Comparing PSMA PET/CT and MRI-RSI for Finding and Outlining Tumors Inside the Prostate in Men With Newly Diagnosed Prostate Cancer

The detection and delineation of the intraprostatic tumor burden plays a crucial role in the personalized treatment of primary prostate cancer. The current gold standard multiparametric magnetic resonance imaging (mpMRI) is used to guide targeted prostate biopsies for initial diagnostic work up and for definitive focal dose-escalated radiotherapy in intermediate and high-risk prostate cancer patients. However, mpMRI might underestimate the tumor volume and manual gross tumor volume delineation based on mpMRI underlies significant interobserver variability. Thus, novel imaging modalities are warranted to increase the detection rate and/or decrease the interobserver variability during tumor delineation. This study will prospectively compare two promising advanced medical imaging methods: MRI-RSI and PSMA PET with the current gold-standard mpMRI for tumor detection and delineation in primary prostate cancer patients.