Head-to-head comparison of [68Ga]Ga-FAPI PET and [18F]FDG PET in the detection of bone and lymph node metastasis in various cancers: A systematic review and meta-analysis

Purpose The aim of our meta-analysis and systematic review was to contrast the positivity rates of [68Ga]Ga-FAPI PET and [18F]FDG PET in detecting bone and lymph node metastases across diverse cancer types. Methods We conducted a comprehensive search for eligible articles up until August 2023, utilizing databases including PubMed, Embase, and Web of Science. Studies focusing on the positivity rate of [68Ga]Ga-FAPI PET vs. [18F]FDG PET for bone and lymph metastasis were included. Using random-effect model, the positivity rate for [68Ga]Ga-FAPI PET and [18F]FDG PET were generated. In order to gauge the heterogeneity among aggregated studies, we utilized the I2 statistic. Additionally, we applied the Quality Assessment of Diagnostic Performance Studies (QUADAS-2) methodology to evaluate the caliber of the studies encompassed in our analysis. Results A total of 430 publications were initially identified in the search. Eventually, 25 studies, involving 779 patients, met the inclusion criteria. In terms of bone metastasis, the findings indicate no statistically significant difference between the use of [68Ga]Ga-FAPI PET and [18F]FDG PET (P = 0.34). However, concerning lymph node metastasis, the results demonstrate significant difference between the two imaging agents (P = 0.04). Conclusions This systematic review suggests that [68Ga]Ga-FAPI PET appears to outperform [18F]FDG PET in detecting lymph node metastases. However, when it comes to bone metastasis, no statistically significant difference was observed. It is crucial to acknowledge that the insights concerning bone metastasis stem from studies with comparatively modest sample sizes. Consequently, there is a pressing demand for further, expansive prospective studies in this field.