Patent ID: 7982200

Claim:
An apparatus for ensuring adequate biological effectiveness at a treatment site of a patient, the apparatus comprising: a first component to determine a variability of relative biological effectiveness (RBE) at one or more of: a pre-plateau area of a spread-out Bragg peak (SOBP) of the treatment site, a proximal area of the SOBP of the treatment site, at a distal area of the SOBP of the treatment site, or a declining distal edge area of the SOBP of the treatment site, wherein RBE is a ratio of a dose of reference radiation to a hadron dose required to achieve a same biological effect; a second component to calculate a first RBE value at a pre-plateau area of a SOBP of the treatment site, a second RBE value at a proximal area of the SOBP, a third RBE value at a distal area of the SOBP, and a fourth RBE value at a declining distal edge area of the SOBP; a third component to adjust an intensity and energy of a proton beam at the pre-plateau area of the SOBP based on the first RBE value to provide a first dose distribution; a fourth component to adjust an intensity and energy of the proton beam at the proximal area of the SOBP based on the second RBE value to provide a second dose distribution; a fifth component to adjust an intensity and energy of the proton beam at the distal area of the SOBP based on the third RBE value to provide a third dose distribution; and a sixth component to adjust an intensity and energy of the proton beam at a declining distal edge area of the SOBP based on the fourth RBE value to provide a fourth dose distribution, wherein the first, second, third and fourth dose distributions superimpose to provide a desired radiation dose at the treatment site.