SFEBES2021 Oral Poster Presentations Endocrine Cancer and Late Effects (4 abstracts)
1Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford University Hospitals, Oxford, United Kingdom; 2Department of Radiology, Oxford University Hospitals, Oxford, United Kingdom; 3Department of Oncology, Oxford University Hospitals, Oxford, United Kingdom; 4Department of Hepato-Pancreato-Biliary surgery, Oxford University Hospitals, Oxford, United Kingdom
Gallium68-Dotatate PET-CT is a somatostatin-receptor (SSTR) based imaging modality employed in the diagnosis and follow-up of Neuroendocrine Tumours (NET). We set out to investigate the incidence of incidental findings, some of which are related to SSTR expression, in our NET patient cohort in Oxford University Hospital. Sixty-eight patients underwent Gallium68-Dotatate PET-CT between June 2020 and June 2021. 40 patients (59%) were female, and median age was 64 (24-86) years. The most common primary disease site was small intestine (27, 40%); 46 patients (68%) had metastases and 36 patients (53%) were on somatostatin analogue treatment at the time of data collection. Twenty patients (29%) had at least one incidental finding on Gallium68-Dotatate PET-CT. The most common incidental finding was avidity inside the calvarium suggestive of meningioma, noted in 7 patients (10%). Of these, 5 had cranial MRI or CT and a corresponding meningioma was found in just one case, for which no clinical intervention or follow-up was required. One patient had uptake in the iliac bone; biopsy did not reveal any malignancy, and review of subsequent CT suggested it may represent an area of fibrous dysplasia. Gallium68 uptake was present in the thyroid gland of four patients (6%), one of whom had a 15mm TR5 nodule and has opted for ultrasound surveillance. One patient had uptake in the pituitary, confirmed to be a non-functioning microadenoma. Another patient had uptake in the left ventricular wall; subsequent cardiac MRI was normal. Incidental findings of vertebral haemangiomata and wedge fracture were present in 3 and 1 patients, respectively. Incidental findings, unrelated to NET, are reported in almost one in three Gallium68-Dotatate PET-CT studies. Although rarely clinically significant, patients should be counselled about the possibility of incidental findings, and the potential need for further investigations including brain imaging.