Percutaneous radiotherapy for low-risk prostate cancer: options for 2007.

Technical developments of radiotherapy (RT) over the recent years yielded in better conformation to the target volume thus increasing the therapeutic ratio and decreasing side effects. This paper discusses these options for low-risk prostate cancer. There has been evidence from randomized trials, that for low-risk PCA doses >70 Gy are significant better in case of biochemical disease-free survival (bNED). Image-guided radiotherapy (IGRT) has been proven in several studies for reduced safety margins around the prostate target volume. Intensity-modulated radiotherapy (IMRT) allow treatment with higher doses and 5-year results are reported from several studies. Data from several randomized trials about adjuvant RT after radical prostatectomy (RP) have been reported. In two phase-III trials a significant advantage of 20% bNED was demonstrated for doses between 76 and 79 Gy compared with 70 Gy. Using IGRT, the safety margin around the prostate can be reduced for about 30-50%. Doses of >80 Gy can be given safely to the prostate with IMRT and <5% grade-III/IV late side effects. Adjuvant RT for positive margins after RP has been of proven advantage. Three phase-III trials achieved a significant better bNED of 20% for 5 years. The effect of doses >70 Gy have been proven for low-risk PCA. IGRT resulted in reduced safety margins and a decrease of acute and late side effects. The addition of IMRT allowed higher doses to the prostate. Adjuvant RT after RP for positive margins achieved a significant better bNED.