In 1970, a policy for the treatment of Stage IIIA Hodgkin's disease patients at the University of Minnesota, which included complete staging procedures and extended field or total nodal irradiation (TNI), was introduced. Evaluation of the results 4 years later indicated that certain patients, especially those with large mediastinal masses and/or hilar disease, or who were spleen positive, were having higher recurrence rates than patients without these characteristics. In 1974, a new approach to treatment for patients with large mediastinal masses or spleen positive disease was instituted which involved treating the whole lung or hemi lung in patients with large mediastinal masses and/or hilar disease, and the liver in patients who had positive spleens. The results of this treatment modification are reported in this study. Long term follow-up reveals that this approach has led to a recurrence free survival and overall survival similar to that noted in patients treated with combined modality treatment without the obvious risk of subsequent leukemia related to combination chemotherapy and radiotherapy. In addition, the complications of the treatment are tolerable and do not demonstrate an increase over patients not treated in this manner. Radical radiation therapy is recommended as a treatment of choice for Stage IA, IIA, and IIIA patients with or without splenic involvement, and with or without hilar disease and/or large mediastinal masses with appropriate radiation field modification to adjust for disease extent.