18F-PSMA-1007 PET/MR imaging, quantification and radiomics in the primary staging of prostate cancer and response prediction after neoadjuvant hormonal therapy

Prostate-specific membrane antigen (PSMA) is a cell-surface glycoprotein overexpressed on prostate cancer (PCa) cells. At present, PSMA PET is the gold standard to localize disease in patients with biochemically recurrent PCa and guides treatment in this clinical scenario. However, the role of PSMA PET in primary staging and its effect on patient management and outcome has only been studied in a limited number of mostly retrospective studies. Currently, conventional imaging (CT abdomen-pelvis and bone scan) is used in primary staging of patients with intermediate or high-risk PCa. It is known that CT and MRI have a low sensitivity for detecting lymph node (LN) metastases. In the last few years, several clinical nomograms were developed to evaluate the a-priori risk of LN metastases, however these lack adequate performance. So, extended pelvic lymph node dissection (ePLND) is still commonly performed in these patient groups to prevent under-staging. But it must be noted that an oncological benefit of LN removal has not been proven and that there is a non-negligible morbidity risk. With this project, we want to (i) demonstrate the accuracy of PSMA PET/MRI for identifying pelvic metastatic disease prior to radical prostatectomy with ePLND in patients with primary intermediate or high-risk PCa; (ii) compare the accuracy of PSMA PET/MRI and conventional imaging for identifying pelvic and distant metastatic disease in patients with primary intermediate or high-risk PCa; (iii) assess the impact of PSMA PET/MRI on patient management and outcome in the setting of primary and recurrent intermediate or high-risk PCa. In conclusion, we want to validate the role of PSMA PET in primary staging by investigating the accuracy of this imaging modality in this setting, its role in risk stratification as well as its effect on patient management and outcome.