Hypofractionated stereotactic radiotherapy as an alternative to radiosurgery for the treatment of patients with brain metastases

Purpose: Modeling studies have demonstrated a potential biologic advantage of fractionated stereotactic radiotherapy for malignant brain tumors as com pared to radiosurgery (SRS), even when only a few fractions are utilized. W e prospectively evaluated the feasibility, toxicity, efficacy and cost of h ypofractionated stereotactic radiotherapy (HSRT) in the treatment of select ed radiosurgery-eligible patients with brain metastases, Methods and Materials: Patients with a limited number of brain metastases n ot involving the brainstem or optic chiasm underwent linac-based HSRT deliv ered in 3 fractions using a relocatable stereotactic frame. Depth-helmet an d reference point measurements were recorded to address treatment accuracy. All patients underwent whole brain radiotherapy to a dose of 30 Gy, Toxici ty, response, and survival duration were recorded for each patient. Prognos tic factors were assessed by Cox regression analysis. Cost comparisons with a cohort of SRS treated patients were performed, Results: Thirty-two patients with 57 brain metastases were treated with HSR T. Twenty-three and 9 patients underwent HSRT for upfront and salvage treat ment, respectively. The median dose delivered was 27 Gy, given in 3 fractio ns of 9 Gy, From 3328 depth-helmet measurements, the absolute median setup deviation in AP, lateral, and vertical orientations was approximately 1.0 m m, No significant acute toxicity was seen, Late toxicities included seizure s in four patients, and radionecrosis in two patients, The median survival duration from treatment was 12 months. KPS (p = 0.039) and RTOG-RPA class ( p = 0.039) were identified as significant prognostic factors for survival. HSRT was $4119 less costly than SRS. Conclusion: HSRT, as delivered in this study, is more comfortable for patie nts and less costly than SRS in the treatment of selected patients with bra in metastases, Proper dose selection and radiobiologic/toxicity trade-offs with SRS await further study. (C) 2000 Elsevier Science Inc.