measured by quantitative gated SPECT (QGS). Systolic wall thickening/motion was determined in 5 myocardial segments. Results: Hypothyroid patients exhibited a decrease in PFR (222 ± 52 EDV/s) and prolongation of TTPF (194 ± 32 msec) as compared with controls (247 ± 41 EDV/s and 179 ± 17 msec, respectively; P < 0.05). During thyroxine therapy, the mean values for EDV (74 ± 21 mL) and PFR (265 ± 64 EDV/s) increased significantly in 14 follow-up patients (pretreatment values 67 ± 18 mL and 219 ± 50 EDV/s, respectively; P < 0.05). A significant difference was detected in the mean TTPF between the thyroxine group and the controls (195 ± 35 msec vs 179 ± 17 msec; P < 0.05). No significant differences were found in wall thickening and motion values (P > 0.05). Conclusion: Gated SPECT findings revealed diastolic dysfunction as indicated by a decrease in PFR and a prolongation in TTPF in patients with acute hypothyroidism.

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