Equivocal bone lesions on PSMA PET/CT: systematic review and meta-analysis on their prevalence and malignancy rate

Prostate-specific membrane antigen (PSMA) PET/CT has an established reliable diagnostic performance for detecting metastases in prostate cancer. However, there are increasing instances of scans demonstrating equivocal bone lesions, with non-specific uptake and without a definite benign or malignant CT correlate. To date, the prevalence, malignancy rate, and relationship with radioligand type ([18F] PSMA-1007 vs. others ([68Ga]Ga-PSMA-11 and [18F] DCFPyL) for these equivocal lesions have not been extensively established. A systematic review and meta-analysis was conducted on equivocal bone lesions. Pubmed and EMBASE were searched up to December 11, 2023. Quality of the studies was evaluated using QUADAS-2. The following proportions were pooled using random-effects model: (1) prevalence of equivocal bone lesions (i.e., number of patients with one or more equivocal bone lesions/number of patients with PSMA PET/CT) and (2) their malignancy rates (i.e., number of metastases/number of equivocal bone lesions). Subgroup analyses based on radioligand type, clinical setting, and definition of equivocal bone lesion were performed. Twenty-five studies (4484 patients) were included. Pooled prevalence of equivocal bone lesions was 20