Total-body [ 68 Ga]Ga-PSMA-11 PET/CT improves detection rate compared with conventional [ 68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer

Purpose The purpose of this study was to assess whether total-body [ 68 Ga]Ga-PSMA-11 PET/CT could improve the detection rate compared with conventional [ 68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer. Methods Two hundred biochemical recurrent prostate cancer patients with similar clinicopathological characteristics were included, of whom 100 patients underwent early total-body [ 68 Ga]Ga-PSMA-11 PET/CT and diuretic-delayed total-body [ 68 Ga]Ga-PSMA-11 PET/CT, and the other 100 patients received early conventional [ 68 Ga]Ga-PSMA-11 PET/CT and diuretic-delayed conventional [ 68 Ga]Ga-PSMA-11 PET/CT. The detection rates of total-body [ 68 Ga]Ga-PSMA-11 PET/CT and conventional [ 68 Ga]Ga-PSMA-11 PET/CT were compared using a chi-square test and stratified analysis. The image quality of total-body [ 68 Ga]Ga-PSMA PET/CT and conventional [ 68 Ga]Ga-PSMA-11 PET/CT was compared based on subjective scoring and objective parameters. Subjective scoring was conducted from background noise and lesion prominence using a 5-point scale. Objective parameters were evaluated by SUVmax, SUVmean, the standard deviation (SD) of SUV, and the signal-to-noise ratio (SNR) of liver and gluteus maximus. The SUVmax of the recurrent lesions was also measured. Results The liver SD of the total-body [ 68 Ga]Ga-PSMA-11 PET/CT was significantly lower than that of conventional [ 68 Ga]Ga-PSMA-11 PET/CT, the SNR was significantly higher than that of conventional [ 68 Ga]Ga-PSMA-11 PET/CT, and the subjective evaluation was significantly better than that of conventional [ 68 Ga]Ga-PSMA-11 PET/CT. The detection rate of total-body [ 68 Ga]Ga-PSMA PET/CT for biochemical recurrence of prostate cancer was significantly higher than that of conventional [ 68 Ga]Ga-PSMA-11 PET/CT (91.0% vs. 74.0%, P = 0.003). Total-body [ 68 Ga]Ga-PSMA-11 PET/CT had better detection efficiency for patients with a Gleason score ≤ 8 or PSA ≤ 2 ng/ml. The advantages of diuretic-delayed total-body [ 68 Ga]Ga-PSMA-11 PET/CT were more obvious. Conclusion Total-body [ 68 Ga]Ga-PSMA-11 PET/CT could significantly improve the detection rate compared with conventional [ 68 Ga]Ga-PSMA-11 PET/CT in patients with biochemical recurrent prostate cancer.