Rapid-sequence MRI for long-term surveillance for paraganglioma and phaeochromocytoma in patients with succinate dehydrogenase mutations.

INTRODUCTION: Patients with SDHx mutations need long-term radiological surveillance for the development of paragangliomas and phaeochromocytomas, but no longitudinal data exist. We assessed the performance of rapid-sequence non-contrast magnetic resonance imaging (MRI) in the long-term monitoring of patients with SDHx mutations. METHODS: Retrospective study between 2005-2015 at a University Hospital and regional endocrine genetics referral center. Clinical and imaging data of forty-seven patients with SDHx mutations [SDHB (36), SDHC (6), SDHD (5)] who had surveillance for detection of paragangliomas by rapid-sequence non-contrast MRI (base of skull to pubic symphysis) were collected. RESULTS: Twelve index cases (9 SDHB, 1 SDHC, 2 SDHD) and 35 mutation-positive relatives were monitored for a mean of 6.4 years (range 3.1 to 10.0 years). Mean age at the end of the study: SDHB 46.9+/-17.6 years; SDHC 42.3+/-24.4 years; SDHD 54.9 +/- 10.6 years. Excluding imaging at initial diagnosis of index cases forty-three patients underwent 116 rapid-sequence MRI scans: 83 scans were negative and 31 scans were positive for a sPGL/HNPGL in 13 patients. Most patients had multiple scans [n=number of patients (number of rapid-sequence MRI scans during screening)]; n=9 (2), n=20 (3), n=6 (4), n=1 (6). Nine patients (3 index) were diagnosed with new paragangliomas during surveillance and non-operated tumour size was monitored in 9 patients. There were two false positive scans (1.6%). Scans were repeated every 27 +/- 9 months. CONCLUSIONS: Biannual rapid-sequence non-contrast MRI is effective to monitor patients with SDHx mutations for detection of new tumours and monitoring of known tumours.