RESUMEN
Objective To analyze the clinical efficacy of gamma-ray fractionated stereotactic radiotherapy (FSRT) in the treatment of intracranial metastatic polycystic tumors.Methods Forty cases with 61 metastatic polycystic tumors were selected from 189 patients with 373 intracranial metastatic tumors admitted to our hospital from 2013 to 2015.All cases received gamma-ray FSRT.The isodose line at 50％ was defined as the prescription dose.The prescription dose was ranged from 40 to 48 Gy/10-12f.The survival rate was calculated by Kaplan-Meier method.The single factor analysis was performed by Log-rank method.Results The median follow-up time was 21months (range:6-39 months).The median survival time was 15.3 months.The 6-month,1-and 2-year local control rate was 93％,82％ and 79％,respectively.The 1-and 2-year survival rate was 63％ and 30％.Single factor analysis demonstrated that the volume of cysts and the volume of lesions were not significantly correlated with local control rate (P=0.17 and 0.48).Conclusion Gamma-ray FSRT can be adopted to treat intracranial metastatic polycystic tumors,which yields similar clinical efficacy to metastatic solid tumors.It deserves wide application in clinical practice due to high local control rate and safety.