AB1550 UTILITY OF WHOLE-BODY 18F-FDG PET-CT IN THE DIAGNOSIS OF NEUROSARCOIDOSIS

Background Neurosarcoidosis (NS) is one of the most severe manifestations sarcoidosis [ 1]. NS diagnosis difficult since clinical features and cranial imaging findings are often unspecific central nervous system biopsy unfrequently performed. Flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET-CT) emerging as a powerful tool for evaluation sarcoidosis. Data on role 18F-FDG PET-CT in scarce. Objectives To assess utility patients with suspected NS. Methods Patients diagnosed at University hospital Northern Spain, between January 1999 December 2019 were assessed. Sarcoidosis was according to ATS/ERS/WASOG criteria follows: compatible radiological presentation, histopathologic confirmation, exclusion other granulomatous diseases. Consortium Consensus Group 2]. Receiver Operating Characteristic (ROC) curve Chest Computed Tomography (CT) compared. Results 30 (19 women/11 men) out 384 (7.8%) (mean age; 55.0±15.8 years). The underlying neurological chronic headache (n=13; 43.4%), peripheral neuropathy (n=6, 20%), (n=5, 16.7%), spinal cord abnormalities (n=3, 10%) aseptic meningitis 10%). Complementary study’s described Table 1 . performed 10 (33.4%) patients. abnormal 9 (90%) Abnormalities suggestive found 7 (70%) These located lymph nodes (n=7, 100%), parotid gland (n=1, 14.3%) bone 14.3%). Other 2 (20%) vocal 50%) rectum 50%). Only (10%) patient had no PET-CT. All (n=2, 100%) which chest radiography CT negative, pathological After whole-body PET-CT, all accessible underwent node 71.4%), skin In them non-necrotizing granulomas found. diagnostic ability compared ( Figure ). higher Area Under Curve (AUC) (0.94 [95% CI: 0.78-1]) than (0.75 0.28-1]). Conclusion seems be useful specially when negative or inconclusive. References: ] Riancho-Zarrabeitia L, et al. Clin Exp Rheumatol 2014; 32:275-84. Stern BJ, JAMA Neurol. 2018;75:1546-1553. 1. studies neurosarcoidosis 1999-2019 period Spain. Ancillary investigation With (n=10; 33.4%) Without (n=20; 66.6%) Total (n=30; • Laboratory tests, No./No. assessed (% ) - ACE >70 U/L 3/9 (33.3) 9/13 (60) 12/24 (50) CRP >0.5 mg/dL 3/10 (30) 8/10 (80) 11/20 (55) ESR >20 mm/h 5/10 7/15 (46.7) 12/25 (48) CD4/CD8 >3.5 1/2 0/1 (0) 1/3 (33.4) Imaging sarcoidosis, radiograph 16/20 24/30 9/10 (90) 25/30 (83.4) Gammagraphy 6/9 (66.7) 10/18 (55.6) 16/27 (59.3) Abbreviations: PET-CT: tomography, ACE: Angiotensin-Converting Enzyme, CRP: C-reactive protein, CT: computerized ESR: Erythrocyte Sedimentation Rate. Acknowledgements: NIL. Disclosure Interests Alba Herrero-Morant: None declared, Lara Sanchez-Bilbao: Iñigo Gonzalez-Mazon: David Martínez-López: Carmen Álvarez-Reguera: José Luis Martín-Varillas Grant/research support from: AbbVie, Pfizer, Lilly, Janssen, UCB, Celgene, Raúl Fernández-Ramón: Ricardo Blanco Speakers bureau: Abbvie, Roche, Bristol-Myers, Galapagos MSD, Consultant of: Janssen Novartis Roche.