External Beam Radiotherapy for Prostate Cancer: Current Position and Trends

Abstract

External beam radiotherapy (EBRT) for the treatment of loco-regional prostate cancer yields similar survival rates to radical prostatectomy (10-year survival: 90-95%, 60-70% and 50-60% in T1, T2 and T3-stages, respectively). Post-operative radiotherapy in high-risk prostate cancer may improve the local and distant disease-free survival of patients. Using the recently developed technology of the 3D-conformal RT and of the intensity-modulated RT (IMRT), the focalized administration of a higher radiation dose is allowed keeping exposure of surrounding normal tissues to low levels. Cytoprotection with amifostine administration before EBRT fractions may reduce the incidence of early and late radiation sequel from the bladder and rectum. The developments in radiobiology suggest that large radiotherapy fractions may be more efficacious than standard radiotherapy, so that hypofractionation of radiotherapy may further improve local control rates. The use of interstitial high-dose rate implants to boost the prostate after an initial course of EBRT has been applied successfully in various institutes, with further improvement of the results obtained with EBRT. Chemotherapeutic agents, such as docetaxel and liposomal doxorubicin, as well as novel biological agents introduced into clinical practice (i.e. anti-erbB, anti-angiogenic and apoptosis-modulating agents) have shown significant radiosensitizing activity and deserve clinical evaluation in conjunction with radiotherapy.