[Tridimensional conformal radiotherapy of cancer of the prostate].

3D-conformal-radiation therapy is now available according to progress in imaging and treatment planning. It gives three advantages: better coverage of clinical target volume, decrease of dose in organs at risk and in some cases possibility of escalating the dose in the clinical target volume. These three theoretical advantages are demonstrated for localized prostate adenocarcinomas. An increase of clinical and biological cure rate was demonstrated with 3D-CRT compared with conventional technique for the same dose. A decrease of acute and late complications was observed with 3D-CRT in historical comparisons and in randomized clinical trials. The most exciting point were the results of studies of escalating dose (+10 or 15%). There was a relationship between dose and clinical and biological cure rate. The french study of escalated dose showed a probability of clinical and biological cure rate at 36 months of 50% for doses between 66 and 70 Gy and 85% for doses between 74 and 80 Gy. In conclusion, 3D-CRT is becoming more and more important in the treatment of localized prostate carcinoma.