Conformal radiotherapy for prostate cancer.

This review presents the contribution conformal treatment has made to the external beam treatment of prostate cancer drawing on 10 years of experience with three-dimensional conformal radiation treatment in 1500 patients with prostate cancer at our institution. Major contributions from other institutions and the Radiation Therapy Oncology Group (RTOG) clinical trials group are also noted. Patient immobilization, computed tomography (CT) scan identification of the target in three dimensions and beams-eye-view conformal treatment portals are critical to the process. Higher doses of radiation are associated with a marked increase in cure rates as the dose-response curve is extremely steep. The advantage given by the high dose depending on prognostic group ranges from 14% to 35% in 5-year cures. Conformal techniques protect normal tissues so that late complications are rare and in fact fewer than those observed with standard radiation technique at standard radiation doses. Educational efforts are underway in the USA to assist practising radiation oncologists to deliver the required radiation doses of 75-80 Gy safely. Conformal therapy cures more prostate cancers causing fewer complications than standard treatment technique and standard dose. It must therefore be disseminated into the practice of radiation oncology worldwide.