¹⁸F-FDG PET/CT is a valuable tool for relapsing polychondritis diagnose and therapeutic response monitoring

To retrospectively investigate the role of (18) F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) for the diagnosis and therapeutic response in relapsing polychondritis (RP) patients.

(18)F-FDG PET/CT findings were reviewed in six RP patients. The initial scans were performed for all patients, follow-up scans were performed during steroid therapy for five patients. Changes in the abnormal lesions and the maximal standard uptake value (SUVmax) were analyzed.

The initial PET/CT scans revealed intense FDG uptake in the cartilages for all six patients. The lesions of abnormal FDG uptake were tracheal/bronchial cartilage (n = 4), costicartilage (n = 4), nasal cartilage (n = 3), cricoid cartilage (n = 3), auricular cartilage (n = 3), arytenoid cartilage (n = 3), thyroid cartilage (n = 2), hyoid cartilage (n = 1) and mediastinum lymph node (n = 1). The mean visual score and the mean SUVmax were 2.96 ± 0.20 and 4.10 ± 0.6. The intense uptake reduced or disappeared during steroid therapy for five patients, the mean visual score and the mean SUVmax were 1.58 ± 1.4 and 1.51 ± 1.4.

(18)F-FDG PET/CT enables the acquisition of both morphologic and glucose metabolic of the related cartilage structures. It plays a valuable role in assessing almost all cartilage and detecting RP, which is a better selection of a biopsy site as well as therapeutic response monitoring.