Stereotactic radiosurgery for brain metastases: results and prognostic factors

This study was conducted to determine prognostic factors for tumor response and patient survival after stereotactic radiosurgery (SRS) for brain metastasis. Eighty-four patients with brain metastasis underwent SRS at a single institution. After fixation of the head with a stereotactic frame, computed tomography treatment planning was performed. The metastatic lesion was treated with multiple arcs to a median dose of 19 Gy. Forty-seven patients (56%) had a solitary brain lesion. Fifty-nine patients (70%) had evidence of extracranial disease at the time of SRS. The median survival duration from SRS was 7 months. Sixty-three percent of the patients had an objective radiographic response to SRS, which in turn was associated with superior central nervous system control. Age, collimator size, number of arcs, tumor location, and histology did not influence objective response rates. Patients who had a solitary lesion or who received treatment within 2 weeks after diagnosis were more likely to have an objective response than were those who did not (P < 0.05). Progressive brain disease accounted for 37% of the deaths. Nineteen patients (23%) had an in-field relapse. Four severe complications were attributed to SRS. This study confirms the role of SRS as an acceptable treatment option for patients with solitary or limited brain metastases. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 157-162 (2000).