Publications by authors named "Murat Tuncel"

41 Publications

Clinical parameters and nomograms for predicting lymph node metastasis detected with Ga-PSMA-PET/CT in prostate cancer patients candidate to definitive radiotherapy.

Prostate 2021 May 5. Epub 2021 May 5.

Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

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-naïve 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-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-PSMA-11 PET/CT for the detection of lymph node metastasis. Together with nomograms, Ga-PSMA-11 PET/CT images help to localize PSMA-positive lymph node metastases and can thus assist in surgery and radiotherapy planning.
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http://dx.doi.org/10.1002/pros.24142DOI Listing
May 2021

Can surgical adhesives may cause false positivity in follow-up positron emission tomography after lung cancer resection?

Tuberk Toraks 2021 Mar;69(1):59-64

Department of Nuclear Medicine, Hacettepe University School of Medicine, Ankara, Turkey.

Introduction: Postoperative complications following thoracic procedures are a major cause of morbidity and mortality. Alveolar air leaks and/or bronchopleural fistulas are associated with increased risk of infection, prolonged chest tube, and hospital stay duration and therefore generate economical concern for health care providers. A variety of surgical sealants or adhesives have been introduced to overcome this complication. Since intraoperative BioGlue® application can also cause an inflammatory reaction and mimic tumor recurrence on FDG PET-CT, in the present study we aimed to investigate its potential role in false-positive PET-CT results in patients operated for NSCLC.

Materials And Methods: Data of six patients who underwent resection for primary NSCLC at our institution (Department of Thoracic Surgery, Hacettepe University Medical Faculty) between January 2015 and December 2018 and had false positivity, due to BioGlue® application, at the bronchial stump in follow-up FDG PET-CT were retrospectively analyzed from a prospectively collected database.

Result: One of the 6 patients was female and 5 were male. The mean age was 68 years (range, 56-79 years). The average time interval between operation and postoperative FDG-PET imaging was 4.3 months (range, 4-6 months). Follow-up FDG-PET imaging SUVmax values ranged between 3.0 and 9.0 (median: 5.33). All patients have been evaluated by FDG-PET scan following the detection of soft tissue densities at the surgical site suspicious for recurrence at their follow-up chest CT scans. Four patients underwent a bronchoscopic examination, bronchial stumps were examined and multiple biopsies were taken from suspicious nodules or tissues and sent for pathologic examination. Histopathological results revealed inflammation which is compatible with foreign body granuloma, without any suspicion for malignancy, in all cases. Two patients were solely followed-up and subsequent FDG-PET imaging after 3 months revealed complete resolution of FDG uptake.

Conclusions: To avoid unnecessary biopsies or surgical procedures, the possibility of false-positive results due to surgical adhesive product use should be taken into account while interpreting follow-up FDG-PET imaging results and the operative reports should be written in detail, describing which surgical materials used and their exact application sites.
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http://dx.doi.org/10.5578/tt.20219907DOI Listing
March 2021

Predictive factors of tumor sink effect: Insights from Lu-Prostate-specific membrane antigen therapy.

Ann Nucl Med 2021 May 14;35(5):529-539. Epub 2021 Feb 14.

Faculty of Medicine, Department of Biostatistics, Hacettepe University, Sıhhiye, 06100, Ankara, Turkey.

Objective: Tumor sink effect (TSE) has been defined as; decreased uptake in healthy tissue with increased tumor sequestration of the radiopharmaceuticals. It enables us to give high tumoral radiation doses while resulting in lower absorbed radiation to critical organs. However, the factors which influence this effect are yet to be defined. In this study, we have investigated the predictive factors of the tumor sink effect in a group of patients who received Lu-Prostate-specific membrane antigen (PSMA) therapy due to progressive metastatic castration-resistant prostate cancer (mCRPC).

Methods: We have retrospectively analyzed the pre-therapy Ga-PSMA positron-emission tomography (PET)-computed tomography (CT) and post-therapy planar whole-body scans of 65 patients who received at least two cycles of 7.4 GBq of Lu-PSMA therapy. All patients with mCRPC were referred to our department after multiple treatment lines. Age, previous therapies, International Society of Urological Pathology (ISUP) score, and pre-therapy serum tumor marker levels were recorded. Post Lu-PSMA therapy images were analyzed for TSE. Ga-PSMA PET-CT images were used for the calculation of SUVmax in malignant and healthy tissues as well as metabolic tumor volume (MTV) and total lesion PSMA index (TLPI).

Results: Based on the post-therapy scans, TSE was seen in 17/65 (26.2%) patients. In univariate analysis, patients with TSE had higher pre-therapy PSA, PSA velocity, and ALP (p < 0.0001). In relation to PET parameters, patients with TSE had higher Ga-PSMA MTV, Ga-PSMA TLPI and lower pretherapy renal SUVmax (p < 0.0001)), pretherapy liver SUVmax (p:0.012), pretherapy parotid gland SUVmax (p:0.032), and pretherapy parotid gland SUVmean (p:0.038). In the multivariant analysis, Ga-PSMA TLPI, pre-therapy PSA, and PSA velocity were found to be statistically significant. When analyzed according to Youden index, pretherapy PSA level of 133 ng/ml (sensitivity 0.765 and 0.875), PSA velocity of 246 ng/ml/year (sensitivity 0.765 and 0.833), and Ga-PSMA TLPI of 2969 g (sensitivity 0.765 and 0.875) was found to be the best cut-off points to predict TSE.

Conclusion: The tumor sink effect was seen in 26.2% of patients. Ga- PSMA TLPI, pre-therapy PSA, and PSA velocity was found to be the predictors of TSE. Accurate prediction of TSE may lead to increased tumoral doses while sparing healthy organs. Clinical trials that consider this effect as a part of a dose algorithm may further increase therapeutic efficacy.
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http://dx.doi.org/10.1007/s12149-021-01593-9DOI Listing
May 2021

Colonic Visualization of 99mTc-DMSA Due to Enterovesical Fistula.

Clin Nucl Med 2021 Jan;46(1):66-68

From the Department of Nuclear Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

A 60-year-old woman with recurrent urinary tract infection who had several operations for colorectal carcinoma underwent Tc-DMSA renal scintigraphy which showed an unexpected accumulation of radiotracer in the colon. When symptoms were reviewed, we noticed that she was suffering from pneumaturia and fecaluria which raised the suspicion of enterovesical fistula. Rectal contrast-enhanced computer tomography of pelvis demonstrated enterovesical and enterovaginal fistulas. Colonic radioactivity was considered to be related to retrograde peristalsis of Tc-DMSA from bladder activity via enterovesical fistula. In patients with pelvic surgeries and radiotherapy, radioactivity in the colon should raise the suspicion of enterovesical fistula.
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http://dx.doi.org/10.1097/RLU.0000000000003386DOI Listing
January 2021

Diagnostic and therapeutic evaluation of folate-targeted paclitaxel and vinorelbine encapsulating theranostic liposomes for non-small cell lung cancer.

Eur J Pharm Sci 2021 Jan 25;156:105576. Epub 2020 Sep 25.

Department of Basic Oncology, Hacettepe University Cancer Institute, Ankara, Turkey.

NSCLC is the most common type of lung cancer. However, non-specific contrast agents, radiopharmaceuticals, and treatment methods are insufficient in early diagnosis and eradication of all tumor tissue. Therefore, the formulation of a novel, targeted, specific theranostic agents possess critical importance. In our previous study, paclitaxel and vinorelbine encapsulating, Tc-99m radiolabeled, folate targeted, nanosized liposomes were formulated and found promising due to characterization properties, high cellular uptake, and cytotoxicity. In this study, in vivo therapeutic and diagnostic efficacy of liposomal formulations were tested by biodistribution study, evaluation of tumor growth inhibition, and histopathologic examination after in vitro assays on LLC1 cells. Both actively and passively targeted liposomal formulations exhibited high cellular uptake, and co-drug encapsulating liposomes showed a greater cytotoxicity profiles than free drug combination in LLC1 cells. By the results of biodistribution studies performed in NSCLC tumor-bearing C57BL/6 mice, the uptake of radiolabeled, actively folate targeted, co-drug encapsulating liposomal formulation was found to be higher in tumor tissue when compared to non-actively targeted one. Also, more effective treatment was achieved by using folate-targeted, co-drug encapsulating liposomal formulation when compared to free drugs combination according to changes in tumor size of mice. Furthermore, liposomal formulations showed lower toxicity compared to free drug combinations in the toxicity study considering body weight. Moreover, according to the histopathological study, folate targeted, co-drug encapsulating liposomes not only inhibited the tumor growth effectively but also restricted the lung metastasis entirely.
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http://dx.doi.org/10.1016/j.ejps.2020.105576DOI Listing
January 2021

Bone scintigraphy as a gatekeeper for the detection of bone metastases in patients with prostate cancer: comparison with Ga-68 PSMA PET/CT.

Ann Nucl Med 2020 Dec 25;34(12):932-941. Epub 2020 Sep 25.

Department of Biostatistics, Medical Faculty, Hacettepe University, Ankara, Turkey.

Objectives: Gallium-68-labeled prostate-specific membrane antigen (Ga-PSMA) positron emission tomography (PET)/computed tomography (CT) is a valuable diagnostic tool for the detection of bone metastases in patients with prostate cancer (PCa). However, bone scintigraphy (BS) with technetium-labeled diphosphonates is cheap and widely available for the same patient population. PSMA PET comes with a cost, and financial constraints in the present economic environment may require its more selective use. In this study, we aimed to compare the diagnostic performance of BS with Ga-PSMA PET/CT for the detection of bone metastases in patients with PCa and correlate the results with various clinical and biochemical variables.

Materials And Methods: Ninety-five patients who underwent Ga-PSMA PET/CT and BS within 3 months for newly diagnosed or recurrent PCa were extracted from our database. Lesion, region and patient-based analyses were performed. Clinical and imaging follow-up was used as the reference test. Results were compared with tumor grade, serum prostate-specific antigen (PSA), and alkaline phosphatase (ALP) values.

Results: On the patient-based analysis, 75% (42/56) and 98.2% (55/56) of the patients with bone metastases were correctly diagnosed by BS and Ga-PSMA PET, respectively. In 26/95 patients with equivocal lesions on BS, Ga-PSMA PET correctly reclassified skeletal involvement in 11 and excluded metastases in 15 patients BS missed bone metastases in 3 patients. The true-positive rate of BS in patients with serum ALP ≥ 120U/L and PSA ≥ 50 ng/ml was 95.8% and 87.5 respectively.

Conclusion: Ga-PSMA is superior to BS for the evaluation of metastatic disease in patients with PCa. However, BS can also detect bone metastases in patients with PCa with a minimum sensitivity of 75%. Biochemical data are helpful to select patients with a high pretest probability who should undergo BS first as a part of the initial workup from an economic point of view. Due to its higher cost, Ga-PSMA PET should be performed in a selective group of patients when BS results are inconclusive or metastasis-directed therapy is planned.
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http://dx.doi.org/10.1007/s12149-020-01529-9DOI Listing
December 2020

Role of 68-Ga-PSMA-PET/CT in pelvic radiotherapy field definitions for lymph node coverage in prostate cancer patients.

Radiother Oncol 2020 10 28;151:222-227. Epub 2020 Aug 28.

Department of Radiation Oncology, Hacettepe University, Faculty of Medicine, Ankara, Turkey.

Purpose: To evaluate the distribution of metastatic lymph nodes (LN) detected on Ga-PSMA-positron emission tomography/computed tomography (PET/CT) in treatment-naïve prostate cancer (PC) patients and to analyze the LN coverage rates of the pelvic fields defined in the GETUG trial and RTOG guidelines and a pelvic field extending superiorly from the L4/L5 interspace.

Materials And Methods: Ga-PSMA-PET/CT images obtained at diagnosis of 138 PC patients were retrospectively analyzed. The number and locations of Ga-PSMA-positive LNs were co-registered with one single-planning CT. The numbers, locations, and sizes of LNs located outside the three pelvic volumes were investigated for the entire cohort and for patients with LN metastasis in the pelvic area only.

Results: A total of 441 PSMA-PET-positive LN metastases were identified. The most frequent metastatic LNs were internal iliac LNs (25.2%). Para-aortic and presacral LNs outside the three pelvic fields were present in 20 (14.5%) and 22 patients (15.9%), respectively. The LN coverage rates according to the GETUG trial, the RTOG guidelines, and the pelvic field extending superiorly from L4/L5 were 44.2%, 52.2%, and 71, respectively, in the entire cohort and 51.7%, 61 and 83.1%, respectively, in patients with only pelvic LN metastasis. The number of metastatic LNs was a predictive factor for LNs located outside the three pelvic fields.

Conclusions: Extending the cranial margin of the pelvic field from L5/S1 to L4/L5 increases the accuracy of pelvic field irradiation in approximately 20% of patients, highlighting the importance of proximal common iliac irradiation, particularly in patients with multiple LN metastasis.
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http://dx.doi.org/10.1016/j.radonc.2020.08.021DOI Listing
October 2020

The role of Tc-99m MIBI scintigraphy in clinical T1 renal mass assessment: Does it have a real benefit?

Urol Oncol 2020 12 26;38(12):937.e11-937.e17. Epub 2020 Aug 26.

Department of Urology, Hacettepe University School of Medicine, Ankara, Turkey.

Introduction: Despite the increasing accuracy of imaging modalities, the rate of benign renal tumors misclassified as malignant before surgery still non-negligible. Tc-99m sestamibi was demonstrated to be a possible reliable agent in discriminating oncocytoma from renal cell carcinoma (RCC). We aimed to study the efficacy of Tc-99m MIBI tumor scintigraphy in evaluating clinical T1 renal masses.

Methods And Materials: Between July 2017 and March 2019, patients with clinical T1 renal mass underwent preoperative Tc-99m sestamibi tumor scintigraphy. Tc-99m sestamibi tumor scintigraphy findings were correlated with the postoperative pathology results.

Results: A total of 90 renal masses were included in the study. Male to female ratio was 67/23. The mean age and tumor size were 55.5 ± 11.4 years and 4 ± 1.4 cm, respectively. In pathological evaluation, 20% (18/90) of masses were reported as benign (10 oncocytomas, 4 angiomyolipomas (AML), 2 chronic sclerosis, 1 fibroma and 1 hydatid cyst). While Tc-99m sestamibi uptake was positive in all oncocytomas; 6 patients with chronic sclerosis, fibroma, hydatid cyst and angiomyolipoma pathologies had no uptake. Except for 5 chromophobe cell RCC and 3 oncocytic papillary RCC masses, malignant lesions had no uptake. In predicting benign pathology, Tc-99m sestamibi tumor scintigraphy had positive and negative predictive value of 60% and 91.3%, respectively. The mean Tc-99m 2-methoxy isobutyl isonitrile lesion/normal renal parenchyma ratio of benign and malignant lesions was 0.6 and 0.37, respectively. A relative uptake of 0.49 was an acceptable cutoff point to discriminate oncocytomas from all other pathologies.

Conclusion: Tc-99m sestamibi tumor scintigraphy has a beneficial role in the assessment of clinical T1 renal mass. Masses with negative uptake harbor high probability of being malignant. While evaluating masses with positive uptake, it should be kept in mind that some malignant pathologies may demonstrate similar results.
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http://dx.doi.org/10.1016/j.urolonc.2020.07.018DOI Listing
December 2020

Clinical Impact of PET Imaging in Patients With Metastatic Prostate Cancer.

Clin Nucl Med 2020 Oct;45(10):757-764

Medical Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

Prostate cancer (Pca) is the most common cancer and the second leading cause of death among men. Although conventional bone scans and abdominal CT are preferred in most of the guidelines and clinical trials, PET/CT has already started to become the inevitable part of Pca management because of its higher sensitivity and specificity. Radiotracers used for PET imaging show different molecular aspects of the disease process. Although Ga-prostate-specific membrane antigen offers the highest sensitivity and specificity, other PET radiotracers such as F-FDG and Ga-DOTATATE still have a role in patients with prostate-specific membrane antigen-negative diseases such as Pca with neuroendocrine differentiation. In this pictorial essay, we have presented a series of patients with metastatic Pca who had PET images with different radiotracers and discussed the clinical role of this imaging modality in patient management.
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http://dx.doi.org/10.1097/RLU.0000000000003126DOI Listing
October 2020

Clinical impact of Ga-DOTATATE PET-CT imaging in patients with medullary thyroid cancer.

Ann Nucl Med 2020 Sep 29;34(9):663-674. Epub 2020 Jun 29.

Department of Head and Neck Surgery, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

Purpose: Medullary thyroid cancer (MTC) arises from neuroendocrine C cells of the thyroid. There is no single diagnostic imaging method that can reveal all MTC recurrences or metastases. Ga-DOTATATE is an alternative PET radiotracer that showed acceptable efficacy in the detection of MTC. In this study, we aimed to reveal the clinical efficacy and impact of this radiotracer on the management of patients with MTC.

Methods: The Ga-DOTATATE PET-CT records of 38 patients with confirmed MTC were included in the study. The demographic data, clinical indication for the scan, previous therapies, and tumor marker levels were recorded. The site and SUVmax of the lesions were also noted. A consensus was reached on the additional value of Ga-DOTATATE PET-CT, and sites with discordant results on conventional imaging (CI). Finally, changes in management after the scan were evaluated.

Results: Ga-DOTATATE PET-CT outperformed CI in 14/38 (37%) patients. In these 14 patients, metastatic lymph nodes were detected in 8, bone metastases in 4, and both bone and lymph nodes metastases in 2 patients. In 16/38 (42%) patients, Ga-DOTATATE PET-CT performed equally well as CI. In 5/38 (13%) patients, CI outperformed PET-CT. Most of the patients (4/5) in this group had hepatic metastases. Ga-DOTATATE PET-CT positivity was also correlated with tumor marker expression [median calcitonin; PET-positive: 743 ± 5439 vs PET-negative: 45 ± 17 (p:0.012), median CEA; PET-positive: 41 ± 162 vs PET-negative: 2.6 ± 1.4 (p:0.015)]. Ga-DOTATATE PET-CT changed the clinical management of 13/38 (34%) patients. The information provided by PET-CT resulted in neck surgery in 5/13 patients, external radiotherapy in 3/13 and both in one patient. Four of these thirteen patients were found to be eligible for peptide receptor radionuclide therapy.

Conclusion:  Ga-DOTATATE is an essential part of the work-up for patients with MTC. This modality outperformed CI in 14/38 (37%) patients and changed the clinical management in 13/38 (34%) patients. Prospective randomized studies with image-guided therapy decisions are needed to further reveal the impact of PET imaging in patients with MTC.
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http://dx.doi.org/10.1007/s12149-020-01494-3DOI Listing
September 2020

Using a pessary during radiotherapy in reducible pelvic organ prolapse and vaginal cancer: a case report and review of the literature.

J Contemp Brachytherapy 2020 Apr 11;12(2):175-180. Epub 2020 Feb 11.

Department of Radiation Oncology, Hacettepe University Medical School, Ankara, Turkey.

Purpose: Primary vaginal cancer and pelvic organ prolapse (POP) combination is extremely rare. Although definitive chemoradiotherapy (CRT) and brachytherapy (BT) is the standard treatment for advanced stage primary vaginal cancer, there is a limited data about the treatment of primary vaginal cancer combined with POP due to its rarity. In addition, radiotherapy (RT) process may be difficult in these cases and often result in more toxicity.

Case Presentation: In this case report, we present a 77-year-old woman with a diagnosis of primary vaginal cancer associated with POP, who was treated with definitive CRT using a pessary to restore vaginal anatomy for optimal radiation. Following CRT, complete response was observed and vaginal cuff BT was performed. The patient tolerated the treatment very well and is still alive without disease at 10-months follow-up.

Conclusions: Combined primary vaginal cancer and POP is an extremely rare clinical entity, with only a few cases reported in the literature. When applying CRT in these cases, critical organ doses may be higher than expected due to the downward descent of the pelvic organs. Especially in elderly patients, a pessary can be used as a non-surgical procedure to restore the anatomy for symptom relief during definitive CRT. Additionally, it allows tumors to be targeted more precisely.
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http://dx.doi.org/10.5114/jcb.2020.92997DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7207234PMC
April 2020

Stereotactic ablative radiotherapy for bone metastasis of gastrointestinal stromal tumor: Case report and review of the literature.

Rep Pract Oncol Radiother 2020 May-Jun;25(3):331-335. Epub 2020 Feb 24.

Hacettepe University Faculty of Medicine, Department of Radiation Oncology, Ankara, Turkey.

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. These tumors are rare and only make bone metastases at a rate of 5%.

Case Summary: A 31-year-old male with a GIST presented with solitary bone metastasis at the right iliac bone. We performed stereotactic ablative radiotherapy (SABR) and achieved excellent local control. Herein, our case is presented, and a short review of the literature is carried out.

Conclusion: SABR should be considered as a treatment option in GIST with bone metastasis.
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http://dx.doi.org/10.1016/j.rpor.2020.02.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7114605PMC
February 2020

Comparison of clinical and PET-derived prognostic factors in patients with non-Hodgkin lymphoma: a special emphasis on bone marrow involvement.

Nucl Med Commun 2020 Jun;41(6):540-549

Nuclear Medicine, Hacettepe University-Cancer Institute, Ankara.

Objective: In patients with non-Hodgkin lymphoma (NHL), we investigated F FDG PET/computed tomography (CT) parameters, clinical findings, laboratory parameters, and bone marrow involvement (BMI) status for predictive methods in progression-free survival (PFS) and overall survival (OS), and whether F FDG PET/CT could take the place of bone marrow biopsy (BMB).

Methods: The performance of F FDG PET/CT (BMPET) was evaluated. The prognostic value of maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), stage, international prognostic index (IPI) score, IPI risk, lactate dehydrogenase (LDH), B2 microglobulin, Ki67 proliferation index, and the presence of BMI was evaluated for OS and PFS. Kaplan-Meier curves were drawn for each designated cutoff value, and 5-year PFS and 7-year OS were evaluated using log-rank analysis.

Results: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of BMPET and BMB to identify BMI were 69, 100, 86.1, 80, 100%, and 81.6, 100, 92.5, 89, 100%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of BMPET in patients with Ki67- proliferation index >25% were all 100%. BMPET, IPI risk, MTV, and LDH were found to be independent prognostic predictors for PFS, whereas BMPET, SUVmax, and MTV for OS. Five-year PFS analysis estimated as follows: BMPET (+) = 22%, BMPET (-) = 80%, LDH ≤ 437 (U/L) = 86%, LDH > 437 (U/L) = 51%, MTV ≤ 56 (cm) = 87%, MTV > 56 (cm) = 49%, low IPI risk = 87%, intermediate IPI risk = 69%, high IPI risk = 25%. Seven-year OS analysis was found as: SUVmax ≤ 17.6 = 80%, SUVmax > 17.6 = 48%, MTV ≤ 56 (cm) = 84.4%, MTV > 56 (cm) = 45.8%, BMPET (-) = 72.5%, BMPET (+) = 42%.

Conclusion: In the Ki-67 proliferation index > 25% group, F FDG PET/CT was able to differentiate BMI independently from NHL subgroups. We recommend using this method with large patient groups. MTV and BMPET were independent prognostic indicators for OS and PFS and may help to determine high-risk patients.
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http://dx.doi.org/10.1097/MNM.0000000000001182DOI Listing
June 2020

Thyroid volumes and serum VEGF levels in dyslipidemic patients: effects of statin treatment

Turk J Med Sci 2019 06 18;49(3):738-745. Epub 2019 Jun 18.

Department of Endocrinology and Metabolism, Faculty of Medicine, Hacettepe University, Ankara, Turkey

Background/aim: Defective vascularization may be important in thyroid nodular disease. In this study, we aimed to investigate serum vascular endothelial growth factor (VEGF) levels in dyslipidemic patients with thyroid nodules, as well as the effects of statin therapy

Materials And Methods: The study included 37 dyslipidemic patients with thyroid nodules and 32 dyslipidemic patients without thyroid nodules. Anthropometry, serum VEGF levels, biochemical parameters, thyroid-stimulating hormone (TSH), free triiodothyronine (fT3) and free thyroxine (fT4) levels, and thyroid sonography were determined before and after 6 months of statin therapy.

Results: Patients with and without thyroid nodules had similar metabolic parameters. Serum VEGF levels did not differ between the groups. In patients with nodules, VEGF levels remained unchanged (P = 0.931) after statin therapy. However, serum VEGF levels were lowered by statin treatment in patients without nodules (P = 0.030). Statin therapy resulted in a decrease in the dominant thyroid nodule volume. The changes in thyroid volume and dominant thyroid nodule volume were not correlated with changes in VEGF, body mass index, total cholesterol, low-density lipoprotein cholesterol, or homeostatic model assessment of insulin resistance (HOMA-IR).

Conclusion: Although statin treatment decreases serum VEGF levels in dyslipidemic patients without thyroid nodules, it has no lowering effect on serum VEGF levels in patients with thyroid nodules. The decrease in thyroid nodule volume with statin treatment was associated with neither metabolic parameters nor serum VEGF levels.
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http://dx.doi.org/10.3906/sag-1708-106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7018346PMC
June 2019

Radioguided occult lesion localization in patients with recurrent thyroid cancer.

Eur Arch Otorhinolaryngol 2019 Jun 18;276(6):1757-1766. Epub 2019 Mar 18.

Head and Neck Surgery, Hacettepe University, Faculty of Medicine, Ankara, Turkey.

Purpose: Well planned re-surgery is critical for recurrent/persistent thyroid cancer (TC). We aimed to investigate the clinical outcome of radioguided-occult lesion localization (ROLL) guided surgery in patients with recurrent/persistent TC.

Methods: This study includes 29 patients [F/M: 22/7, median age 43 ± 12 years (18-58)] with a diagnosis of TC (22 papillary, 2 follicular and 5 medullary). Before surgery, all patients underwent ultrasonography (USG) guided mapping and intra-lesional radioactivity injection. Surgery was performed based on the excision of radioactivity injected lesions by a gamma probe and non-injected tumor foci via USG-neck map. Researchers determined surgical success by post-operative tumor markers and neck-USG.

Results: Among 29 patients, 60 metastatic lesions were identified by USG [median size 10 ± 6.3 mm (range 5-30)]. Neck-USG performed after surgery provided no evidence of disease (NED) in %97 (28/29) of TC patients. In the follow-up, stimulated thyroglobulin (Tg) levels were less than 1 ng/ml in 79%(19/24) of DTC patients and suppressed Tg < 0.2 ng/ml was noted in 92% (22/24).In patients with DTC with an incomplete structural response, we dramatically changed the American Thyroid Association (ATA) response category and achieved an excellent response in 92% (22/24) of patients. Among patients with MTC, 5/5 patients had normal USG and calcitonin levels were reduced by 60-80% in 4/5 and > 80% in1/5 patients.

Conclusions: In this study we have shown that, ROLL-guided surgery yielded NED rate of %97 (28/29) and increased excellent response rates according to ATA guidelines. Further studies with larger patient groups and longer follow-up should be performed to confirm the efficacy of this surgery.
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http://dx.doi.org/10.1007/s00405-019-05377-wDOI Listing
June 2019

Ga-labelled PSMA ligand HBED-CC PET/CT imaging in patients with recurrent prostate cancer.

World J Urol 2019 May 27;37(5):813-821. Epub 2018 Aug 27.

Department of Nuclear Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

Background: Ga-PSMA Positron Emission Tomography/Computerized Tomography (PET/CT) has shown promising results for the detection of recurrent prostate cancer (RPCa). However, the diagnostic value of this method is yet to be validated. The aim of this study was to determine the influence of clinical and biochemical variables on the detection rate of Ga-PSMA PET/CT in patients with RPCa.

Methods: This is a prospective study of 121 patients who underwent Ga-PSMA-PET/CT and conventional imaging (CI) for RPCa. Detection rates were analyzed and correlated with various clinical and biochemical variables such as Gleason score GS), androgen deprivation therapy (ADT), trigger PSA (tPSA), PSA doubling-time (PSAdt) and PSA velocity (PSAv).

Results: Ga-PSMA-PET/CT showed at least one focus of pathological Ga-PSMA uptake in 92/121 (76%) of patients. Nodal metastases (in 47% of patients) were the most common site of recurrent disease followed by bones (36%) and prostate (32%). Out of 121 patients, 57 (47%) had only positive findings on PSMA scan verified by biopsy or follow-up. The majority of these lesion were located in the lymph nodes (31/57, 54,5%), which were below the detection limit of CT. Univariate analysis showed higher detection rate of PET/CT with increasing tPSA, PSAv and short PSAdt. Best cutoff for tPSA, PSAv and PSAdt was 0.5 ng/ml, 2.25 ng/ml/year and 8.65 months, respectively. The detection rate of PSMA-PET/CT was higher in patients with high grade tumors (GS > 7, 23.7% vs 76.3%) and in patients who were on ADT during of PSMA scan (76.3% vs 96%). In multiple logistic regression analysis, PSAdt and concurrent ADT were identified as predictors of positive Ga-PSMA-PET/CT.

Conclusion: Ga-PSMA-PET/CT is useful for re-staging patients with RPCa and has improved performance compared with CI for disease detection. Detection rates are improved in patients on ADT and with short PSAdt.
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http://dx.doi.org/10.1007/s00345-018-2460-yDOI Listing
May 2019

Thyroid Stimulating Hormone Receptor.

Authors:
Murat Tuncel

Mol Imaging Radionucl Ther 2017 02;26(Suppl 1):87-91

Hacettepe University Faculty of Medicine, Department of Nuclear Medicine, Ankara, Turkey, Phone: +90 536 213 03 41, E-mail:

Thyroid stimulating hormone receptor (TSHR) plays a pivotal role in thyroid hormone metabolism. It is a major controller of thyroid cell function and growth. Mutations in TSHR may lead to several thyroid diseases, most commonly hyperthyroidism. Although its genetic and epigenetic alterations do not directly lead to carcinogenesis, it has a crucial role in tumor growth, which is initiated by several oncogenes. This article will provide a brief review of TSHR and related diseases.
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http://dx.doi.org/10.4274/2017.26.suppl.10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5283706PMC
February 2017

Comparison of wire-guided localization and radio-guided occult lesionlocalization in preoperative localization of nonpalpable breast lesions.

Turk J Med Sci 2016 Dec 20;46(6):1829-1837. Epub 2016 Dec 20.

Department of Nuclear Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey.

Background/aim: Breast lesions that are not palpable on physical examination but considered suspicious for malignancy on mammography or ultrasonography should be marked before surgery. Wire-guided localization (WGL) is the most frequently used method for preoperative marking of nonpalpable breast lesions (NPBLs). An alternative is marking by a radioactive agent (radio-guided occult lesion localization; ROLL). The present study aimed to compare WGL and ROLL for preoperative marking.

Materials And Methods: The study included 25 patients marked by ROLL and 11 patients marked by WGL. The groups were compared in terms of patient and lesion characteristics, method-related characteristics, hospital stay duration, complications, cosmetic outcomes, and rate of correct marking.

Results: Suspicious lesions were marked with a success rate of 95.6% by ROLL and 100% by WGL. Complications and pain sensation rates were found significantly lower in the ROLL group compared to WGL. Although ROLL was considered more advantageous in terms of hospital stay duration, positive surgical margins, cosmetic outcomes, and excision duration, the differences between the groups were not statistically significant.

Conclusion: ROLL, which is a simple, comfortable, and reliable method, could be used as an alternative to the WGL in preoperative marking of NPBLs.
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http://dx.doi.org/10.3906/sag-1507-162DOI Listing
December 2016

Prognosis estimation under the light of metabolic tumor parameters on initial FDG-PET/CT in patients with primary extranodal lymphoma.

Radiol Oncol 2016 Dec 8;50(4):360-369. Epub 2016 Sep 8.

Department of Nuclear Medicine, Gulhane Military Medical Academy (GATA), Ankara, Turkey.

Background: Non-Hodgkin's lymphomas arising from the tissues other than primary lymphatic organs are named primary extranodal lymphoma. Most of the studies evaluated metabolic tumor parameters in different organs and histopathologic variants of this disease generally for treatment response. We aimed to evaluate the prognostic value of metabolic tumor parameters derived from initial FDG-PET/CT in patients with a medley of primary extranodal lymphoma in this study.

Patients And Methods: There were 67 patients with primary extranodal lymphoma for whom FDG-PET/CT was requested for primary staging. Quantitative PET/CT parameters: maximum standardized uptake value (SUVmax), average standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to estimate disease-free survival and overall survival.

Results: SUVmean, MTV and TLG were found statistically significant after multivariate analysis. SUVmean remained significant after ROC curve analysis. Sensitivity and specificity were calculated as 88% and 64%, respectively, when the cut-off value of SUVmean was chosen as 5.15. After the investigation of primary presentation sites and histo-pathological variants according to recurrence, there is no difference amongst the variants. Primary site of extranodal lymphomas however, is statistically important (p = 0.014). Testis and central nervous system lymphomas have higher recurrence rate (62.5%, 73%, respectively).

Conclusions: High SUVmean, MTV and TLG values obtained from primary staging FDG-PET/CT are potential risk factors for both disease-free survival and overall survival in primary extranodal lymphoma. SUVmean is the most significant one amongst them for estimating recurrence/metastasis.
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http://dx.doi.org/10.1515/raon-2016-0045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5120580PMC
December 2016

Clinical impact of SPECT-CT on bone scintigraphy in oncology: Pattern approach.

J BUON 2016 Sept-Oct;21(5):1296-1306

Department of Nuclear Medicine, Hacettepe University, Faculty of Medicine, Ankara, Turkey.

Purpose: The recent addition of single photon emission computed tomography (SPECT)-CT into bone scintigraphy (BS), increased the accuracy of the test. The objective of this study was to define the main problematic scintigraphic patterns that were solved with the contribution of SPECT-CT and serve as a guide to the medical oncologist who will refer their patients to BS.

Methods: Two hundred and ten patients (median age 62 years, range 12-80, F/M:122/ 88) with diagnosis of cancer (breast 109;52%, prostate 63;30%, lung 15;7% and others 20;11%) were referred for BS. Subsequent SPECT-CT images (231 images from 210 patients) were obtained from the related body regions where suspicious skeletal radioactivity uptake had been observed. BS and SPECT-CT images were classified into groups according to the BS, clinical history and other imaging results in consideration with the role of SPECT-CT for more accurate diagnosis.

Results: SPECT-CT studies resulted in the emergence of 6 main patterns that helped improve the interpretation of the whole-body BS for more accurate diagnosis. Pattern 1: Extraskeletal uptake and/or incidental findings (14/231;6%); Pattern 2: Identification of skeletal trauma and degenerative osteoarthritic diseases (147/231;64%); Pattern 3: Benign bone tumors and reactions (12/231;5%); Pattern 4: Sclerotic-mixed type metastases (32;14%); Pattern 5: Lytic/ bone marrow metastases (12/231;5%); Pattern 6: Metabolically inactive metastases (14/231;6%).

Conclusion: SPECT-CT is a revolutionary technique that improved the interpretation of BS. Recognition of patterns of disease that may be resolved with SPECT-CT will help significantly to better understanding the patient's bone disease.
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June 2017

Renal Function Assessment During Peptide Receptor Radionuclide Therapy.

Semin Nucl Med 2016 09;46(5):462-78

Department of Nuclear Medicine, Hacettepe University, Medical School, Ankara, Turkey.

Theranostics labeled with Y-90 or Lu-177 are highly efficient therapeutic approaches for the systemic treatment of various cancers including neuroendocrine tumors and prostate cancer. Peptide receptor radionuclide therapy (PRRT) has been used for many years for metastatic or inoperable neuroendocrine tumors. However, renal and hematopoietic toxicities are the major limitations for this therapeutic approach. Kidneys have been considered as the "critical organ" because of the predominant glomerular filtration, tubular reabsorption by the proximal tubules, and interstitial retention of the tracers. Severe nephrotoxity, which has been classified as grade 4-5 based on the "Common Terminology Criteria on Adverse Events," was reported in the range from 0%-14%. There are several risk factors for renal toxicity; patient-related risk factors include older age, preexisting renal disease, hypertension, diabetes mellitus, previous nephrotoxic chemotherapy, metastatic lesions close to renal parenchyma, and single kidney. There are also treatment-related issues, such as choice of radionuclide, cumulative radiation dose to kidneys, renal radiation dose per cycle, activity administered, number of cycles, and time interval between cycles. In the literature, nephrotoxicity caused by PRRT was documented using different criteria and renal function tests, from serum creatinine level to more accurate and sophisticated methods. Generally, serum creatinine level was used as a measure of kidney function. Glomerular filtration rate (GFR) estimation based on serum creatinine was preferred by several authors. Most commonly used formulas for estimation of GFR are "Modifications of Diet in Renal Disease" (MDRD) equation and "Cockcroft-Gault" formulas. However, more precise methods than creatinine or creatinine clearance are recommended to assess renal function, such as GFR measurements using Tc-99m-diethylenetriaminepentaacetic acid (DTPA), Cr-51-ethylenediaminetetraacetic acid (EDTA), or measurement of Tc-99m-MAG3 clearance, particularly in patients with preexisting risk factors for long-term nephrotoxicity. Proximal tubular reabsorption and interstitial retention of tracers result in excessive renal irradiation. Coinfusion of positively charged amino acids, such as l-lysine and l-arginine, is recommended to decrease the renal retention of the tracers by inhibiting the proximal tubular reabsorption. Furthermore, nephrotoxicity may be reduced by dose fractionation. Patient-specific dosimetric studies showed that renal biological effective dose of <0Gy was safe for patients without any risk factors. A renal threshold value <28Gy was recommended for patients with risk factors. Despite kidney protection, renal function impairment can occur after PRRT, especially in patients with risk factors and high single or cumulative renal absorbed dose. Therefore, patient-specific dosimetry may be helpful in minimizing the renal absorbed dose while maximizing the tumor dose. In addition, close and accurate renal function monitoring using more precise methods, rather than plasma creatinine levels, is essential to diagnose the early renal functional changes and to follow-up the renal function during the treatment.
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http://dx.doi.org/10.1053/j.semnuclmed.2016.04.006DOI Listing
September 2016

Nuclear Medicine in Pediatric and Adolescent Tumors.

Semin Nucl Med 2016 07;46(4):308-23

Department of Nuclear Medicine, Schneider Children's Medical Center, Petah Tikva, Israel.

Nuclear medicine has an important role in the management of many cancers in pediatric age group with multiple imaging modalities and radiopharmaceuticals targeting various biological uptake mechanisms. 18-Flourodeoxyglucose is the radiotracer of choice especially in patients with sarcoma and lymphoma. (18)FDG-PET, for sarcoma and lymphomas, is proved to be superior to conventional imaging in staging and therapy response. Although studies are limited in pediatric population, (18)FDG-PET/CT has found its way through international guidelines. Limitations and strengths of PET imaging must be noticed before adapting PET imaging in clinical protocols. Established new response criteria using multiple parameters derived from (18)FDG-PET would increase the accuracy and repeatability of response evaluation. Current data suggest that I-123 metaiodobenzylguanidine (MIBG) remains the tracer of choice in the evaluation of neuroblastoma (NB) because of its high sensitivity, specificity, diagnostic accuracy, and prognostic value. It is valuable in determining the response to therapy, surveillance for disease recurrence, and in selecting patients for I-131 therapy. SPECT/CT improves the diagnostic accuracy and the interpretation confidence of MIBG scans. (18)FDG-PET/CT is an important complementary to MIBG imaging despite its lack of specificity to NB. It is valuable in cases of negative or inconclusive MIBG scans and when MIBG findings underestimate the disease status as determined from clinical and radiological findings. F-18 DOPA is promising tracer that reflects catecholamine metabolism and is both sensitive and specific. F-18 DOPA scintigraphy provides the advantages of PET/CT imaging with early and short imaging times, high spatial resolution, inherent morphologic correlation with CT, and quantitation. Regulatory and production issues currently limit the tracer's availability. PET/CT with Ga-68 DOTA appears to be useful in NB imaging and may have a unique role in selecting patients for peptide receptor radionuclide therapy with somatostatin analogues. C-11 hydroxyephedrine PET/CT is a specific PET tracer for NB, but the C-11 label that requires an on-site cyclotron production and the high physiologic uptake in the liver and kidneys limit its use. I-124 MIBG is useful for I-131 MIBG pretherapeutic dosimetry planning. Its use for diagnostic imaging as well as the use of F-18 labeled MIBG analogues is currently experimental. PET/MR imaging is emerging and is likely to become an important tool in the evaluation. It provides metabolic and superior morphological data in one imaging session, expediting the diagnosis and lowering the radiation exposure. Radioactive iodines not only detect residual tissue and metastatic disease but also are used in the treatment of differentiated thyroid cancer. However, these are not well documented in pediatric age group like adult patients. Use of radioactivity in pediatric population is very important and strictly controlled because of the possibility of secondary malignities; therefore, management of oncological cases requires detailed literature knowledge. This article aims to review the literature on the use of radionuclide imaging and therapy in pediatric population with thyroid cancer, sarcomas, lymphoma, and NB.
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http://dx.doi.org/10.1053/j.semnuclmed.2016.01.004DOI Listing
July 2016

Nanosized multifunctional liposomes for tumor diagnosis and molecular imaging by SPECT/CT.

J Liposome Res 2013 Mar 19;23(1):20-7. Epub 2012 Oct 19.

Department of Radiopharmacy, Faculty of Pharmacy, Hacettepe University, 06100, Ankara, Turkey.

Among currently used cancer imaging methods, nuclear medicine modalities provide metabolic information, whereas modalities in radiology provide anatomical information. However, different modalities, having different acquisition times in separate machines, decrease the specificity and accuracy of images. To solve this problem, hybrid imaging modalities were developed as a new era, especially in the cancer imaging field. With widespread usage of hybrid imaging modalities, specific contrast agents are essentially needed to use in both modalities, such as single-photon emission computed tomography/computed tomography (SPECT/CT). Liposomes are one of the most desirable drug delivery systems, depending on their suitable properties. The aim of this study was to develop a liposomal contrast agent for the diagnosis and molecular imaging of tumor by SPECT/CT. Liposomes were prepared nanosized, coated with polyethylene glycol to obtain long blood circulation, and modified with monoclonal antibody 2C5 for specific tumor targeting. Although DTPA-PE and DTPA-PLL-NGPE (polychelating amphilic polymers; PAPs) were loaded onto liposomes for stable radiolabeling for SPECT imaging, iopromide was encapsulated into liposomes for CT imaging. Liposomes [(DPPC:PEG(2000)-PE:Chol:DTPA-PE), (PL 90G:PEG(2000)-PE:Chol:DTPA-PE), (DPPC:PEG(2000)-PE:Chol:PAPs), (PL 90G:PEG(2000)-PE:Chol:PAPs), (60:0.9:39:0.1% mol ratio)] were characterized in terms of entrapment efficiency, particle size, physical stability, and release kinetics. Additionally, in vitro cell-binding studies were carried out on two tumor cell lines (MCF-7 and EL 4) by counting radioactivity. Tumor-specific antibody-modified liposomes were found to be effective multimodal contrast agents by designating almost 3-8 fold more uptake than nonmodified ones in different tumor cell lines. These results could be considered as an important step in the development of tumor-targeted SPECT/CT contrast agents for cancer imaging.
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http://dx.doi.org/10.3109/08982104.2012.722107DOI Listing
March 2013

Gastroesophageal reflux scintigraphy: interpretation methods and inter-reader agreement.

World J Pediatr 2011 Aug 7;7(3):245-9. Epub 2011 Aug 7.

Department of Nuclear Medicine, Hacettepe University Faculty of Medicine, Sihhiye, Ankara, 06110, Turkey.

Background: Scintigraphic imaging is a useful screening tool for patients with suspected gastroesophageal reflux. New scintigraphic interpretation methods have recently been introduced. This study was undertaken to evaluate the efficiency of various scintigraphic interpretation methods in the detection of gastroesophageal reflux and to measure their influence on inter-reader agreement.

Methods: Scintigraphic images of 49 children with suspected gastroesophageal reflux were interpreted by three different methods: visual interpretation, time activity curves, and condensed images. The readings were performed by three specialists and a resident. The discordant results were resolved by a consensus reading done together by all interpreters based on the three different methods. The gastroesophageal refluxes were grouped according to their number, location and intensity.

Results: Gastroesophageal reflux scintigraphy revealed 22 patients with negative results and 27 with positive results. The sensitivity, positive predictive value and specificity for each of the three specialists vs. the resident were 96%, 96% and 81% vs. 96%; 93%, 90% and 96% vs. 81%; and 90%, 86%, and 95% vs. 73%, respectively. The mean inter-observer reproducibility (κ value) was 0.910 for visual interpretation, 0.652 for time activity curves and 0.789 for condensed images. Twenty-seven percent of the results were discordant and most of these refluxes were of low grade (92%), low intensity (77%) and localization in the distal esophagus (54%).

Conclusion: Gastroesophageal scintigraphy is a useful tool for detecting patients with suspected reflux, and visual interpretation is better than the other two methods in terms of accuracy and inter-observer reproducibility.
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http://dx.doi.org/10.1007/s12519-011-0322-4DOI Listing
August 2011

Evaluation of outcome prediction and disease extension by quantitative 2-deoxy-2-[18F] fluoro-D-glucose with positron emission tomography in patients with small cell lung cancer.

Ann Nucl Med 2011 Jul 17;25(6):406-13. Epub 2011 Mar 17.

Department of Nuclear Medicine, Gülhane Military Medical Academy and Medical Faculty, Ankara, Turkey.

Objective: The objective of this study is to determine whether 2-deoxy-2-[18F] fluoro-D: -glucose with positron emission tomography (FDG-PET) imaging and quantitative PET parameters can predict outcome and differentiate patients with limited disease (LD) from extensive disease (ED) in patients with small cell lung cancer (SCLC).

Methods: We retrospectively evaluated data from 25 patients who underwent either initial staging (Group A, n 12) or restaging (Group B, n 13) by conventional imaging methods and FDG-PET according to the simplified staging scheme developed by the Veterans Administration Lung Cancer Study Group-2. FDG-PET images were both visually and quantitatively evaluated with SUV(max), SUV(ave), total metabolic tumor volume (with SUV(max) > %50 and SUV(max) > 2.5), total lesion glycolysis (TLG) (with SUV(max) > %50 and SUV(max) > 2.5). The correlation between quantitative PET parameters, disease stages and survival were analyzed.

Results: By conventional methods 14 of 25 (56%) patients were reported to have LD and 11 of 25 (44%) had ED. FDG-PET scan upstaged 9 out of 25 (36%) and downstaged 2 out of 25 (%8) patients. Among the quantitative PET parameters, TLGs were the only PET parameters that differentiated between Group A and Group B patients. FDG-PET staging (p = 0.019) could predict significant survival difference between stages on contrary to conventional staging (p = 0.055). Moreover, TLG [SUV(max) > %50] was the only quantitative PET parameter that could predict survival (p = 0.027).

Conclusion: FDG-PET imaging is a valuable tool in the management of patients with SCLC for a more accurate staging. The use of quantitative PET parameters may have a role in prediction of stage and survival.
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http://dx.doi.org/10.1007/s12149-011-0478-yDOI Listing
July 2011

Butterfly vertebra: a diagnostic pitfall on bone scintigraphy.

Clin Nucl Med 2010 Apr;35(4):293-4

Department of Nuclear Medicine, Hacettepe University, Ankara, Turkey.

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http://dx.doi.org/10.1097/RLU.0b013e3181d18fdfDOI Listing
April 2010

Gated myocardial perfusion scintigraphy in children with myocarditis: can it be considered as an indicator of clinical outcome?

Nucl Med Commun 2008 Oct;29(10):907-14

Department of Nuclear Medicine, Division of Cardiology, Hacettepe University, Ankara, Turkey.

Purpose: Myocarditis is an inflammation of the heart muscle and represents a challenge for diagnosis and treatment. On account of the lack of sensitivity and specificity of routine cardiac tests, there is a need for accurate diagnostic imaging. The aim of this study is to review the role of gated 99Tc-methoxyisobutylisonitrile myocardial perfusion scintigraphy (G-MPS) in the diagnosis and follow-up of the patients with myocarditis in comparison with gallium scintigraphy.

Materials And Methods: Thirteen patients with a clinical diagnosis of myocarditis were included in the study. All underwent rest G-MPS and the images were then evaluated by quantitative perfusion single-photon emission computed tomography and quantitative gated single photon emission computed tomography software program. Visual evaluation of perfusion was performed as well as analysis of motion with thickening function [expressed as summed rest score, summed motion score, and summed thickening score (STS)] with calculation of ejection fraction (EF) and lung-to-heart (L/H) ratio. Eight patients underwent 67Ga scintigraphy. Clinical, echocardiography, and cardiac enzymes (creatinine kinase-MB, myoglobulin, troponin T, brain natriuretic peptide) data were gathered from the patients' charts. Clinical outcome was grouped according to prognosis. Spearman's correlation (SC) test was used for comparison analysis.

Results: Myocardial perfusion defects were observed in eight patients. Perfusion defects in the left ventricle involve a mean of 7.25% (range: 1-11%), whereas wall motion abnormality on G-MPS was more prominent, which showed to be a better marker for myocardial inflammation and necrosis. The 67Ga scintigraphy findings were normal in all, but two. The G-MPS EF (33+/-21%) was slightly lower than the echocardiography EF (40+/-15%), but with close correlation (SC coefficient: 0.635). Comparison of scintigraphic findings with clinical parameters showed that summed motion score with G-MPS EF and STS with L/H ratios were highly correlated (0.932 and 0.622, respectively). The maximum brain natriuretic peptide and L/H ratio with STS were highly correlated with the patients' outcomes (SC coefficient: -0.621, 0.821, and 0.579, respectively), as well.

Conclusion: Tc-methoxyisobutylisonitrile G-MPS is therefore helpful in providing additional diagnostic and prognostic information in patients with myocarditis.
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http://dx.doi.org/10.1097/MNM.0b013e328303359fDOI Listing
October 2008

[(11)C]Choline positron emission tomography/computed tomography for staging and restaging of patients with advanced prostate cancer.

Nucl Med Biol 2008 Aug;35(6):689-95

Department of Nuclear Medicine, Klinikum rechts der lsar, Technische Universität München, Munich, Germany.

Introduction: To evaluate [(11)C]Choline positron emission tomography (PET)/computed tomography (CT) for staging and restaging of patients with advanced prostate cancer and to compare the diagnostic performance of PET, CT and PET/CT.

Methods: Forty-five consecutive patients with advanced prostate cancer underwent [(11)C]Choline-PET/CT between 5/2004 and 2/2006.

Results: Overall, 295 lesions were detected: PET alone, 178 lesions; diagnostic CT, 221 lesions; PET/CT (low-dose CT), 272 lesions; PET/CT (diagnostic CT), 295 lesions. Two thirds of the lesions were located in the bone; one third in the prostate, lymph nodes, periprostatic tissue and soft tissue (lung, liver). The use of diagnostic CT did not result in a statistically significant difference with respect to lesion localization certainty and lesion characterization (P=.063, P=.063). PET-negative but PET/CT-positive lesions were mostly localized in the bone (78%, 91/117) as were PET-positive and CT-negative lesions (72%, 53/74). Of the latter, 91% (48/53) represented bone marrow and 9% (5/53) cortical involvement.

Conclusions: Staging and restaging with [(11)C]Choline PET/CT in patients with advanced prostate cancer improve the assessment of local and regional recurrent as well as metastatic disease including skeletal manifestations. [(11)C]Choline PET/CT (with a low-dose CT) results in improved localization and lesion characterization. [(11)C]Choline PET/CT provides an added value for skeletal manifestations. [(11)C]Choline PET/CT changed disease management in 11 (24%) of 45 patients with advanced prostate cancer.
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http://dx.doi.org/10.1016/j.nucmedbio.2008.05.006DOI Listing
August 2008

Correspondence: diagnostic accuracy of 18F-FDG PET/CT in characterizing ovarian lesions.

Authors:
Murat Tuncel

Nucl Med Commun 2007 Nov;28(11):879-80; author reply 880

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http://dx.doi.org/10.1097/MNM.0b013e3282f12698DOI Listing
November 2007