Intensity-Modulated Radiotherapy (IMRT) of Localized Prostate Cancer

PURPOSE: The present status of intensity-modulated radiation therapy (IMRT) for treatment of localized prostate cancer is discussed. METHODS: The technological basis of IMRT and the rationale for the use in treatment of prostate cancer are described. Clinical results from the literature are presented and treatment strategies for further reduction of safety margins are outlined. RESULTS AND DISCUSSION: Multiple planning studies demonstrated the dosimetric advantage of IMRT compared to three-dimensional conformal radiotherapy. Though randomized studies are missing, retrospective studies indicate that improved dose distributions of IMRT transfer into improved rates of local control and/or lower rates of rectal toxicity. However, with standard safety margins the benefit of IMRT seems to be limited. Image guidance is considered to be essential to reduce errors of patient setup and internal motion of the prostate.