Patients are evaluated on a monthly basis for response. Patients with unchanged or undetectable prostate specific antigen levels are considered to have reached maximal hormonal response and three dimensional conformal external beam radiotherapy is instituted. In addition, patients with disease progression are considered to have reached maximal response, and three dimensional conformal external beam radiotherapy is instituted. Radiotherapy must be administered within 6 months after initiation of leuprolide and flutamide therapy.