Determinants of the uptake of the uncinate process of pancreas in Ga-DOTATOC PET/CT: a retrospective study.

Purpose: an increased uptake of the uncinate process of pancreas (UPP) has been described in about one-third of somatostatin receptor imaging procedures and may hinder image interpretation. The determinants of this uptake are however poorly understood. The aim of this study was to investigate the impact of cold somatostatin analogues (cSA) on UPP Ga-DOTATOC uptake. Age and diabetic status were also studied.

Methods: all adult patients who performed a Ga-DOTATOC PET/CT in our center between May 2021 and April 2023 were retrospectively screened. For each one, UPP uptake was visually assessed and measured using SUVmax. Clinical data including cSA medication, age and diabetic status were collected. Univariate and multivariate analyses were conducted using logistic regression. SUVmax comparisons were conducted using a Mann-Whitney Wilcoxon test.

Results: 82 patients were included. UPP uptake was significantly lower in patients treated with cSA (OR 0.27, p = 0.015 in multivariate analysis), with a lower SUVmax (4.97 vs. 8.81, p = 0.001). No significant result was found regarding diabetic status or age.

Conclusion: cold somatostatin analog treatment decreased the physiological UPP uptake in Ga-DOTATOC PET/CT. This effect could be used to reduce interpretation errors in this location.