Biphasic GA 68-labeled prostate specific membrane antigen-11 positron emission tomography/computed tomography scans in the differential diagnosis and risk stratification of initial primary prostate cancer.

Background: This study aimed to assess the value of biphasic GA 68-labeled prostate-specific membrane antigen-11 (Ga-PSMA-11) positron emission tomography/computed tomography (PET/CT) scan in the differential diagnosis and risk stratification of initial primary prostate cancer (PCa).

Methods: A total of 51 patients with PCa (8 low- and intermediate-risk PCa patients and 43 high-risk PCa patients) and 36 patients with benign prostate lesions, who underwent standard whole-body imaging and delayed pelvic imaging of Ga-PSMA-11 PET/CT, were enrolled in this prospective study. The PET parameters, such as maximum and mean standard uptake value (SUVmax and SUVmean), and maximum and mean standard retention index of PET images were calculated and compared in different prostate lesions. The diagnostic performances of the PET parameters were evaluated by receiver operating characteristic (ROC) curves.

Results: All the PET parameters of PCa participants were significantly higher than those of participants with benign prostate lesions (P<0.001). The SUVmean of delayed imaging had the best performance in the diagnosis of PCa with an area under the curve (AUC) of 0.918 (95% CI: 0.858 to 0.977), the sensitivity of 90.0%, and specificity of 83.3%. The SUVmax and SUVmean of high-risk PCa participants were significantly higher than those of low- and intermediate-risk PCa participants (P<0.005). The SUVmax of standard imaging had the best performance in predicting high-risk PCa with an AUC of 0.890 (95% CI: 0.799 to 0.980), a sensitivity of 76.7%, and a specificity of 100.0%.

Conclusions: The biphasic Ga-PSMA-11 PET/CT scan had good performance in discriminating prostate cancer from benign prostate diseases. The SUVmean of the prostate lesion at delayed imaging of Ga-PSMA-11 PET/CT had the best value in the differential diagnosis of PCa, and the SUVmax at standard imaging was most valuable in predicting the risk stratification of PCa.