The heart matters: a review of incidental cardiac uptake on Ga-68 DOTA peptide PET-CT scans.

Abstract

The aim of this study was to evaluate the frequency and relative significance of incidental cardiac uptake on 68Ga-DOTA-peptide PET-CT scans in patients with neuroendocrine tumours/genetic syndromes expressing somatostatin receptors. Scans of 1463 patients who underwent 68Ga-DOTA-peptide PET-CT scans in our department between 2013 and 2018 were retrospectively evaluated for the presence of uptake in the heart and/or its appendages. out of 1463 patients (1.3%) demonstrated uptake of radio-peptide in the heart and/or its appendages. In 18 out of these 19 patients, the clinicians were unaware of possible cardiac involvement (one patient was a known case of cardiac paraganglioma). The primary neuroendocrine tumours and genetic syndromes associated with those with cardiac uptake of 68Ga-DOTA-peptide were as follows: unknown primary (n = 7), small bowel (n = 6), colon (n = 2), caecum (n = 1), pancreas (n = 1), cardiac paraganglioma (n = 1), Von Hippel Lindau syndrome (n = 1). Amongst the patients with neuroendocrine tumours, demonstrating cardiac uptake of 68Ga-DOTA-peptide, there was no clear association with carcinoid heart disease. Our results are in agreement with established literature. The exact prognostic implication of cardiac involvement in patients with neuroendocrine tumours as well as other genetic syndromes expressing somatostatin receptors is unknown. We hypothesize that early detection and confirmation of cardiac metastasis(es) in these patients and introduction of different treatment regimes (such as Peptide Receptor Radionuclide Therapy), earlier in the course of the disease would reduce the disease burden on the heart and therefore contribute to better patient outcomes. Cardiac involvement is a rare and hitherto less well-studied occurrence in neuroendocrine tumours, with an incidence in the range of 1%. To assess the possible prognostic implications, further detailed multicentre studies are required.