Oral Presentation The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2017

Role of 68Gallium Dotatate-PET/CT in pre-operative assessment of phaeochromocytoma and paraganglioma (#151)

Matti Gild 1 , Jeremy Hoang 2 , Edward Hsiao 2 , Geoffrey Schembri 2 , Roderick Clifton-Bligh 1
  1. Endocrinology Department, Royal North Shore Hospital, St Leonards, NSW, Australia
  2. Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia

Diagnosis of paragangliomas (PGL) and phaeochromocytomas (PC) is challenging.  The size, precarious location and functional heterogeneity of these rare neuroendocrine tumours subject patients to multiple investigations often yielding ambiguous results.  Failure to diagnose can lead to preoperative morbidity and mortality as well as incomplete staging.  Catecholamine assays are first line in assessment but are not helpful in non-functioning tumours and structural imaging with MRI and CT has limited specificity.  PET/CT radiopharmaceuticals have been successfully employed to diagnose and stage neuroendocrine tumours.  Somatostatin receptor imaging (SRI) agents have the highest sensitivity for these tumours, particularly the DOTA family of radiopharmaceuticals labelled with 68Gallium. We performed a retrospective analysis of all patients with PC and/or PGL at Royal North Shore Hospital, Sydney between 2012 and 2017 who had preoperative SRI with 68Gallium Dotatate PET/CT.  The number of cases included 58 PCs and 29 PGLs.   SRI was performed in 39 PCs (67.2%) and in 28 (96.5%) PGLs.  Sensitivity for this modality was 97.4% for PC and 95.8% for PGL.   Metastases were found in 25.6% PCs vs 25% PGLs.  Multifocal disease was identified in 3% PCs vs 33.3% PGLs.  Incidental findings from SRI including thyroid nodules, parathyroid adenomas or incidental primary or metastatic neuroendocrine tumours, were identified in 10.3% PCs and 20.8% PGLs.   The application of SRI changed management in the majority of cases (79.5% PC and 55.2% PGL).   We recommend that SRI scanning should be performed as first line to confirm the diagnosis of neuroendocrine tumours.   Preoperative scanning should be performed in patients with phaeochromocytomas >5cm to exclude metastases and in all patients with hereditary paragangliomas syndromes to exclude multifocal disease.  SRI using PET/CT is recommended for its superior quality, simple application lower cost and lower radiation than other commercially available analogues.