External beam radiotherapy for prostate cancer.

External beam radiotherapy (EBRT) constitutes an important management option for prostate cancer (PCa). Radiation doses >or=74 Gy are warranted. Dose escalation of EBRT using three-dimensional-conformal radiotherapy (RT) or intensity-modulated RT improves the therapeutic index by minimizing normal tissue complication probability and increasing tumor control probability. Although higher doses are associated with better biochemical disease-free survival, no impact on local recurrence or overall survival has been demonstrated. Hypofractionation for PCa may be an attractive therapeutic option, but toxicity data need to be confirmed in randomized phase III trials. Advances in RT technology, such as volumetric modulated arc therapy and image-guided RT, could facilitate the introduction of dose escalation and hypofractionation into clinical practice. Particle beam irradiation and more specific carbon ion RT are also very promising new techniques that are under investigation. Ultimately, these techniques may lead to focal dose escalation by selective boosting of dominant intraprostatic lesions, which is currently under investigation as a solution to overcome increased toxicity of homogenous dose escalation. This review will give a comprehensive overview of all the recent advances in these new radiation therapy techniques.