Radiation Therapy for Prostate Cancer

This trial explores the optimal use of radiation therapy for treating prostate cancer while managing side effects. It compares two treatments: one combines brachytherapy (a type of internal radiation) with SBRT (a focused radiation treatment), and the other uses SBRT alone. Men with non-metastatic prostate cancer, deemed high-risk by their doctors, may qualify for this trial. Participants must be suitable for both types of radiation treatments as determined by their doctors. As a Phase 2 trial, this research measures the treatment's effectiveness in an initial, smaller group of participants.

Research has shown that stereotactic body radiation therapy (SBRT) is generally safe for treating prostate cancer. Studies indicate that serious side effects are rare, with fewer than 5% of patients experiencing severe issues. Over time, many patients treated with SBRT have not had their cancer return and remain healthy, though some may experience urinary problems a few years after treatment.

Brachytherapy, another type of radiation treatment where tiny radioactive seeds are placed inside or near the tumor, is also used for prostate cancer. Like SBRT, it is effective and usually well-tolerated by patients. Combining both treatments aims to increase effectiveness while keeping side effects low.

Researchers are excited about these prostate cancer treatments because they explore innovative uses of radiation therapy. Brachytherapy, or internal radiation, delivers radiation directly to the tumor, minimizing damage to surrounding healthy tissues. The combination of HDR Brachytherapy Boost with SBRT (stereotactic body radiation therapy) in Arm A is unique because it potentially offers a more targeted and intense treatment regimen compared to traditional methods, which often involve external beam radiation over several weeks. In Arm B, SBRT alone is being tested for its ability to deliver high doses of radiation in fewer sessions, which could mean a shorter treatment time with similar or improved outcomes. These approaches aim to enhance precision and effectiveness while reducing treatment duration and side effects.

Research has shown that SBRT, a type of precise radiation therapy, effectively treats prostate cancer. One important study found that 98.6% of men were cured after five years. After ten years, men who received SBRT maintained high survival rates and experienced few side effects. Another study found that about 95% of patients remained cancer-free after more than six years. In this trial, participants may receive SBRT alone, as in Arm B, or a combination of HDR Brachytherapy Boost and SBRT, as in Arm A. Overall, these findings suggest that SBRT is a safe and effective way to manage prostate cancer.²³⁶⁷⁸