68Ga-DOTATOC Versus 68Ga-DOTATATE PET/CT in Functional Imaging of Neuroendocrine Tumors (original) (raw)
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68Ga-DOTATATE PET/CT in Nonneuroendocrine Tumors
Clinical Nuclear Medicine, 2017
PET-CT with somatostatin analogs labeled with 68 Ga is increasingly recognized as the best imaging modality for the evaluation of welldifferentiated neuroendocrine tumors (NETs). However, somatostatin receptor (SSR) is not an exclusive marker for NET. A variety of tumors other than NETs express SSR, leading to a significant risk of false-positive PET/CT results. We illustrate false-positive 68 Ga-DOTATATE PET/CT findings due to high uptake by non-Hodgkin lymphoma, metastatic meningioma, breast cancer, thyroid adenoma, and papillary carcinoma. Although 68 Ga-DOTATATE is a noteworthy tracer for oncological application, pathological conditions with overexpression of SSR should be recognized to prevent misinterpretation of PET/CT images.
European Journal of Nuclear Medicine and Molecular Imaging, 2012
Purpose Recent studies have suggested that positron emission tomography (PET) imaging with 68 Ga-labelled DOTAsomatostatin analogues (SST) like octreotide and octreotate is useful in diagnosing neuroendocrine tumours (NETs) and has superior value over both CT and planar and single photon emission computed tomography (SPECT) somatostatin receptor scintigraphy (SRS). The aim of the present study was to evaluate the role of 68 Ga-DOTA-1-NaI 3 -octreotide ( 68 Ga-DOTANOC) in patients with SST receptor-expressing tumours and to compare the results of 68 Ga-DOTA-D-Phe 1 -Tyr 3 -octreotate ( 68 Ga-DOTATATE) in the same patient population. Methods Twenty SRS were included in the study. Patients' age (n 020) ranged from 25 to 75 years (mean 55.4 ± 12.7 years). There were eight patients with well-differentiated neuroendocrine tumour (WDNET) grade1, eight patients with WDNET grade 2, one patient with poorly differentiated neuroendocrine carcinoma (PDNEC) grade 3 and one patient with mixed adenoneuroendocrine tumour (MANEC). All patients had two consecutive PET studies with 68 Ga-DOTA-TATE and 68 Ga-DOTANOC. All images were evaluated visually and maximum standardized uptake values (SUV max ) were also calculated for quantitative evaluation. Results On visual evaluation both tracers produced equally excellent image quality and similar body distribution. The physiological uptake sites of pituitary and salivary glands showed higher uptake in 68 Ga-DOTATATE images. Liver and spleen uptake values were evaluated as equal. Both 68 Ga-DOTATATE and 68 Ga-DOTANOC were negative in 6 (30 %) patients and positive in 14 (70 %) patients. In 68 Ga-DOTANOC images only 116 of 130 (89 %) lesions could be defined and 14 lesions were missed because of lack of any uptake. SUV max values of lesions were significantly higher on 68 Ga-DOTATATE images. Conclusion Our study demonstrated that the images obtained by 68 Ga-DOTATATE and 68 Ga-DOTANOC have comparable diagnostic accuracy. However, 68 Ga-DOTA-TATE seems to have a higher lesion uptake and may have a potential advantage.
Ga-68 DOTATATE PET/CT in Neuroendocrine Tumors: Initial Experience
Journal of Postgraduate Medicine Education and Research, 2013
Introduction: Neuroendocrine tumors (NET) are a heterogeneous group of neoplasms, majority of which express somatostatin (SST) receptors. Recently, with the widespread use of positron emission tomography/computed tomography (PET/CT) and development of novel PET tracers like Ga-68 DOTA peptide which specifically bind to somatostatin receptors (SSTR), Ga-68 DOTA peptide PET/CT is used in management of NET. Objective: To study the various indications for which Ga-68 DOTATATE PET/CT scan was performed and the utility of the scans. Materials and methods: Retrospective evaluation of the patients data was performed who underwent Ga-68 DOTATATE PET/CT as part of their diagnostic workup between June 2011 and July 2012. A total of 145 patients aged 1 to 71 years (mean: 37.4 years) were studied during this period. Results: Ga-68 DOTATATE PET scan was positive in 23/39 patients referred for characterization or diagnosis, in 6/19 patients for localization, in 13/24 patients for detection of unknown NET primary, in 16/17 patients for staging, in 6/7 patients for recurrence assessment, 12/12 patients for response evaluation, 7/18 patients in restaging and in 5/5 differentiated thyroid cancer patients with thyroglobulin elevated but negative iodine scan. Conclusion: Ga-68 DOTATATE PET/CT is a useful modality in characterization, localization, detection of unknown NET primary, staging, restaging, recurrence and response evaluation to treatment in patients with NET.
The diagnostic role of 68Ga-DOTATATE PET/CT in the detection of neuroendocrine tumours
Nuclear Medicine Review, 2011
BACKGROUND: Positron emission tomography (PET) combined with computer tomography (CT) using 68 Ga-DOTATATE is a promising method for the evaluation of patients with recognised or suspected neuroendocrine tumours (NET). The aim of this study was to assess the diagnostic value of 68 Ga-DOTATATE PET/CT in the visualisation of the expression of somatostatin receptors (SSTR) and identification of new lesions. MATERIAL AND METHODS: Between December 2009 and January 2011 ninety-seven patients with confirmed (88 cases) or suspected (9 cases) NET underwent 68 Ga DOTATATE PET/CT. The primary, confirmed or suspected, NET localizations were: GEP tumours-71 patients; medullary thyroid carcinoma-4 patients; cancer of an unknown primary-14 patients; and NET in other localisations-8 patients. PET/CT acquisitions were performed using standard techniques,
Journal of Nuclear Medicine, 2013
Somatostatin receptor PET tracers such as [ 68 Ga-DOTA, 1-Nal 3 ]-octreotide ( 68 Ga-DOTANOC) and [ 68 Ga-DOTA,Tyr 3 ]octreotate ( 68 Ga-DOTATATE) have shown promising results in patients with neuroendocrine tumors, with a higher lesion detection rate than is achieved with 18 F-fluorodihydroxyphenyl-Lalanine PET, somatostatin receptor SPECT, CT, or MR imaging. 68 Ga-DOTANOC has high affinity for somatostatin receptor subtypes 2, 3, and 5 (sst 2,3,5 ). It has a wider receptor binding profile than 68 Ga-DOTATATE, which is sst 2 -selective. The wider receptor binding profile might be advantageous for imaging because neuroendocrine tumors express different subtypes of somatostatin receptors. The goal of this study was to prospectively compare 68 Ga-DOTANOC and 68 Ga-DOTATATE PET/CT in the same patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and to evaluate the clinical impact of 68 Ga-DOTANOC PET/CT. Methods: Eighteen patients with biopsy-proven GEP-NETs were evaluated with 68 Ga-DOTANOC and 68 Ga-DOTATATE using a randomized crossover design. Labeling of DOTANOC and DOTATATE with 68 Ga was standardized using a fully automated synthesis device. PET/CT findings were compared with 3-phase CT scans and in some patients with MR imaging, 18 F-FDG PET/CT, and histology. Uptake in organs and tumor lesions was quantified and compared by calculation of maximum standardized uptake values (SUVmax) using volume computer-assisted reading. Results: Histology revealed low-grade GEP-NETs (G1) in 4 patients, intermediate grade (G2) in 7, and high grade (G3) in 7. 68 Ga-DOTANOC and 68 Ga-DOTATATE were false-negative in only 1 of 18 patients. In total, 248 lesions were confirmed by crosssectional and PET imaging. The lesion-based sensitivity of 68 Ga-DOTANOC PET was 93.5%, compared with 85.5% for 68 Ga-DOTATATE PET (P 5 0.005). The better performance of 68 Ga-DOTANOC PET is attributed mainly to the significantly higher detection rate of liver metastases rather than tumor differentiation grade. Multivariate analysis revealed significantly higher SUVmax in G1 tumors than in G3 tumors (P 5 0.009).
2019
Objective(s): In view of somatostatin receptor (SSR) expression on cell membranes of the majority of neuroendocrine tumors (NETs), functional imaging exploiting analogs of SSR alongside the anatomical imaging is the mainstay of this diagnostic modality. In this prospective study, we assessed and directly compared the diagnostic parameters of 68Ga-DOTATATE PET/CT and 99mTc-Octreotide SPECT/CT, as well as CT/MRI. Methods: Twenty-five NET patients, either histologically proven or highly suspicious for NET, who were referred for Octreotide Scan were enrolled in this prospective study. They all underwent 99mTc-Octreotide SPECT/CT and then 68Ga-DOTATATE PET/CT. A blind interpretation was conducted for each imaging as well as for the previously obtained conventional imaging (CT or MRI). The patient-based and lesion-based analysis were conducted and the results of the three modalities were compared. The histopathologic confirmation or follow-up data were considered as the gold standard. Als...
Standardized uptake values of 68Ga-DOTANOC PET: a promising prognostic tool in neuroendocrine tumors
2010
Despite the fact that several studies have been published regarding the prognostic factors of neuroendocrine tumors (NETs), there are some cases in which available data are not sufficient to predict disease progression and to define a correct therapeutic approach. To our knowledge, the role of maximum standardized uptake value (SUVmax) as a prognostic factor has never been studied in NET patients. Therefore, we prospectively investigated whether 68 Ga-[1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI3-octreotide (68 Ga-DOTANOC) PET SUVmax could be used as an accurate noninvasive marker for disease prognosis. Methods: Forty-seven patients with NETs were studied with 68 Ga-DOTANOC PET. All patients underwent a baseline visit and laboratory and radiologic examinations. Follow-up was performed in all cases. Results: SUVmax was significantly higher in patients with pancreatic NET and in those with well-differentiated NETs. Moreover, SUVmax was significantly higher in patients with an elevated expression of 2A-somatostatin receptor. During the follow-up, the disease was stable or presented a partial response in 25 patients, and in 19 cases the disease progressed. The patients with stable disease or a partial response had an SUVmax significantly higher than did those in the progressive disease group, with the best cutoff ranging from 17.9 to 19.3. At univariate and multivariate analysis, the significant positive prognostic factors were welldifferentiated NET, an SUVmax of 19.3 or more, and a combined treatment with long-acting somatostatin analogs and radiolabeled somatostatin analogs. Conclusion: We demonstrated, for the first time to our knowledge, that 68 Ga-DOTANOC PET SUVmax correlates with the clinical and pathologic features of NETs and is also an accurate prognostic index.