The role of F-18-FDG PET/CT for the diagnosis and follow-up of relapsing polychondritis

Background RP is a rare autoimmune disorder which is associated with inflammation in cartilages,tissues throughout the body and much remains to be elucidated. PET/CT,as one of imaging techniques used to evaluate RP,have been previously reported in case reports.At present, PET/CT does not have a well-established role in the asseement of patients with RP, and future prospective studies are required to define the cost-effectiveness and clinical impact in this patient group more accurately. Objectives To investigate retrospectively the role of PET/CT for the diagnosis and follow-up of RP. Methods PET/CT findings were reviewed in six patients with RP.The initial PET/CT scans were performed 1 h and 2 h after FDG injection in all six patients. Follow- up PET/CT scans were performed during or followings teroid therapy in five patients. Results The initial PET/CT scans revealed intense FDG uptake by RP in all six patients.The maximum standardized uptake value increased in six patients. The lesions of abnormal FDG uptake were: tracheal/bronchial cartilage (n=6), costicartilage(n=4),nasal cartilage(n=4), cricoid cartilage(n=4),arytenoid cartilage (n=3),thyroid cartilage(n=3), auricular cartilage (n=3). The intense uptake in the cartilage reduced or disappeared during or following steroid therapy in five patients. Conclusions PET/CT enables the acquisition of all the carilages images and provides function information ,it has valuable role in assessing all the carilages and detecting RP,guiding the selection of a biopsy site and monitoring respone to treatment.