From 1983 through 1986, the Southwest Oncology Group and Radiation Therapy Oncology Group conducted an inter group study designed to evaluate the effectiveness of surgical resection in those patients with solitary central nervous system (CNS) metastases. The study was initially designed as a prospective randomized trial. Because of difficulty accruing patients, the registration format was altered and the patients were placed on study according to physician preference. Ninety-seven patients were registered on study and 80 patients were eventually analyzed. Fifty-five patients underwent radiation therapy alone and 25 patients received surgery and radiation. Fifty-nine percent of those patients undergoing radiation therapy alone improved or stabilized while 79% of those patients undergoing surgery and radiation therapy improved or stabilized. Eventually. 22% of the surgically treated patients failed in the brain while 45% of the patients undergoing radiation therapy exhibited a CNS relapse. Survival was improved when corrected for other prognostic factors in those patients undergoing surgical resection. Although not a prospective randomized trial, this study does suggest an improvement in the survival of a select group of patients able to tolerate neurosurgical resection.