A Frequency and Semiquantitative Analysis of Pathological 68Ga DOTATATE PET/CT Uptake by Primary Site–Dependent Neuroendocrine Tumor Metastasis

Abstract

Ga DOTATATE PET/CT is very useful in the localization of NEN primary tumors. Ga DOTATATE PET/CT allows for visualizations of bone and lymph node metastases, not detected by any other modalities, which provides better staging and changes the clinical decision in approximately one third of patients.Our study shows that pancreatic NEN presented statistically a significantly lower frequency of bone metastases in comparison to lung and intestinal NEN. No significant frequency of metastases in the liver and lymph nodes based on primary tumors was observed.

68Ga-DOTATATE Compared with 111In-DTPA-Octreotide and Conventional Imaging for Pulmonary and Gastroenteropancreatic Neuroendocrine Tumors: A Systematic Review and Meta-Analysis

“…These 17 studies included 971 participants (median, 44; Inter-quartile range, 22, 51; average age, 56 y [95% CI, 56– 66], with 3 reporting direct comparison of 68 Ga-DOTATATE with octreotide and conventional imaging (14-16), 9 studies comparing 68 Ga-DOTATATE with conventional imaging (17-25), and 5 studies reporting comparison of 68 Ga-DOTATATE with other radiopharmaceuticals without other direct imaging comparator but which were retained for reporting safety, toxicity, and method of 68 Ga-DOTATATE synthesis and administration (26-30). Of the 17 included studies, 8 (47%) were retrospective (14,17,19,21,22,26-28), 8 were prospective (15,17,18,23,25,29-31), and 1 (20) did not report the data collection method. Eight studies (47%) did not blind interpreters, 4 performed some level of blinding, and the remaining 5 did not report their blinding methods.…”

“…The number of patients receiving 68 Ga-DOTATATE, and whether the patients were receiving short-acting or long-acting octreotide medication at the time of the scan, are also shown. Only 1 study’s administered peptide mass was more than 50 μg (29), with the lowest mass ranging from 2 to 13 μg (22). Activity was under 220 MBq except in 1 study reporting 165–243 MBq (14).…”

“…Deppen et al (16), Etchebehere et al (18), and Kunikowska et al (29) were the only investigators reporting adverse events ( n = 6). One subject had postscan tachycardia resolving without treatment (16); 2 had mild, unexplained symptoms determined by the local institutional review board to not be serious or related to the research (18); 2 with a history of gastritis reported abdominal pain associated with 68 Ga-DOTATATE administration (effectively treated with an antispasmodic drug) (29); and the sixth subject (18) reported unilateral whole-body edema ipsilateral to the injected upper extremity, occurring within 24 h of injection and resolving spontaneously in less than 48 h, with no other sequelae, and not directly observed by medical staff. This last adverse event was determined by the local institutional review board to not be serious but possibly related to the research.…”

“…This last adverse event was determined by the local institutional review board to not be serious but possibly related to the research. Glucose testing among insulinoma patents found no changes in glucose levels (29). …”

Brain metastases: neuroimaging

“…Lastly, PET ligands that may have specificity for primary tumor types, such as prostate carcinoma (Chakraborty et al, 2015) and neuroendocrine tumors (Kunikowska et al, 2014), also are being investigated, but are in very early stages of development.…”