Predictive value of 68Ga-PSMA PET/CT for high-risk prostate cancer / 中华核医学与分子影像杂志

ABSTRACT

Objective To investigate the value of 68Ga-prostate specific membrane antigen (PSMA)-617 PET/CT in predicting high-risk prostate cancer.Methods From May 2016 to January 2017,30 patients (median age 67 years) with biopsy-proven prostate cancer were included.The 68Ga-PSMA-617 PET/CT images and clinical data of all patients were analyzed retrospectively.According to prostate cancer risk stratification criteria of National Comprehensive Cancer Network (NCCN) Guidelines (including Gleason scores,prostate specific antigen (PSA)),all patients were classified into low-moderate-risk group and high-riak group.PET images were analyzed semi-quantitatively and maximum standardized uptake value (SUVmax) of primary prostate cancer was measured.SUVmax of 68Ga-PSMA-617 PET/CT was used to establish logistic regression model for predicting high-risk prostate cancer,and the diagnostic efficiency of the model was evaluated by receiver operating characteristic (ROC) curve analysis.Results The median Gleason score of 30 patients was 7.5 (7,9),and the median PSA was 34.0 (19.4,119.1) μg/L,including 9 patients with PSA≤ 20 μg/L and 21 patients with PSA＞20 μg/L.According to the NCCN Guidelines,there were 24 patients with high-risk prostate cancer and 6 patients with low-moderate-risk prostate cancer.SUVmax was higher in high-risk group than that in low-moderate-risk group (14.2 (11.4,23.1) vs 7.9 (3.8,13.1);u =118,P＜ 0.05).Logistic regression model established with SUVmax could effectively predict high-risk prostate cancer with the area under ROC curve of 0.819.When the cut-off value was set as 0.73,the sensitivity and specificity of the model were 87.5％(21/24) and 4/6 respectively.Conclusion SUVmax of 68Ga-PSMA-617 PET/CT can be used as an imaging biomarker for predicting high-risk prostate cancer.