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

Abstract

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 wallwas considered as PET positive and referred for further quantitative measurement. SUVmax on ED ((1f)SUVmax, (2f)SUVmax, (3f)SUVmax, (4f)SUVmax, and (5f)SUVmax for 5 frames), WB (WBSUVmax), and AD PET ((AD)SUVmax) 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 PETwas significantly higher than that of WB (P = 0.002) andADPET (P = 0.008). On ED PET, (2f)SUVmax 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 (WB)SUVmax and (AD)SUVmax (P = 0.043 and P = 0.007). Conclusions: Early dynamic PET can help to detect and characterize bladder cancer.