An Endorectal Balloon is a small, disposable medical device that is made of soft, pliable material with a small balloon sitting on the end of a thin tube. The balloon is inserted in the rectum and inflated to stabilize the prostate during verification imaging and radiation therapy treatments.
Because the prostate sits in the middle of the pelvis it can be subject to motion caused by breathing, movement in your bowel or your bladder. Even modern radiation systems cannot fully compensate for this likely motion in real time. Therefore, the radiation zone is expanded beyond the actual tumor to ensure it is fully covered by the radiation beams even when there is motion, thus increasing the risk that healthy tissue also gets irradiated. Due to their proximity to the prostate, the rectum and anus are two anatomical structures at increased risk of receiving high dose radiation when they should not.
An endorectal balloon, has been shown to effectively stabilize the prostate, meaning it reduces prostate motion in any direction. In addition, the balloon consistently pushes large parts of the rectum and anus away from the high dose radiation zone, therefore protecting healthy tissue and helping to avoid acute and long-term radiation toxicity.