Enhanced Application of ¹⁸F-FDG PET/CT in Bladder Cancer by Adding Early Dynamic Acquisition to a Standard Delayed PET Protocol

Purpose We investigated the value of early dynamic (ED) PET for the detection and characterization of bladder cancer. Methods Fifty-Two bladder cancer patients were prospectively enrolled. The study protocol was composed of ED, whole-body (WB, 60 minutes after injection), and additional delayed (AD, 120 minutes after injection) PET acquisition. Early dynamic PET was acquired for 10 minutes and reconstructed as 5 frames at 2-minute intervals. A focal radiotracer accumulation confined to the bladder wall was considered as PET positive and referred for further quantitative measurement. SUVmax on ED (^1fSUVmax, ^2fSUVmax, ^3fSUVmax, ^4fSUVmax, and ^5fSUVmax for 5 frames), WB (^WBSUVmax), and AD PET (^ADSUVmax) were measured. PET results were correlated with bladder cancer pathology variables. Results The sensitivities of ED, WB, and AD PET for bladder cancer were 84.6%, 57.7%, and 61.2%, respectively. The sensitivity of ED PET was significantly higher than that of WB (P = 0.002) and AD PET (P = 0.008). On ED PET, ^2fSUVmax was significantly correlated with muscle invasiveness, histological grade, and pathological tumor size (P = 0.018, P = 0.030, and P = 0.030). On WB and AD PET, only pathological tumor size showed significant positive correlation with ^WBSUVmax and ^ADSUVmax (P = 0.043 and P = 0.007). Conclusions Early dynamic PET can help to detect and characterize bladder cancer.