A recent study published in Cancers sought to determine the effectiveness of prostate-specific membrane antigen positron emission tomography (PSMA PET) compared with conventional imaging and liver biopsies in the detection of liver metastases in patients with castration-resistant prostate cancer (CRPC). The research group also evaluated a PSMA PET/computed tomography (CT)-based radiomic model able to identify liver metastases.
The multicenter retrospective study enrolled 60 patients with CRPC based on specific inclusion criteria. The patients must have been proven CRPC patients, PSMA PET and conventional imaging/liver biopsy must have been performed in a 6-month timeframe, and no therapy changes between PSMA PET and conventional imaging/liver biopsy must have been found.
The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PSMA PET for evaluating liver metastases was calculated. After extracting radiomic features, a prediction model for liver metastases identification was developed by the research group.
Within 6 months before or after PSMA PET, conventional imaging and liver biopsies identified 24 of the 60 patients (40%) with liver metastases. The sensitivity, specificity, PPV, NPV, and accuracy for liver metastases evaluated by PSMA PET were 0.58, 0.92, 0.82, 0.77, and 0.78, respectively. Liver metastases and maximum lesion diameter were both significantly associated with positive PSMA PET. In a multivariate regression analysis, the radiomic feature-based model combining sphericity and the moment of inverse difference had an area under the curve of 0.807 (95% CI, 0.686-0.920).
For the assessment of liver metastases, [68Ga]Ga-PSMA-11-PET was found to have moderate sensitivity and high specificity, PPV, and inter-reader agreement when compared with conventional imaging/liver biopsies in patients with CRPC.