Hi @kco,
Conventional radiation (photon) uses a beam of x-rays that travel through the body in a straight line. It deposits its energy in the normal tissues around the targeted tumor. Proton Beam therapy uses pencil beam scanning to deliver concentrated radiation to the tumor while minimizing the exposure to the surrounding healthy tissue. You can read more about Proton Beam Therapy here: https://www.mayoclinic.org/tests-procedures/proton-therapy/about/pac-20384758

Proton therapy isn't widely available in the United States. Mayo has treated oral cancer with proton beam therapy since we opened in 2015.

Fellow members @puprluvr and @rgotto41 may be able to share more about their experiences. @kco, are you deciding which radiation treatment to have?