Linear-accelerator-based stereotactic irradiation for metastatic brain tumors

To assess the safety and availability of stereotactic radiotherapy (SRT) for metastatic brain tumors, we reviewed 54 consecutive cases with a total of 118 brain metastases treated with linear-accelerator-based stereotactic irradiation (STI). Nineteen patients with a total of 27 brain tumors that were larger than 3 cm or close to critical normal tissues were treated with SRT. The marginal dose of SRT was 15-21 Gy (median 21 Gy) in 3 fractions for 3 days. The median marginal dose of stereotactic radiosurgery (SRS) was 20 Gy. Effective rates of imaging studies were 72.7% and 94.4%, and those of clinical symptoms were 46.7% and 55.6% for SRT and SRS, respectively. One-year and two-year survival rates of SRT were 40.9% and 17.6%, respectively, and the median follow-up period was 6.4 months. The one-year survival rate of SRS was 32.7%, with a median follow-up of 4.6 months. Fourteen cases (7 cases each) had recurrent tumors at STI sites. Early complications were observed in one case of SRT and 8 cases of SRS, and late complications occurred in 3 cases of SRS. There were no significant differences among effective rates, survival rates, median follow-up times, recurrence rates, and complications between SRT and SRS. We concluded that SRT is a safe, effective therapy for large or eloquent area metastases. (author)