“…Before pooling diagnostic values, we screened the PET parameters of each study according to the principle of data extraction. Among all included studies, the most effective parameter was the maximum tumor-to-brain ratio (TBRmax) in 10 studies ( 10 , 11 , 16 , 28 , 30 , 31 , 33 , 36 , 38 , 39 ), the mean tumor-to-brain ratio (TBRmean) in 3 studies ( 34 , 37 , 40 ), and the relative change of TBR in 2 studies ( 27 , 29 ). In the 5 remaining studies ( 9 , 12 , 26 , 32 , 35 ), the most effective parameter was the metabolic tumor volume (MTV), slope, standardized uptake values of the lesion divided by standardized uptake values of the normal (nSUVmax), radiomics signature, and combined parameter ( Table 1 ), respectively.…”