Random assignment between SBRT and conventionally fractionated boost following HDR brachytherapy for prostate cancer.

Many treatment options exist for prostate cancer. One common treatment approach is to combine high-dose rate (HDR) brachytherapy (temporary insertion of radiation into the prostate) and external beam radiation. External beam radiation typically requires daily radiation treatment for three to five weeks. Improvements to radiation planning and delivery has allowed stereotactic body radiation therapy (SBRT) to be implemented in many types of cancer. SBRT has been implemented as a standard treatment option after HDR brachytherapy in response to the COVID pandemic. We are seeking to evaluate whether it is feasible to randomly assign men between SBRT (which will be five treatments of radiation or conventional radiation (3-5 weeks of daily treatment) following HDR brachytherapy

Inclusion Criteria:

• Age 18 or older
• Informed consent for treatment and study participation completed
• Pathologically proven diagnosis of prostate adenocarcinoma
• ECOG Performance Status 0-2
• No prior history of pelvic radiotherapy, brachytherapy, cryosurgery, HIFU, TURP or radical prostatectomy

Exclusion Criteria:

• Presence of nodal or distant metastasis on staging MRI or CT Abdomen/Pelvis and Bone scan within 90 days of enrolment (CT/MRI/Bone Scan are only required if the clinical risk of metastatic disease is sufficient to warrant these scans)
• Plan for adjuvant chemotherapy post-radiotherapy
• Serious medical comorbidities or other contraindications to HDR brachytherapy
• Presence of inflammatory bowel disease
• Presence of connective tissue disorder seen as a contraindication to radiotherapy
• Medically unfit for general/spinal anesthesia
• Unable or unwilling to complete questionnaires