This is a single-arm feasibility study that is recruiting 40 patients with histologically-proven localized prostate cancer and MRI-defined lesion(s). Participants in this study will get MR-guided radiotherapy boost to MRI visible tumour before or after whole gland radiation. Participants will be followed-up as per standard of care schedule up to 5 years post-treatment.

Inclusion Criteria:

• Histologically-proven localized prostate cancer.
• Low, Intermediate, and High-risk prostate cancer (ideally limited to 1 risk factor)
• Low-risk: cT1-T2a, PSA <10, and Gleason score 6
• Intermediate-risk: cT2b-c, PSA 10-20, and/or Gleason score 7
• High-risk limited to 1 risk factor: >T2, PSA >20, or Gleason score >7
• Intra-prostatic tumour(s) demonstrated on mpMRI histologically confirmed limited to =/< 1/3 total prostate volume
• Planned for EBRT (+/- ADT)
• ECOG 0 or 1
• 18 years of age or older
• Ability to provide written informed consent to participate in the study

Exclusion Criteria:

• Prior radiotherapy to pelvis
• Radiological evidence of regional or distant metastases at the discretion of the treating physician.
• Active ulcerative colitis or Crohn's Disease, at discretion of treating physician
• Ataxia Telangectasia and SLE
• Contraindications to MRI; including patients with pacemakers/implantable cardiac defibrillator, cerebral aneurysm clips, shrapnel injury
• Severe claustrophobia