The utility of 18 F-FDG PET and PET/CT in the diagnosis and staging of chondrosarcoma: a meta-analysis.

OBJECTIVE: Chondrosarcoma is the second most common primary bone sarcoma; however, unlike other tumors, the biopsy cannot easily make a definite diagnosis or predict the histological grade. This meta-analysis was performed to evaluate the utility of 18 F-FDG PET and PET/CT to differentiate chondrosarcoma from benign cartilaginous lesions and to predict the histopathological grade of chondrosarcoma.

MATERIAL AND METHODS: A comprehensive search was performed in three electronic databases including Medline/PubMed, the Cochrane Library and Embase to retrieve diagnostic studies evaluating the role of 18 F-FDG PET or PET/CT for appraising the status of chondrosarcoma. Reference lists of related articles were also scrutinized manually. Useful data were extracted to calculate the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), the summary receiver operating characteristic curve (sROC), and the area under the curve (AUC) of 18 F-FDG PET or PET/CT in diagnosing chondrosarcoma, and pooled weighted mean differences (WMD) of maximum standardized uptake value (SUVmax) between different entities of cartilaginous neoplasms by using Stata 19.0.

RESULTS: A total of twelve studies provided sufficient data for the quantitative analysis. For the diagnosis of chondrosarcoma, the pooled sensitivity, specificity, and DOR of 18 F-FDG PET were 0.84 (95% confidence interval [CI] 0.46 to 0.97), 0.82 (95% CI 0.55 to 0.94), and 24.244 (95% CI 1.985 to 96.148), respectively while those of 18 F-FDG PET/CT were 0.94 (95% CI 0.86 to 0.97), 0.89 (95% CI 0.82 to 0.93), and 112.999 (95% CI 41.341 to 308.866), respectively. The pooled WMD of SUVmax were - 0.89 (95% CI -1.67 to -0.10) between benign cartilaginous lesions and grade 1 (G1) chondrosarcoma, -1.94 (95% CI -2.76 to -1.12) between G1 and grade 2 (G2) chondrosarcoma, and - 2.37 (95% CI -5.79 to 1.05) between G2 and grade 3 (G3) chondrosarcoma.

CONCLUSIONS: In a word, 18 F-FDG PET/CT revealed excellent accuracy in the diagnosis of chondrosarcoma and might assist in clinical decision-making. Meanwhile, although SUVmax alone showed restricted ability to differentiate benign cartilaginous lesions and G1 chondrosarcoma, as well as between G2 and G3 chondrosarcoma, it can identify intermediate/high-grade chondrosarcoma from low-grade ones.

LEVEL OF EVIDENCE: Level I evidence, a summary of meta-analysis.