Radiobiology of Prostate Cancer

The 1999 proposal of Brenner and Hall of an α/β value of 1.5 Gy for prostate tumors has rekindled the interest in the traditional radiobiological aspects of time, dose, and fractionation as effective means of modulating the therapeutic window in radiation therapy. It is well established that, depending on the fractionation sensitivity of normal and tumor tissues, one could depart from the usual fractionation pattern and devise schedules that lead to the same tumor results with less complications, or better tumor control with the same level of complications. Never­theless, radiobiology experience indicates that the success of any fractionation schedule depends on the temporal pattern of dose delivery. From this perspective, the present chapter aims to review the radiobiological aspects that may be relevant for the design of treatment schedules for prostate tumors.