Proton Treatment Planning

Abstract

The differences between planning proton-beam therapy and photon-beam therapy derive from the differences in the physics of protons and photons, namely [1]:That protons have a finite and controllable (through choice of energy) penetration in depth with virtually no exit dose (Fig. 3.1).That the penetration of protons is strongly affected by the nature (e.g., density) of the tissues through which they pass, while photons are much less affected (density changes generally give rise to only small intensity changes, except for the lung). Therefore, heterogeneities are much more important in proton-beam therapy than in photon-beam therapy (Fig. 3.2).The apparatus for proton-beam delivery is different, and its details affect the dose distributions (Chap. 2).