Spectrum of Physiologic and Pathologic Skeletal Muscle (18)F-FDG Uptake on PET/CT.

OBJECTIVE: Skeletal muscle (18)F-FDG uptake on PET/CT can be either physiologic or related to a variety of different pathologic conditions. FDG PET/CT can be used for assessment of primary and metastatic tumors and infective or inflammatory conditions affecting the musculature. CONCLUSION: In this article, we describe the various causes and patterns of skeletal muscle FDG uptake. Familiarity with these patterns is essential for proper interpretation of clinical FDG PET/CT images.

Evaluation of (68)Ga-DOTANOC PET/CT imaging in a large exclusive population of pancreatic neuroendocrine tumors.

PURPOSE: To evaluate the diagnostic accuracy of (68)Ga-DOTANOC PET/CT imaging in a large exclusive population of pancreatic neuroendocrine tumors (NETs). METHODS: Data of 141 (mean age 46.2 ± 15.2 years) patients who underwent 178 (68)Ga-DOTANOC PET/CT studies for diagnosis/staging (n = 88) and restaging (n = 90) of pancreatic NET were retrospectively analyzed. PET/CT results were compared to conventional imaging (CIM) when available (n = 86). Histopathology and/or clinical/imaging follow-up (minimum 6 months) were used as reference standard. RESULTS: The overall sensitivity, specificity, and accuracy of (68)Ga-DOTANOC PET/CT were 85.7%, 79.1%, and 84.8%. The corresponding values were 73%, 50%, and 70.4% for diagnosis/staging groups and 98.6%, 100%, and 98.8% for restaging groups. The accuracy was significantly higher for restaging as compared to diagnosis/staging (P < 0.0001) and in non-insulinoma tumors than insulinomas (P < 0.0001). The SUVmax of primary tumors was significantly higher than metastatic lesions overall (P = 0.001), as well as in diagnosis/staging (P = 0.041) and restaging (P = 0.0003) subgroups. When available, CIM was less specific than (68)Ga-DOTANOC PET/CT (P < 0.001) and showed fewer lesions. CONCLUSIONS: (68)Ga-DOTANOC PET/CT is useful for diagnosis/staging and restaging of patients with pancreatic NET. It demonstrates more lesions compared to CIM and is more specific.

Comparison of the prognostic values of 68Ga-DOTANOC PET/CT and 18F-FDG PET/CT in patients with well-differentiated neuroendocrine tumor.

PURPOSE: To determine the prognostic value of (68)Ga-DOTANOC PET/CT in patients with well-differentiated neuroendocrine tumor (NET), and to compare the prognostic value with that of (18)F-FDG PET/CT and other conventional clinicopathological prognostic factors. METHODS: Data from 37 consecutive patients (age 46.6 ± 13.5 years, 51% men) with well-differentiated NET who underwent (68)Ga-DOTANOC PET/CT and (18)F-FDG PET/CT were analyzed. All patients underwent a baseline visit with laboratory and radiological examinations. Clinical and imaging follow-up was performed in all patients. Progression-free survival (PFS) was measured from the date of the first PET/CT scan to the first documentation of progression of disease. RESULTS: (68)Ga-DOTANOC PET/CT was positive in 37 of the 37 patients and (18)F-FDG PET/CT was positive in 21. During follow-up 10 patients (27%) showed progression of disease and 27 (73%) showed no progression (24 stable disease, 3 partial response). The median follow-up was 25 months (range 2 - 52 months). Among the variables evaluated none was significantly different between the progressive disease and nonprogressive disease groups, with only SUVmax on (68)Ga-DOTANOC PET/CT being borderline significant (P = 0.073). In the univariate analysis for PFS outcome, SUVmax on (68)Ga-DOTANOC PET/CT (HR 0.122, 95% CI 0.019 - 0.779; P = 0.026) and histopathological tumor grade (HR 4.238, 95% CI 1.058 - 16.976; P = 0.041) were found to be associated with PFS. Other factors including age, sex, primary site, Ki-67 index, TNM stage, (18)F-FDG PET/CT status (positive/negative), SUVmax on (18)F-FDG PET/CT and type of treatment were not significant. In multivariable analysis, only SUVmax on (68)Ga-DOTANOC PET/CT was found to be an independent positive predictor of PFS (HR 0.122, 95% CI 0.019 - 0.779; P = 0.026). CONCLUSION: SUVmax measured on (68)Ga-DOTANOC PET/CT is an independent, positive prognostic factor in patients with well-differentiated NET and is superior to SUVmax on (18)F-FDG PET/CT and conventional clinicopathological factors for predicting PFS.

Diuretic 18F-FDG PET/CT imaging for detection and locoregional staging of urinary bladder cancer: prospective evaluation of a novel technique.

PURPOSE: Positron emission tomography/computed tomography (PET/CT) with (18)F-fluorodeoxyglucose (FDG) has been used with limited success in the past in primary diagnosis and locoregional staging of urinary bladder cancer, mainly because of the pharmacokinetics of renal excretion of (18)F-FDG. In the present prospective study, we have evaluated the potential application of diuretic (18)F-FDG PET/CT in improving detection and locoregional staging of urinary bladder tumours. METHODS: Twenty-five patients suspected of having primary carcinoma of the urinary bladder were evaluated prospectively for diagnosis and staging. All of these 25 patients underwent conventional contrast-enhanced computed tomography (CECT) of the abdomen/pelvis and whole-body diuretic (18)F-FDG PET/CT. In addition, pelvic PET/CT images were obtained using the special technique of forced diuresis using intravenous furosemide (20-40 mg). Of the 25 patients, 10 underwent radical cystectomy and 15 underwent transurethral resection of the bladder tumour (TURBT). Results of CECT and diuretic (18)F-FDG PET/CT were compared considering histopathology as a reference standard. RESULTS: Of the 25 patients, CECT detected a primary tumour in 23 (sensitivity 92 %), while (18)F-FDG PET/CT was positive in 24 patients (sensitivity 96 %). Mean size and maximum standardized uptake value of the bladder tumours were 3.33 cm (range 1.6-6.2) and 5.3 (range 1.3-11.7), respectively. Of the 25 patients, only 10 patients underwent radical cystectomy based on disease status on TURBT. Among those ten patients, nine had locoregional metastases. Among the nine patients who had positive lymph nodes for metastasis on histopathology, CECT and PET/CT scan had a sensitivity of 44 and 78 %, respectively. (18)F-FDG PET/CT was found to be superior to CECT in the detection of the primary tumour and locoregional staging (p < 0.05). CONCLUSION: Diuretic (18)F-FDG PET/CT is highly sensitive and specific and plays an important role in improving detection of the primary tumour and locoregional staging of urinary bladder tumours. Diuretic (18)F-FDG PET/CT demonstrated a higher diagnostic value when compared with CECT in these patients.

Divergent role of (68)Ga-labeled somatostatin analogs in the workup of patients with NETs: AIIMS experience.

Neuroendocrine tumors (NETs) encompass a wide range of rare and heterogeneous neoplasms arising from the neural crest. Diagnosis of NETs is conventionally done by a combination of common clinical symptoms and biochemical evidence of hormonal excess, which these tumors are known to secrete. After a diagnosis of NET is established, a search for its localization is carried out using common morphologic imaging methods such as ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). The main problem with structural imaging is, however, its inability to distinguish between endocrine and exocrine lesions. Functional imaging of NETs started with use of iodine-131-meta-iodobenzylguanidine ((131)I-MIBG) and has come a long way since. From accurate demonstration of functioning tumors to detection of small and occult lesions, functional imaging has penetrated almost every aspect of NET management. Procedures such as (131/123)I-MIBG, (111)In-Octreoscan and others are rapidly giving way to use of PET/CT based on the superior resolution of the system and the availability of target-specific positron-emitting radiotracers. The availability of (68)Ga from generator-based radionuclide systems, namely (68)Ge/(68)Ga generators, opened up a new era of molecular imaging for NETs. A multitude of somatostatin analogs can be easily radioliganded with (68)Ga using heterocyclic macromolecular bifunctional chelating systems for targeted diagnosis of somatostatin receptor-expressing tumors, used most effectively to date for detection of NETs. This chapter focuses on our experience at the All India Institute of Medical Sciences, New Delhi regarding the divergent roles of (68)Ga-labeled somatostatin analogs in the workup of patients with NETs.

Diagnostic performance of somatostatin receptor PET/CT using 68Ga-DOTANOC in gastrinoma patients with negative or equivocal CT findings.

PURPOSE: Contrast-enhanced CT (CECT) is a standard investigative procedure in the localization of gastrinomas. Small tumors are often missed and metastatic lesions may remain occult on CT. The purpose of present study was to prospectively evaluate the diagnostic performance of (68)Ga-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI(3)-Octreotide ((68)Ga-DOTANOC) positron emission tomography/computed tomography (PET/CT) in gastrinoma patients with negative or equivocal CT findings. METHODS: Twenty-five patients (age 46.6 ± 13.3 years; male 60%) with clinical/biochemical diagnosis of gastrinoma and negative or equivocal findings on CECT were prospectively evaluated. All of them underwent (68)Ga-DOTANOC PET/CT which was evaluated by two nuclear medicine physicians in consensus. Combination of histopathology, serum gastrin, endoscopy, and follow-up imaging were taken as reference standard. RESULTS: (68)Ga-DOTANOC PET/CT was positive in 17 patients and negative in 8 patients, yielding an overall detection rate of 68%. It was positive 13/20 patients who underwent baseline evaluation and in 4/5 post-treatment patients. Of the 11 patients who had a negative CT result, (68)Ga-DOTANOC PET/CT was positive in four cases (detection rate 36.4%), while it was abnormal in 13/14 patients who had equivocal CT findings (detection rate 92.8%). Diagnostic performance of (68)Ga-DOTANOC PET/CT was superior in patients with equivocal CECT findings than that in patients with negative CECT (P = 0.010). CONCLUSION: (68)Ga-DOTANOC PET/CT appears to be useful in patients with gastrinoma with negative or equivocal results on CECT, especially the latter group.

Prospective evaluation of 68Ga-DOTA-NOC PET-CT in phaeochromocytoma and paraganglioma: preliminary results from a single centre study.

OBJECTIVE: To evaluate the role of (68)Ga-labelled [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-NaI(3)-Octreotide ((68)Ga-DOTA-NOC) whole body positron emission tomography-computed tomography (PET-CT) as a functional imaging approach for phaeochromocytoma and paraganglioma. METHODS: Thirty-five unrelated patients (Median age-34.4 years; range: 15-71) were evaluated in this prospective study. PET-CT was performed after injection of 132-222 MBq of (68)Ga-DOTA-NOC. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as quantitatively (standardised uptake value-SUVmax). In addition we compared the findings with (131)I Metaiodobenzylguanidine (MIBG) scintigraphy, which was available for 25 patients. Histopathology and/or conventional imaging with biochemical markers were taken as the reference standard. RESULTS: 44 lesions were detected on (68)Ga-DOTA-NOC PET-CT imaging with an additional detection of 12 lesions not previously known, leading to a change in management of 6 patients. Sensitivity, specificity and accuracy were 100%, 85.7%, and 97.1% on a per patient basis and 100%, 85.7% and 98% on per lesion basis, respectively.(131)I MIBG scintigraphy was concordant with (68)Ga-DOTA-NOC PET-CT in 16 patients and false negative in 9 patients. CONCLUSION: (68)Ga-DOTA-NOC PET-CT is highly sensitive and specific for the detection of phaeochromoctyomas and paragangliomas. It seems better than (131)I MIBG scintigraphy for this purpose. KEY POINTS: • ( 68 ) Ga-DOTA-NOC PET-CT seems useful in patients with phaeochromocytoma and paraganglioma. • This prospective single centre study showed that it has high diagnostic accuracy. • (68) Ga-DOTA-NOC PET-CT seems superior to (131) I-MIBG in these patients.

Isolated cardiac metastasis in a patient with neuroendocrine carcinoma of pancreas discovered on 68Ga-DOTANOC PET/CT.

We present an interesting image that demonstrates utility of (68)Ga-DOTANOC PET/CT for demonstrating rare metastatic sites of neuroendocrime tumor.

Spectrum of 18F-FDG PET/CT findings in patients presenting with fever of unknown origin.

OBJECTIVE: The objective of this article is to provide an illustrative tutorial highlighting the clinical utility of (18)F-FDG PET/CT for imaging patients presenting with fever of unknown origin (FUO). CONCLUSION: FDG PET/CT is a powerful tool in localizing an inciting source in patients with FUO. The high sensitivity of FDG PET/CT for diagnosing infective, inflammatory, and neoplastic processes can be exploited in this setting because these processes are often the common causes of FUO.

Role of (68)Ga-DOTATOC PET-CT in the diagnosis and staging of pancreatic neuroendocrine tumours.

OBJECTIVE: The objective of the present study was to evaluate the role of (68)Ga-DOTA(0)-Phe(1)-Tyr(3)-octreotide ((68)Ga-DOTATOC) positron emission tomography computed tomography (PET-CT) for detection and staging of pancreatic neuroendocrine tumours (NETs). METHODS: Twenty patients with clinically suspected and/or histopathologically proven pancreatic NET underwent (68)Ga-DOTATOC PET-CT imaging for staging and /or localisation of primary lesion. They also underwent contrast enhanced CT (CECT) and 8 patients underwent (18)F-FDG PET-CT. SUVmax of primary and metastatic lesions were measured. Results were verified with histopathology for primary tumour and with clinical follow up/MRI and /or biopsy for metastatic disease. Results of (68)Ga-DOTATOC PET-CT were compared to CECT and (18)F-FDG PET-CT. RESULTS: (68)Ga-DOTATOC PET-CT correctly localised primary in all 20, CECT in 15 and (18)F-FDG PET-CT in 2 patients. (68)Ga-DOTATOC PET-CT demonstrated metastases in 13 patients, CECT in 7 and (18)F-FDG PET-CT in 2. (68)Ga-DOTATOC PET-CT emerged as the best investigation with 100% sensitivity and PPV for detecting primary tumour and metastatic disease. The detection rate of CECT was lower than (68)Ga-DOTATOC PET-CT, both for primary tumour (20vs.15) or metastatic disease (13vs.7). (18)F-FDG PET-CT performed poorly for primary and metastasis. CONCLUSION: Ga-DOTATOC PET-CT is a very useful imaging investigation for diagnosing and staging pancreatic NET.

Gallium-68-DOTA-NOC PET/CT of patients with gastroenteropancreatic neuroendocrine tumors: a prospective single-center study.

OBJECTIVE: The objective of this study was to evaluate the role of (68)Ga-labeled [1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid]-1-NaI(3)-octreotide (DOTA-NOC) PET/CT in the diagnosis and management of gastroenteropancreatic neuroendocrine tumors (NETs). SUBJECTS AND METHODS: One hundred nine patients (median age, 50 years) with gastroenteropancreatic NETs underwent (68)Ga-DOTA-NOC PET/CT. PET/CT was performed after injection of 132-222 MBq (4-6 mCi) of (68)Ga-DOTA-NOC. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as quantitatively (maximum standardized uptake value [SUV(max)]). Results of PET/CT were compared with the results of conventional imaging. Histopathology results, when available, and follow-up PET/CT or conventional imaging with biochemical markers were considered to be the reference standards. RESULTS: Gallium-68-DOTA-NOC PET/CT showed sensitivity and specificity of 78.3% and 92.5%, respectively, for primary tumor and 97.4% and 100% for metastases. It was better than a conventional imaging modality for the detection of both primary tumor (p < 0.001) and metastases (p < 0.0001). It changed the management strategy in 21 patients (19%) and supported management decisions in 32 patients (29%). CONCLUSION: Gallium-68-DOTA-NOC PET/CT appears to be a highly sensitive and specific modality for the detection of gastroenteropancreatic NET. It is better than conventional imaging for the evaluation of gastroenteropancreatic NETs and can have a significant impact on patient management.

Does left ventricular diastolic function deteriorate earlier than left ventricular systolic function in anthracycline cardiotoxicity?

Cardiotoxicity is the most important complication in patients receiving anthracycline chemotherapy. We studied the left ventricular diastolic function (LVDF) and systolic function (LVSF) in these patients and assessed whether LVDF deteriorates earlier than LVSF. We prospectively studied 58 patients (mean age 48.02 ± 13.87; 32 female, 26 male) on anthracycline treatment, before chemotherapy (S0) and after cumulative doses of 139 ± 12 mg/m(2) (S1) and 308 ± 14 mg/m(2) (S2). The LVSF was computed in terms of left ventricular ejection fraction (LVEF) from equilibrium radionuclide angiography (ERNA). The peak ejection rate (PER), peak filling rate (PFR), time to peak ejection rate (TPER), time to peak filling rate (TPFR), 1/3rd filling fraction and ratio of PFR and PER were calculated from ERNA and were also standardized using 150 baseline ERNA studies. Statistical analysis was done by repeated measures analysis of variance (ANOVA). We found significant decrease in LVEF (P<0.001) and PER (P<0.001) between the S1 and S2 studies and PFR (P<0.007) between the S0 and S1 studies. In conclusion in patients receiving anthracycline treatment, LVDF deteriorates earlier than left ventricular systolic function (LVSF).

Right Ventricle Metastasis from Carcinoma Rectum: Findings on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Rectal adenocarcinoma metastasizes most commonly to the lungs and liver. Metastasis to heart, although described in literature, is a very rare phenomenon. We describe the 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) findings of a 45-year-old male who was a biopsy-proven case of adenocarcinoma rectum. Apart from metastatic disease involving liver, lungs, bone marrow, and lymph nodes, metastasis to right ventricle was also seen on PET-CT scan.

Ileal Neuroendocrine Tumor With Bilateral Breast and Ovarian Metastases: Findings on 68Ga-DOTANOC PET/CT Scan.

Metastasis to the breast is a rare occurrence and constitutes less than 2% of all breast tumors. Similarly, ovarian metastases from neuroendocrine tumors are also uncommon, and if the adnexal masses are bilateral, then the chances of it being metastatic rather than being primary range from 88% to 94%. We present a case of 61-year-old woman who in the course of workup for abdominal pain and diarrhea was eventually diagnosed as ileal neuroendocrine tumor with breast, ovarian, and lymph nodal metastases on Ga-DOTANOC PET/CT scan.

Elastofibroma Dorsi: Findings on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Elastofibroma dorsi (EFD) is a relatively rare soft-tissue pseudotumor that arises from mesenchymal tissue. We present a case of 48-year-old woman who underwent 18F fluorodeoxyglucose (FDG) positron emission tomography-computed tomography for initial staging of suspected carcinoma of the left breast. Incidental detection of soft-tissue masses showing moderate FDG uptake was seen in the bilateral infrascapular location characteristic of EFD.

Occult breast primary malignancy presenting as isolated axillary lymph node metastasis - early detection of primary site by 18F-FDG PET/CT.

Breast cancer patients rarely present with isolated axillary lymph node metastasis without any clinical or radiological evidence of primary tumor. Identification of the primary site of tumor helps in planning appropriate patient management which has definite impact on patient's survival. We present here a case of 30-year-old female who presented with isolated right axillary lymph node metastasis with no evidence of primary tumor clinically. Conventional imaging modalities were negative for primary site. She underwent whole body 18F-Flurodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and it contributed significantly in early detection of occult primary tumor in right breast.

Accuracy of 68Ga DOTANOC PET/CT Imaging in Patients With Multiple Endocrine Neoplasia Syndromes.

OBJECTIVE: The aim of this study was to evaluate the role of 68Ga DOTANOC PET/CT imaging in patients with multiple endocrine neoplasia (MEN) syndromes. PATIENTS AND METHODS: Data of 33 patients (age, 33.5 [13.8] years; male 14/female 19) with MEN syndromes (MEN 1, 9; MEN 2A, 19; MEN 2B, 5) who underwent 41 68Ga DOTANOC PET/CT studies were retrospectively analyzed. Twenty PET/CTs were done for staging and 21 for restating. PET/CT images were evaluated in consensus by 2 nuclear medicine physicians, qualitatively and semiquantitatively (SUV(max)). A combination of histopathology, clinical, and biomarker follow-up was taken as reference standard. RESULTS: Of the total 41 68Ga DOTANOC PET/CTs, 34 were interpreted as positive for neuroendocrine tumors (NETs) and 7 as negative. The patientwise sensitivity of PET/CT was 94% (95% confidence interval [CI], 80-99), specificity was 71% (95% CI, 29-96), positive predictive value was 94% (95% CI, 80-99), negative predictive value was 71% (95% CI, 29-96), and accuracy was 90%. A total of 74 disease sites were demonstrated on PET/CT, including 41 primary NETs (pancreas, 10; stomach, 2; pheochromocytoma, 10; medullary thyroid carcinoma, 19), 31 metastatic sites (lymph node, 15; liver, 10; bone, 4; lung, 1; breast, 1), and 2 parathyroid adenomas. Lesionwise sensitivity, positive predictive value, and accuracy of PET/CT were 93%, 96%, and 90% overall, 89%, 95%, and 85% for primary tumors, and 100%, 97%, and 97% for metastasis, respectively. Among primary tumors, the SUV(max) of medullary thyroid carcinoma was significantly lower than gastro pancreatic NETs (P = 0.003) and pheochromocytomas (P = 0.003). No site-specific difference was seen in SUV(max) of metastatic lesions. CONCLUSIONS: 68Ga DOTANOC PET/CT shows high diagnostic accuracy in MEN syndrome and can demonstrate both primary and metastatic NETs in these patients.

18F-FDG PET/CT imaging features of Rosai Dorfman disease: a rare cause of massive generalized lymphadenopathy.

Rosai Dorfman disease (RDD) or sinus histiocytosis is a rare non-neoplastic idiopathic disease characterized by massive lymphadenopathy in young adults. Extranodal involvement is seen in 25%-43% cases. RDD is usually self-remitting. However, it mimics lymphoproliferatve disorders clinically as well as on imaging. We present the F-FDG PET/CT findings in a 46-year-old female patient with nodal RDD.

(18)F-FDG PET/CT for initial assessment and response monitoring in a case of high grade primary lymphoma of the thyroid gland: A case report and review of literature.

Thyroid lymphoma is a rare disease entity of elderly females. Chronic lymphocytic thyroiditis is said to be the precursor of thyroid lymphoma, suggesting a role of chronic antigen stimulation in the development of the disease. We present a case of male with lymphocytic thyroiditis who presented with painless progressive neck enlargement and pathology revealed features of high grade lymphoma. Staging and posttreatment (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) was performed. This report reemphasizes the role of (18)F-FDG PET/CT in the diagnosis, staging, and assessment of therapy response in patients with extranodal lymphoma, including the primary thyroid lymphoma.

Dual tracer functional imaging of gastroenteropancreatic neuroendocrine tumors using 68Ga-DOTA-NOC PET-CT and 18F-FDG PET-CT: competitive or complimentary?

OBJECTIVE: This study aimed to compare the diagnostic performance of Ga-DOTANOC PET/CT with F-FDG PET/CT in the patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). PATIENTS AND METHODS: Data of 51 patients with definite histological diagnosis of GEP-NET who underwent both Ga-DOTA-NOC PET-CT and F-FDG PET-CT within a span of 15 days were selected for this retrospective analysis. Sensitivity, specificity, and predictive values were calculated for Ga-DOTA-NOC PET-CT and F-FDG PET-CT, and results were compared both on patientwise and regionwise analysis. RESULTS: Ga-DOTA-NOC PET-CT is superior to F-FDG PET-CT on patientwise analysis (P < 0.0001). On regionwise analysis, Ga-DOTA-NOC PET-CT is superior to F-FDG PET-CT only for lymph node metastases (P < 0.003). Although Ga-DOTA-NOC PET-CT detected more liver and skeletal lesions compared with F-FDG PET-CT, the difference was not statistically significant. In addition, the results of combined imaging helped in selecting candidates who would undergo the appropriate mode of treatment, whether octreotide therapy or conventional chemotherapy CONCLUSIONS: Ga-DOTA-NOC PET-CT seems to be superior to F-FDG PET-CT for imaging GEP-NETs. However, their role seems to be complementary because combination of Ga-DOTA-NOC PET-CT and F-FDG PET-CT in such patients helps demonstrate the total disease burden and segregate them to proper therapeutic groups.