Objective: This study aimed to evaluate fluorine-18 fludeoxyglucose positron emission tomography-CT ((18)F-FDG PET-CT) for the diagnosis, targeted biopsy and therapy of relapsing polychondritis (RP).
Methods: The literature pertaining to the use of (18)F-FDG PET-CT in patients with RP was retrieved from the Cochrane Library, PubMed, Excerpta Medica Database (EMBASE), China National Knowledge Infrastructure (CNKI) and Wanfang databases until July 2015. Clinical characteristics, auxiliary examination results, chest CT findings, tracheoscopy and biopsy findings, high metabolic activity lesions, maximum standardized uptake values, (18)F-FDG PET-CT-guided biopsy site, pathologic results of biopsy samples and alteration in high (18)F-FDG-uptake lesions after treatment were retrospectively analysed.
Results: 18 publications with 26 cases were enrolled. The five most common symptoms of patients with RP diagnosed with (18)F-FDG PET-CT were cough, fever, chest tightness, sore throat and arthralgia. Of the 26 patients, 23 patients had multiple and symmetric cartilage lesions with high metabolic activity, revealed by (18)F-FDG PET-CT. The disease mainly affected organs such as the bronchus, trachea, throat, costicartilage and auricle. The maximum standardized uptake values ranged from 1.93 to 13.03 (mean, 4.94). (18)F-FDG PET-CT revealed that patients with RP with tracheal and bronchial involvement had a close correlation with cough (χ(2) = 6.80, p = 0.006). (18)F-FDG PET-CT showed a significantly higher positive biopsy rate compared with bronchoscopy (χ(2) = 12.91, p < 0.001) for targeted lesions with high metabolic activity. Post-treatment re-examinations with (18)F-FDG PET-CT showed obvious subsidence or complete disappearance of high (18)F-FDG-uptake lesions in 13 cases, showing highly consistent symptom improvements.
Conclusion: (18)F-FDG PET-CT is likely to become a valuable imaging tool in the diagnosis and treatment of RP.
Advances in knowledge: The presence of symmetrically distributed high FDG-uptake lesions may be a criterion for the diagnosis of RP. (18)F-FDG PET-CT is useful for targeting biopsy sites, which remarkably increase the positive biopsy rate. Therefore, (18)F-FDG PET-CT may be of great value in the diagnosis and treatment of RP.