How does Proton Therapy differ from standard X-ray beams?

Protons stop once they reach the tumor, reducing dose to tissues behind the prostate

While standard photon or X-ray beams pass entirely through the body, potentially depositing radiation in healthy tissues located on the other side of the prostate, proton therapy works differently. Protons can be calibrated to hit a specific depth and then stop completely once they reach the tumor. This physical characteristic allows for the reduction of the total radiation dose absorbed by healthy organs located behind the prostate, such as the rectum.