Grant: Project Grant

Radiotherapy plus hormonal treatment is the recommended form of treatment for men with high risk prostate cancer. An increase in the delivered treatment dose has been shown to improve treatment success rates in these patients. The downside, however, is increased treatment side-effects. The ASCENDE-RT trial, a recent multi-center randomized trial at the BC Cancer Agency, shows that men treated with external beam radiation therapy (EBRT) followed by low-dose-rate prostate brachytherapy (LDR-PB) boost had better treatment results compared to conventional dose-escalated EBRT (DE-EBRT). Though, worse side-effects, mostly in the form of urethral strictures, were also observed. LDR-PB is particularly well suited to target tumors of the prostate. However, since determining the tumor location cannot be reliably done (and, therefore, is usually not done) the extra-dose is given to a majority of the prostate gland. By identifying tumor locations and focusing higher treatment doses to these areas and a lower dose to healthy tissue (i.e. 'focal LDR-PB boost') we expect less treatment side-effects in men with high-risk prostate cancer. We propose to develop and evaluate a new alternative for treatment of high-risk prostate cancer which involves: 1- Template-guided, trans-perineal mapping biopsy (TTMB) for accurate tumor localization. 2- Multi-modal, multi-parametric imaging (MRI, ultrasound, and PET/CT) for patient selection and follow-up. 3- Novel dual-source based focal LDR-PB for improved targeting of the tumor. Cancer maps created from multi-modal, multi-parametric imaging will ultimately be used to guide or replace TTMB for patient selection, treatment planning and follow-up. We expect the proposed approach to provide a treatment alternative with fewer adverse effects for approximately 15-20% of men with high-risk PCa.