[Prostate cancer: what treatment techniques for which tumors? Ethical and methodological issues]

The identification of the optimal radiation technique in prostate cancer is based on the results of dosimetric and clinical studies, although there are almost no randomized studies comparing different radiation techniques. The feasibility of the techniques depends also on the technical and human resources of the radiation department, on the cost of the treatment from the points of view of the society, the patient and the radiation oncologist, and finally on the choice of the patient. The slow evolution of prostate cancer leads to consider the biochemical failure as the main judgment criteria in the majority of the studies. A proper urinary radio-induced toxicity evaluation implies a long follow-up. Intensity-modulated radiotherapy (IMRT) combined with image-guided radiotherapy (IGRT) is recommended in case of high dose (≥76Gy) to the prostate, pelvic lymph nodes irradiation and hypofractionation schedules. For low-risk tumors, the aim of the treatment is to preserve quality of life, while limiting costs. Stereotactic body radiotherapy shows promising results, although the follow-up is still limited and phase III trials are ongoing. Focal radiation techniques are in the step of feasibility. For intermediate and high-risk tumors, the objective of the treatment is to increase the locoregional control, while limiting the toxicity. IMRT combined with IGRT leads to either a well-validated dose escalation strategy for intermediate risk tumors, or to a strategy of moderate hypofractionated schedules, which cannot be yet considered as a standard treatment. These combined radiation techniques allow finally large lymph node target volume irradiation and dose escalation potentially in the dominant intraprostatic lesion. The feasibility of simultaneous integrated boost approaches is demonstrated.