Radiosurgical salvage therapy for patients presenting with recurrence of metastatic disease to the brain

OBJECTIVE: Radiosurgery has emerged as an important modality in the managem ent of metastatic disease to the brain. A number of groups have published r esults suggesting that high local control rates can be achieved, with impro vements in overall survival that rival the results of open surgical treatme nt. Typically, however, whole-brain radiotherapy has been used in the salva ge therapy of patients who have undergone previous craniotomy or radiosurge ry. We describe our experience with radiosurgical salvage in this group of patients. METHODS: From August 1994 to February 1999, 190 patients with brain metasta sis were treated with gamma unit radiosurgery at our institution. A subset of 45 patients, who underwent radiosurgical salvage for new tumors in a reg ion remote from an initially treated tumor, form the population base for th is study. The usual criteria for repeat treatment were recurrence with five or fewer discrete lesions outside of the previously treated radiosurgical volume and Karnofsky Performance Scale score of at least 70, Survival and f reedom from progression were measured from the time of radiosurgical treatm ent and were computed by the Kaplan-Meier product-limit method. Two or more curves were compared using the log-rank method. RESULTS: In this subgroup of patients, a total of 176 tumors were treated. The median time from first radiosurgical procedure to first salvage was 17. 4 weeks. Median survival from the second radiosurgical intervention was 28 weeks. Of the 45 study patients, 34 patients underwent a single salvage pro cedure, 10 patients underwent two salvage procedures, and 1 patient had thr ee salvage procedures. The actuarial freedom from progression for treated t umors at 52 weeks was 92.4%. Patients undergoing upfront whole-brain irradi ation were less likely to require salvage therapy (P = 0.008). There were 3 3 deaths after salvage radiosurgery during the reporting period. Central ne rvous system causes accounted for 13 deaths, whereas 19 deaths resulted fro m systemic disease. The cause of death in one patient could not be determin ed. No statistically significant advantage in overall survival could be dem onstrated in patients treated with whole-brain irradiation. CONCLUSION: Radiosurgical salvage represents a valuable means of treatment for central nervous system recurrence for patients who have undergone previ ous treatment for metastatic disease to the brain. Whole-brain irradiation may reduce the need for salvage therapy, but no advantage in overall surviv al could be demonstrated in this subgroup.