Dose fractionation and biological optimization in carcinoma of the prostate

Three-dimensional conformal radiation therapy (3-D CRT) or intensity-modulated radiation therapy (IMRT) have been increasingly used as an alternative to radical prostatectomy in patients with localized carcinoma of the prostate and in patients at high risk, in combination with hormonal therapy. To better understand the implications of dose-time and fractionation in prostate cancer, it is important to be familiar with some laboratory investigations dealing with the cell kinetics characteristics of this tumor. Biological and clinical considerations of dose fractionation, total dose of irradiation and local tumor control, elapsed overall treatment time and sequelae of irradiation are illustrated, based on an exhaustive review of the literature.