TY - JOUR T1 - [18F]Florbetapir positron emission tomography: identification of muscle amyloid in inclusion body myositis and differentiation from polymyositis JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 657 LP - 662 DO - 10.1136/annrheumdis-2018-214644 VL - 78 IS - 5 AU - James B Lilleker AU - Richard Hodgson AU - Mark Roberts AU - Karl Herholz AU - James Howard AU - Rainer Hinz AU - Hector Chinoy Y1 - 2019/05/01 UR - http://ard.bmj.com/content/78/5/657.abstract N2 - Objectives With the tools available currently, confirming the diagnosis of inclusion body myositis (IBM) can be difficult. Many patients are initially misdiagnosed with polymyositis (PM). In this observational study at a UK adult neuromuscular centre, we investigated whether amyloid positron emission tomography could differentiate between IBM and PM.Methods Ten patients with IBM and six with PM underwent clinical review, [18F]florbetapir positron emission tomography and MRI of skeletal musculature. Differences in [18F]florbetapir standardised uptake value ratios in skeletal muscle regions of interest were evaluated. Relationships between [18F]florbetapir standardised uptake value ratios and measures of disease severity (clinical and by MRI of skeletal muscle) were assessed.Results [18F]florbetapir standardised uptake value ratios were significantly higher in those with IBM compared with PM for all assessed regions (total-[18F]florbetapir standardised uptake value ratio 1.45 (1.28 to 2.05) vs 1.01 (0.80 to 1.22), p=0.005). For total-[18F]florbetapir standardised uptake value ratiosā‰„1.28, sensitivity and specificity for IBM was 80% and 100%, respectively.Conclusions [18F]florbetapir amyloid positron emission tomography differentiates IBM from PM. Successful development could facilitate accurate diagnosis, inclusion in clinical trials and help avoid unnecessary exposure to potentially harmful treatments. ER -