RADIATION-THERAPY FOR LOCALIZED DISEASE

Background. Since 1910, a variety of radiation modalities, including radioactive isotopes, photons, and particle beams, have been used to treat prostatic cancer. Methods. This report focuses on external beam x-irradiation produced by medium energy linear accelerators. Between 1956 and 1990, 1119 patients have been treated with curative intent at Stanford University. Tumor doses of 70 Gy delivered at 10 Gy/wk have been safe and effective. Results. Fifteen-year survival rates ranging from 50%, equivalent to that of an age-matched cohort, for the least extensively localized tumors to 18% for the most extensive have been achieved. Survival is inversely proportional to clinical stage and histopathologic grade. Conclusion. Although external beam radiation therapy has been found to be safe and effective for the treatment of prostatic cancer, improvement in results of treatment of the more advanced tumors might be achieved by combining external beam and interstitial irradiation. This would achieve a higher radiation dose within the tumor. Alternatively, the treatment can be augmented with hyperthermia or other sensitizers in order to achieve a higher biological dose.