26-27 / 3107
Relative Biological Effectiveness (RBE) - particles
RBE-weighted Dose (Gy (RBE)) = Absorbed Dose (Gy) x RBE
RBE =
D
(Co-60; 250kV)
D
(p-ions)
Biological effect
(cell inactivation)
RBE is the ratio of the dose of photons, e.g.,
60
Co-rays or linear accelerator X-
rays, relative to that of protons/ions required to produce a defined biologic
response