Browsing by Author "Reyhan, Mehmet"

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A Case of a Man With Isolated Breast Metastasis From Lung Adenocarcinoma Incidentally Detected by FDG PET/CT
(2016) Erhamamci, Seval; Reyhan, Mehmet; Canpolat, Tuba; Nursal, Gul Nihal; Yapar, Ali Fuat; https://orcid.org/0000-0001-8550-3368; https://orcid.org/0000-0002-5302-4386; https://orcid.org/0000-0003-1715-4180; 26562574; AAJ-5242-2021; AAK-8107-2021; R-3735-2016; AAI-8973-2021
Breast metastases from an extramammary primary tumor are very rare, particularly in men. In this study, we present a case of a 74-year-old man with isolated breast metastasis from lung adenocarcinoma as an incidental finding on PET/CT and diagnosed concomitantly with the primary tumor. Detection of isolated incidental metastatic lesions in the breast on PET/CT imaging has a significant clinical impact on patients with known malignant disease due to change of disease stage, management, and also treatment method.
A Case of Primary Colon Carcinoma Demonstrated by FDG PET/CT Imaging After Detection of a Solitary Brain Metastasis
(2015) Erhamamci, Seval; Reyhan, Mehmet; Nursal, Gul Nıhal; Torun, Nese; Yapar, Ali Fuat
The detection of brain metastases as the initial manifestation of colorectal carcinoma without liver or lung involvement is extremely rare. Herein we present a case of a 52-year-old male patient with an unusual presentation of colon cancer, with primary lesions demonstrated by fluorine- 18-labeled fluorodeoxyglucose (FDG) Positron-emission tomography/computed tomography (PET/CT) after detection of a solitary brain metastasis. Brain CT images revealed a brain tumor. Histopathologic evaluation indicated metastatic poorly differentiated adenocarcinoma, while his physical examination was normal. The PET/CT revealed abnormal intense FDG uptake in the right parietal region and in descending colon, with no other abnormal FDG uptake elsewhere in the body. The histopathologic diagnosis of the descending colon lesion revealed moderately differentiated adenocarcinoma. This case indicates that FDG PET/CT imaging may have a positive impact on the evaluation of patients with brain metastasis from an unknown primary.
Choroidal Metastasis of Papillary Thyroid Carcinoma Demonstrated on SPECT-CT
(2016) Torun, Nese; Reyhan, Mehmet; Yapar, Ali Fuat; Karatas, Muge; https://orcid.org/0000-0002-5597-676X; https://orcid.org/0000-0001-8550-3368; https://orcid.org/0000-0003-1715-4180; 26825205; AAE-2718-2021; AAJ-5242-2021; AAI-8973-2021
We report a 68-year-old woman with papillary thyroid carcinoma metastasizing to choroid. The choroid metastasis was diagnosed with SPECT-CT and then was treated with high-dose radioactive iodine therapy.
Clinical parameters and nomograms for predicting lymph node metastasis detected with Ga-68-PSMA-PET/CT in prostate cancer patients candidate to definitive radiotherapy
(2021) Onal, Cem; Ozyigit, Gokhan; Oymak, Ezgi; Guler, Ozan Cem; Hurmuz, Pervin; Tilki, Burak; Reyhan, Mehmet; Tuncel, Murat; Akyol, Fadil; 0000-0002-2742-9021; 33949694; D-5195-2014
Background Defining the extent of disease spread with imaging modalities is crucial for therapeutic decision-making and definition of treatment. This study aimed to investigate whether clinical parameters and nomograms predict prostate-specific membrane antigen (PSMA)-positive lymph nodes in treatment-naive nonmetastatic prostate cancer (PC) patients. Materials and Methods The clinical data of 443 PC patients (83.3% high-risk and 16.7% intermediate-risk) were retrospectively analyzed. Receiver operating characteristic (ROC) curves with areas under the curve (AUC) were generated to evaluate the accuracy of clinical parameters (prostate-specific antigen [PSA], T stage, Gleason score [GS], International Society of Urological Pathology [ISUP] grade) and nomograms (Roach formula [RF], Yale formula [YF], and a new formula [NF]) in predicting lymph node metastasis. The AUCs of the various parameters and clinical nomograms were compared using ROC and precision-recall (PR) curves. Results A total of 288 lymph node metastases were identified in 121 patients (27.3%) using Ga-68-PSMA-11-positron emission tomography (PET)/computed tomography (CT). Most PSMA-avid lymph node metastases occurred in external or internal iliac lymph nodes (142; 49.3%). Clinical T stage, PSA, GS, and ISUP grade were significantly associated with PSMA-positive lymph nodes according to univariate logistic regression analysis. The PSMA-positive lymph nodes were more frequently detected in patients with PSA >20 ng/ml, GS >= 7 or high risk disease compared to their counterparts. The clinical T stage, serum PSA level, GS, and ISUP grade showed similar accuracy in predicting PSMA-positive metastasis, with AUC values ranging from 0.675 to 0.704. The median risks for PSMA-positive lymph nodes according to the RF, YF, and NF were 31.3% (range: 12.3%-100%), 22.3% (range: 4.7%-100%), and 40.5% (range: 12.3%-100%), respectively. The AUC values generated from ROC and PR curve analyses were similar for all clinical nomograms, although the RF and YF had higher accuracy compared to NF. Conclusion The clinical T stage, PSA, GS, and ISUP grade are independent predictors of PSMA-positive lymph nodes. The RF and YF can be used to identify patients who can benefit from Ga-68-PSMA-11 PET/CT for the detection of lymph node metastasis. Together with nomograms, Ga-68-PSMA-11 PET/CT images help to localize PSMA-positive lymph node metastases and can thus assist in surgery and radiotherapy planning.
Diffuse Metastasis of Malignant Melanoma
(2015) Erhamamci, Seval; Reyhan, Mehmet
The effect of androgen deprivation therapy on 68GA-PSMA-tracer uptake in nonmetastatic prostate cancer patients
(2020) Cem, Onal; Guler, Ozan Cem; Torun, Nese; Reyhan, Mehmet; Yapar, Ali Fuat; 0000-0002-5597-676X; 0000-0003-1715-4180; 0000-0001-8550-3368; 0000-0001-6908-3412; AAE-2718-2021; AAI-8973-2021; AAJ-5242-2021; AAC-5654-2020
The effect of androgen deprivation therapy on Ga-68-PSMA tracer uptake in non-metastatic prostate cancer patients
(2020) Onal, Cem; Guler, Ozan Cem; Torun, Nese; Reyhan, Mehmet; Yapar, Ali Fuat; 0000-0002-5597-676X; 0000-0001-8550-3368; 0000-0003-1715-4180; 0000-0001-6908-3412; 0000-0002-2742-9021; 31732768; AAE-2718-2021; AAJ-5242-2021; AAI-8973-2021; AAC-5654-2020; D-5195-2014
Purpose To evaluate the effect of neoadjuvant androgen deprivation treatment (ADT) on prostate-specific membrane antigen (PSMA) tracer uptake demonstrated in Ga-68-PSMA-positron emission tomography (PET/CT) in non-metastatic hormone-naive prostate cancer (PC) patients. Materials and methods The clinical data of 108 PC patients who received neoadjuvant ADT were retrospectively analyzed. All patients had a baseline Ga-68-PSMA-PET/CT scan, and a second scan was delivered median of 2.9 months after the initiation of ADT. The maximum standardized uptake value (SUVmax) of primary tumor (SUVp) and metastatic lymph nodes (SUVln) as well as PSA response were assessed between pre- and post-ADT Ga-68-PSMA-PET/CT scans. Results There were significant decreases in posttreatment serum PSA, SUVp, and SUVln. A decrease in SUVp was seen in 91 patients (84%) with a median value of 66% (range, 5-100%), while 17 patients (16%) had no change in or an increase in PSMA tracer uptake with a median value of 24% (range, 0-198%). Patients with Gleason score (GS) of 7 had significantly higher metabolic response rates compared to other patients. The disease progression was significantly higher only in patients with GS > 7 disease compared to GS 7 disease. The PSA response to ADT was the lowest in patients with ISUP high-grade tumors. A total of 16 patients (15%) had progressive disease, and in 9 patients (8%), radiotherapy decisions were modified according to posttreatment Ga-68-PSMA-PET/CT scans. Conclusions The current study includes the largest number of patients analyzed to date and demonstrates that ADT causes a significant decrease in serum PSA values and SUVp and SUVln. The authors demonstrate that Ga-68-PSMA-PET/CT may be used as a quantitative imaging modality after neoadjuvant ADT in hormone-naive non-metastatic PC patients.
The effect of sodium iodide symporter protein on ablation success in patients with differentiated thyroid cancer
(2022) Mutevelizade, Gozde; Kocer, Nazim Emrah; Reyhan, Mehmet; https://orcid.org/0000-0001-8550-3368; 36214955; AAJ-5242-2021
Objective This study aimed to investigate immunohistochemical staining of sodium iodide symporter (NIS) and its effect on response to I-131 therapy in differentiated thyroid carcinoma patients. Methods We evaluated NIS expression, the intracellular distribution of NIS, iodine-131 uptake in residual tissues on post-ablation I-131 whole body scan, and the ablation status after 100 mCi I-131 therapy. We also investigated NIS expression and localization in tumoral paraffin-embedded tissues. Results In this retrospective study, 35 patients (mean age 44.17 +/- 12.9 years, 27 female, 8 male) were studied. Twenty-one of these patients responded to radioiodine therapy, and 14 did not. NIS expression and iodine-131 uptake in residual tissues post-ablation I-131 whole body scan were not statistically significant. When we compared the patients who responded to radioiodine therapy and the poor responder group, NIS expression and iodine-131 uptake in residual tissues did not demonstrate statistically significant difference [(p = 0.308) (p = 0.985) respectively]. 47.6% of the patients in the successful ablation group and 85.7% in the unsuccessful ablation group had intracellular NIS immunostaining. The difference was not statistically significant (p = 0.139). 52.4% of the patients in the successful ablation group and 7% in the unsuccessful ablation group had NIS immunostaining at the basolateral membrane. The difference was statistically significant (p < 0.05). Conclusions In conclusion, we did not find any significant difference between successful and unsuccessful ablation groups in terms of NIS expression; however, we concluded that the intracellular (cytoplasmic) localization of NIS is one of the leading causes of ablation failure regardless of NIS expression in DTC patients.
Elastofibroma Dorsi Incidentally Detected by 18F-FDG PET/CT Imaging
(2015) Erhamamci, Seval; Reyhan, Mehmet; Nursal, Gul Nihal; Torun, Nese; Yapar, Ali Fuat; Findikcioglu, Alper; Canpolat, Tuba; 0000-0003-1715-4180; 0000-0002-5597-676X; 0000-0002-5302-4386; 0000-0001-8550-3368; 25666569; AAI-8973-2021; AAE-2718-2021; R-3735-2016; AFT-2303-2022; AAK-8107-2021; AAJ-5242-2021
Elastofibroma dorsi (ED) is a rare pseudotumor of the soft tissues that can also show 18F-fluorodeoxyglucose (F-18-FDG) uptake on positron emission tomography combined with computed tomography (PET/CT) imaging. The aim of this retrospectively study was to describe the metabolic characteristics of ED incidentally detected by F-18-FDG PET/CT imaging. Between November 2009 and August 2013 at our institution, 10,350 consecutive PET/CT examinations were retrospectively investigated. In 176 of these patients, ED was recorded as an incidental finding. Fifty-five of 176 patients also had follow-up scans after chemoradiotherapy. A total of 231 scans with ED in 176 patients were identified. To determine the metabolic activity of ED, the maximum standardized uptake value (SUVmax) was calculated semiquantitatively. For measurement size of ED, the longest axis of transaxial CT images was used. Seven of the 176 patients underwent surgery due to suspected metastases and/or invasion of primary malignancy and/or symptoms or incidental during surgery. The prevalence of ED in our series was 1.7 %. The lesions were located in the subscapular region in all patients, except in one case with a lesion in the infrascapular region. A total of 419 ED lesions in 231 scan of 176 patients were evaluated. Mean +/- A SD SUVmax and long axis values for these 419 lesions were 2.31 +/- A 0.61 (range 1.0-4.30) and 56.78 +/- A 17.01 mm (range 19-112 mm), respectively. Of these 176 patients, 141 (80.1 %) had bilateral lesions and 35 (19.9 %) had unilateral lesions. There were statistically significant differences in the SUVmax and long axis values between the right and left side in the bilateral lesions (p = 0.001). No significant differences in the SUVmax and long axis values of the lesion were found between pre- and posttreatment in the patients with follow-up scans. Elastofibroma dorsi located in the scapular region is usually bilateral, asymmetric and with mild or moderate metabolic activity on PET/CT imaging. In addition, the metabolic activity and size of ED remained stable after chemoradiotherapy. Awareness of these metabolic characteristics of ED is important for preventing misinterpretation during F-18-FDG PET/CT studies.
Evaluation of cyclic direct radionuclide cystography findings with DMSA scintigraphy results in children with a prior diagnosis of vesicoureteral reflux
(2019) Torun, Nese; Aktas, Ayse; Reyhan, Mehmet; Yapar, A. Fuat; Nursal, G. Nihal; 0000-0003-0149-2265; 30741838
Objectives Direct radionuclide cystography (DRC) with cyclic imaging is a sensitive method used for the detection of vesicoureteral reflux (VUR). Radionuclide cystography is generally recommended for follow-up evaluation of VUR. The aim of this study was to evaluate cyclic DRC with DMSA scan results during the follow-up period in children with a prior diagnosis of VUR. Patients and methods DRC findings of 85 children with VUR were evaluated together with DMSA findings during follow-up. VUR grade was classified anatomically as grades I, II, and III reflux. Reflux grades of II and III were regarded as high-grade reflux. Reflux was also graded functionally as transient and continuous on the basis of the presence of reflux on either filling or voiding phases (transient) or both phases (continuous) of at least one cycle. Results Among 85 children, 32 (38%) exhibited reflux. In five patients, reflux was observed on both sides, and a total of 37 refluxing units (RUs) were evaluated. According to the highest grade attained in either cycle, 31 (84%) units had grade II, five had grade I and one had grade III reflux. Reflux was continuous in 23 (62%) and transient in 14 (38%) RUs. The incidence of an abnormal scan result was higher in continuous reflux group (78%) than in high-grade anatomic reflux group (59%). The addition of a second cycle resulted in the diagnosis of continuous reflux in six (26%) more RUs. DMSA scan findings correlated significantly with functional reflux classification (P<0.05), but not with anatomic reflux classification (P>0.05). Conclusion Functional classification of VUR into continuous and transient reflux resulted in higher correlation with DMSA scan findings compared with anatomic reflux grading in follow-up patients with VUR. Cyclic imaging contributed to continuous reflux diagnosis. The significance of functional information obtained from cyclic DRC in initial diagnostic workup, management, and follow-up of children with urinary tract infection needs to be determined with further studies.
F-18-FDG PET/CT Imaging in an Unusual Case of Cutaneous Melanoma Arising From Congenital Melanocytic Nevus in a Two-year-old Girl
(2021) Erhamamci, Seval; Reyhan, Mehmet; Bal, Nebil; Torun, Nese; Yapar, Ali Fuat; 0000-0001-5016-4650; 0000-0001-8550-3368; 34082516; AAJ-5242-2021
Fluorodeoxyglucose-positron emission tomography/computed tomography imaging of squamous cell carcinoma arising in a meningomyeloceled
(2016) Erhamamci, Seval; Reyhan, Mehmet; Bal, Nebil; 26701228
Focal 99mTc-DMSA Uptake in Lung Parenchyma Without Structural Alterations on SPECT/CT
(2015) Nursal, Gul Nihal; Reyhan, Mehmet; Yapar, Ali Fuat; 0000-0003-1715-4180; 0000-0001-8550-3368; 0000-0002-5302-4386; 26053717; AAI-8973-2021; AAJ-5242-2021; R-3735-2016
Static renal scintigraphy with Tc-99m-DMSA is commonly used for the evaluation of renal morphology and function. Extrarenal uptake of Tc-99m-DMSA is a rare finding described previously on sites such as bone metastasis, hemangioma, and splenic amyloidosis. We report a case with Tc-99m-DMSA activity in the lungs.
Gigant Malign Germ Cell Tumor Occured in Intraabdominal Undescended Testis
(2015) Reyhan, Mehmet; Guvel, Sezgin; Yapar, Ali Fuat; 0000-0001-6534-9981; 0000-0003-1715-4180; 0000-0001-8550-3368; AAL-4363-2021; AAI-8973-2021; AAJ-5242-2021
Hounsfield unit value has null effect on thyroid nodules at F-18-FDG PET/CT scans
(2018) Haydedeoglu, Filiz Eksi; Bagir, Gulay Simsek; Torun, Nese; Kocer, Emra H.; Reyhan, Mehmet; Ertorer, Melek Eda; 30304111
Objective: Detection rate of thyroid nodules is increasing with the use of new imaging modalities, especially in screening for malignancies. Positron emission tomography/computed tomography (PET/CT)-positive thyroid nodules should be differentiated for malignancy to avoid unnecessary operations and further follow-up. Most trials evaluate the role of SUVmax, but there is no definitive information about the utility of Hounsfield unit (HU) values for prediction of malignancy. This study aimed to evaluate the HU values beside SUVmax for detecting malignancy risk of PET/CT-positive thyroid nodules. Subjects and methods: Results of 98 cancer patients who had fine needle aspiration biopsy (FNAB) for thyroid nodules detected on PET/CT between January 2011 and December 2015 were assessed. The FNABs and surgical pathological results were recorded. Results: FNABs revealed benign results in 32 patients (32.7%), malignant in 18 (18.4%), non-diagnostic in 20 (20.4%), and indeterminate in 28 (28.5%). Twenty-four patients underwent thyroidectomy. The mean HU values were not significantly different in benign and malignant nodules (p = 0.73). However, the mean SUVmax was significantly higher (p < 0.001) in malignant ones. Area under curve (AUC) was 0.824 for SUVmax; the cut-off value was over 5.55 (p < 0.001), with 80% sensitivity, 84.5% specificity. Conclusions: Our current study demonstrated that HU value does not add any additional valuable information for discriminating between malignant and benign thyroid nodules. We also defined a SUVmax cut-off value of 5.55 for malignant potential of thyroid nodules detected on PET/CT.
Integration of 68Ga-PSMA-PET/CT in Radiotherapy Planning for Prostate Cancer Patients
(2019) Onal, Cem; Torun, Nese; Akyol, Fadil; Guler, Ozan Cem; Hurmuz, Pervin; Yildirim, Berna Akkus; Caglar, Meltem; Reyhan, Mehmet; Ozyigit, Gokhan; 0000-0001-6908-3412; 31283600
Purpose To assess the role of (68)Gallium-labeled-prostate-specific membrane antigen PET/CT (Ga-68-PSMA-PET/CT) in risk group definition and radiotherapy planning in the initially planned definitive radiotherapy (RT) for prostate cancer patients. Methods The clinical data of 191 prostate cancer patients treated with definitive intensity-modulated RT were retrospectively analyzed. All patients were initially staged with thoracoabdominal CT and bone scintigraphy, and the second staging was performed using Ga-68-PSMA-PET/CT. Both stages were evaluated for the decision making of RT and any change in RT target volumes. Results After staging with Ga-68-PSMA-PET/CT, 26 patients (13.6%) had risk group changes, 16 patients (8.4%) had an increase in risk group, and 10 patients (5.2%) had a decrease in risk group. Down-staging occurred in 22 patients (11.5%), and upstaging was observed in 30 patients (15.7%). A total of 26 patients (13.6%) had nodal stage changes. After the Ga-68-PSMA-PET/CT scans, the number of metastatic patient increased to 17 (8.9%), with 4 of them moving from oligo- to polymetastatic disease. An additional irradiation of pelvic lymphatics and metastatic site was performed in 13 patients (6.8%) and 6 patients (3.2%), respectively. The RT was aborted in 4 patients (2.1%) because of parenchymal or distant site metastasis observed in the Ga-68-PSMA-PET/CT. Conclusions We found that Ga-68-PSMA-PET/CT causes considerable migration in stage, risk group, and RT field arrangements, especially in high-risk patients regardless of the GS and baseline prostate-specific antigen values alone. Ga-68-PSMA-PET/CT seems to have a great influence on RT decision making in prostate cancer patients.
Is PET/CT Necessary in the Management of Early Breast Cancer?
(2016) Nursal, Gul Nihal; Nursal, Tarik Zafer; Aytac, Huseyin Ozgur; Hasbay, Bermal; Torun, Nese; Reyhan, Mehmet; Yapar, Ali Fuat; https://orcid.org/0000-0002-5302-4386; https://orcid.org/0000-0002-3583-9282; https://orcid.org/0000-0002-5597-676X; https://orcid.org/0000-0001-8550-3368; https://orcid.org/0000-0003-1715-4180; 26914560; R-3735-2016; IQV-1169-2023; AAJ-7913-2021; AAE-2718-2021; AAJ-5242-2021; AAI-8973-2021
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.
Is there a correlation between Gleason score and maximum standardized uptake value in locally advanced prostate cancer patients?
(2019) Cem, Onal; Torun, Nese; Guler, Ozan Cem; Reyhan, Mehmet; Yildirim, Berna Akkus; Yapar, Ali Fuat; 0000-0001-6908-3412; AAC-5654-2020
Kikuchi-Fujimoto Disease as A Rare Cause of Benign Lymphadenopathy and 18F-FDG PET/CT Findings
(2014) Erhamamci, Seval; Reyhan, Mehmet; Kocer, Nazim Emrah; https://orcid.org/0000-0001-8550-3368; https://orcid.org/0000-0002-5943-9283; 24563878; AAJ-5242-2021; AAM-5436-2021
Kikuchi-Fujimoto disease (KFD) is an uncommon benign and self-limited disease, characterized by cervical lymphadenopathy. This disease is generally diagnosed on the basis of an excisional biopsy of affected lymph nodes. However, clinical presentation and histopathological findings of KFD could lead to a wrong initial diagnosis, of tuberculosis, systemic lupus erythymatosus or malignant lymphoma. Laboratory tests are not specific. Imaging modalitites give confusing results. Affected lymph nodes of patients; with KFD can exibit F-18-FDG uptake on PET/CT imaging similar to malignant lymphoma. Therefore, the differential diagnosis of KFD should be considered in patients with cervical and/or generalized lymphadenopathy. Accurate diagnosis of KFD by histology is essential in avoiding unnecessary emotional and mental distress associated with the diagnosis of lymphoma.
Late pancreatic metastasis of renal cell carcinoma with absence of FDG-uptake in PET-CT
(2016) Karadeli, Elif; Tok, Sermin; Erbay, Gurcan; Reyhan, Mehmet; 0000-0002-1706-8680; 0000-0002-0352-8818; 0000-0001-8550-3368; AAK-5370-2021; AAK-5399-2021; AAJ-5242-2021
The primary tumors, which raise isolated pancreas metastases are frequently of renal origin, where colorectal cancer, melanoma, breast and lung cancers and sarcoma are the following causes of metastatic pancreas cancer. In this article, we present a case of pancreas-metastatic renal cell carcinoma with its radiological features, which did not exert anF-18 FDG-uptake in the whole-body positron emission tomography (PET).