Clinical Study Of Fraction Stereotactic Radiotherapy In Patients Of Brain Metastases

Objective: To evaluate the efficacy of fraction stereotactic radiotherapy (FSRT) in the treatment of patients with brain metastases, and to assess prognostic factors that correlated with survival.Materials and methods: 55 consecutive patients who presented with brain metastases underwent FSRT. Lesion primaries were non-small-cell lung (n=46), renal (n=1), breast (n=2), colon (n=1), other (n=2), and unknown primary (n =3). Some patients underwent whole brain radiotherapy to a dose of 30 Gy or 40 Gy. All patients underwent linac-based FSRT delivered in 2-18 fractions at 3-8Gy/f using a relocatable stereotactic frame. All patients were followed until death or for a median of 30 months after FSRT. Kaplan-Meier actuarial survival curves for all prognostic factors were calculated. Survival curves of subsets were compared by log-rank test. Application of the Cox model was utilized to identify any correlation between prognostic factors and survival.Results: The actuarial local control rates for all of the lesions were 92. 8%, the median overall survival time was 10 months after FSRT. On the basis of univariate analysis state of the primary disease (P = 0.0043), kps≥70(P= 0.0000), extracranial metastases (P= 0.0229), Score index for radiosurgy(SIR) class(P = 0.0064) and Radiation Therapy Oncology Group recursive partitioning analysis (RPA) class (P =0.0000) were associated with survival. Adjuvant WBRT,age, sex, number of metastases were not associated with survival. Multivariate analysis showed kps≥70 (P=0.000) and state of the primary disease (P =0. 003) to be independent predictors for overall survival.