Fractionated Stereotactic Radiotherapy For Brain Metastases

Purpose:To assess feasibility and outcomes after fractionated stereotactic radiotherapy(FSRT) for brain metastases larger than 3 centimeters.Patients and Methods:From September 1996 to July 2006,51 patients with brain metastases larger than 3 centimeters were treated by FSRT.Forty-seven patients were eligible for analysis,out of which,34 were male patients and 13 were female patients.Median age was 58(range from 31 to 87) years old.FSRT was employed as initial treatment for brain metastases in 26 patients,and as salvage therapy,in 21 patients.The largest diameters of brain metastases were from 3.1cm to 6.0cm(with median at 3.8cm).Planning target volume were from 2519 to 33799 mm~3(with median at 9418 mm~3).Median dose of FSRT fraction was 30(16-57) Gy/5(2-11). The delivery was performed with one isocenter in 48 patients,and two isocenters in 3 patients.Four to five noncoplanar arcs with each isocenter were employed to describe 70%-90%isodose curves normalized to the isocenters to surround the target areas.Result:Four patients were lost during follow-up.For the 47 patients we followd,46 died.Among them 21 patients died of brain metastases,17 patients died of extracranial progression,and the other 8 patients died of other reasons.The median survival time was 11(range from 0.5 to 88,95%CI:8.1-13.8) months.The mean survival time was 17.2(range from 0.5 to 88,95%CI:11.5-22.9) months.The overall survival rate was 38%at 1 year.The local control rate was 44%at 1 year. Conclusion:FSRT was safe and beneficial for selected patients with brain metastases larger than 3cm.