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AB0970 Utility of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography for Early Diagnosis and Evaluation of Disease Activity of Relapsing Polychondritis

Background Relapsing polychondritis (RPC) is relatively rare, and early diagnosis is difficult. Objectives We investigated the utility of FDG-PET/CT for the diagnoses of RPC and evaluation of disease activity. Methods Five RPC patients undergoing FDG-PET/CT hospitalized in our hospital between 2006 and 2013 were studied. Eight RPC cases examined by PET reported in the literature were also assessed. Data from 13 patients total were analyzed. Results Typical FDG accumulation was noted in tracheobronchial trees of 9 patients, costal cartilage of 5, joints of 5, larynx of 4, nasal cavity/paranasal sinuses of 3, auricles of 3, lymph nodes of 3, and the aorta of 1. One patient showed nasal chondritis on PET scan despite absence of nasal changes on physical examination. Of 5 patients with costochondritis, 4 remained asymptomatic. Of 9 patients with airway FDG accumulation, 8 developed respiratory symptoms and all had CT abnormalities. In the other patient, airway FDG accumulation was evident despite the absence of airway symptoms and a lack of abnormalities in the respiratory function test and CT. PET also revealed bronchial chondritis in asymptomatic patients.In 5 patients with PET post-treatment, FDG accumulation had diminished with symptomatic and inflammatory improvement. Table 1. Non-enhanced CT findings during FDG PET/CT No. Lesion characteristics and location on CT and FDG PET/CT Nose, throat, and ear lesions Lung lesions Other lesions Uptake Shape on CT Uptake Shape on CT Uptake Shape on CT 1 No findings No findings Bronchus Tracheobronchial wall thickening No findings No findings 2 Auricle, annular cartilage, vocal cord No findings No findings Tracheobronchial wall thickening and stenosis Rib cartilage No findings 3 Auricle No findings No findings No findings lymph nodes, aorta, Joints lymph nodes swelling 4 Cavitas nasi and paranasal sinuses, pharynx Sinusitis Bronchus No findings Multiple joints No findings 5 Larynx, maxillary sinus No findings Bronchus Thickening of bronchi and lobar bronchi Joints Lymph nodes swelling 6 No findings No findings Trachea and bronchus Tracheal wall thickening and bronchostenosis No findings No findings 7 Nasal cartilage, laryngeal cartilage Swelling of laryngeal soft tissue Trachea and bronchus Smooth tracheal wall thickening Rib cartilage No findings 8 Auricle, cartilage of the auditory canal Inflammatory tissue filling the tympanic cavity and mastoid No findings No findings lymph nodes No findings 9 Hypopharynx No findings No findings Bronchial wall thickening All rib cartilage, sternal angle, joints No findings 10 Larynx No findings Trachea and bronchus Tracheobronchial wall thickening and stenosis All rib cartilage, lymph nodes lymph nodes swelling 11 Larynx n.d. Trachea and bronchus n.d. All rib cartilage n.d. 12 Larynx No findings Trachea and bronchus Tracheobronchial wall thickening No findings No findings 13 No findings No findings Trachea and bronchus Tracheobronchial wall thickening Joints No findings Conclusions FDG-PET/CT is a potentially powerful tool for the early diagnosis of RPC, especially in patients without easily biopsied organ involvement. This modality also facilitates the evaluation of extent of disease and disease activity during treatment. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1039