[68Ga]Ga-DOTANOC Uptake at Pancreatic Head/Uncinate Process: Is It a Persistent Diagnostic Pitfall Over Time?

Abstract

Purpose: [68Ga]Ga-DOTA-peptide uptake in the pancreatic head/uncinate process (UP) is a frequent PET/CT finding. Although mostly physiologic, it can represent a pitfall in PET/CT reading, especially when focal. An increased frequency of UP uptake has been reported in patients (pts) affected by diabetes mellitus (DM). The aim of the study is to describe the frequency of [68Ga]Ga-DOTANOC UP uptake to evaluate its variations over time and its possible correlation with DM. Methods: In September 2017, a monocentric prospective observational electronic archive was initiated at our center to collect clinical and imaging data of pts undergoing [68Ga]Ga-DOTANOC PET/CT. Among the pts enrolled in the first 6 months (Sept 2017 to Feb 2018), those presenting [68Ga]Ga-DOTANOC PET/CT uptake at UP level were included. Pts with UP lesions already documented on CT/MRI or those that underwent surgical excision of UP before PET/CT were excluded from the analysis. [68Ga]Ga-DOTANOC UP uptake was classified as diffuse or focal and compared with the pattern observed in previous PET/CT scans performed at our center. An increased frequency of UP uptake was also correlated with the presence of DM. Results: In the first 6 months, 253 pts were enrolled in the archive and 172 out of them were included in the analysis. UP increased uptake was frequently observed (77/172, 44.8%) and was mostly diffuse (62/77). In 75/172 pts (43.6%), previous [68Ga]Ga-DOTANOC PET/CT scans were available (overall 268 scans; number of previous PET per pt range: 1–20) and were retrospectively reviewed. Despite the fact that, in most pts, the uptake pattern was stable over time (54/75 pts, 72%), it changed in approximately one third of cases (21/75, 28%). Among DM pts (29/172), only 10/29 (34.4%) presented increased UP uptake. Conclusions: UP [68Ga]Ga-DOTANOC uptake is a frequent non-malignant finding (slightly higher than previously reported), mostly presenting with a diffuse pattern. However, contrary to previous reports, our data show that the pattern of uptake may vary over time in approximately one third of the cases and it is not more frequently observed in pts with DM.

Advancements in Neuroendocrine Neoplasms: Imaging and Future Frontiers

“…DOTA PET/CT substantially improves the sensitivity and specificity of NEN detection, achieving 80% to 98% detection rates [5,47], even in cases of lesions affecting the DOTA PET/CT substantially improves the sensitivity and specificity of NEN detection, achieving 80% to 98% detection rates [5,47], even in cases of lesions affecting the lymph nodes, bones, liver, and peritoneum (Figure 9). Conversely, when assessing poorly differentiated NENs or tumors with high proliferative activity, PET/CT with 18-fluoro-2deoxyglucose (18F-FDG) is the favored option [13,46,48].…”

“…lymph nodes, bones, liver, and peritoneum (Figure 9). Conversely, when assessing poorly differentiated NENs or tumors with high proliferative activity, PET/CT with 18-fluoro-2deoxyglucose (18F-FDG) is the favored option [13,46,48]. In general, [68Ga]DOTATATE PET/CT exhibits superior diagnostic performance when compared to [18F]F-FDG PET/CT, which typically shows a lower sensitivity in the range of 50% to 70% (Figure 10) [40,49].…”

“…The NETPET score is a system used to evaluate and grade NETs combining findings at [68Ga]Ga-DOTA-peptides and [18F]F-FDG PET/CT into a single parameter. This score typically ranges from P0 to P5.…”

“…The emerging radiopharmaceuticals fluorine-labeled SST receptor-agonists ([18F]F-AlF-NOTA-Octreotide and [18F]F-SiFAlin-TATE) and [64Cu]Cu-SARTATE offer practical advantages over existing options [65,66]. SST receptor antagonists like [68Ga]Ga-OPS202 show favorable biodistribution and higher detection rates, particularly at the liver level [67]. [68Ga]Ga-NODAGA-LM3 and [68Ga]Ga-DOTA-LM3 are promising SST receptor 2-antagonists for NETs [68].…”

“…SST receptor antagonists like [68Ga]Ga-OPS202 show favorable biodistribution and higher detection rates, particularly at the liver level [67]. [68Ga]Ga-NODAGA-LM3 and [68Ga]Ga-DOTA-LM3 are promising SST receptor 2-antagonists for NETs [68]. [68Ga]Ga-Exendin is employed for detecting insulinomas, which are DOTATATE negative in up to 50% of the cases given low SST receptor 2 expression, and [18F]F-meta-fluorobenzylguanidine ([18F]F-MFBG) shows encouraging results for neuroblastoma imaging [69].…”