Stereotatic Radiosurgery for Brain Metastases：Prognostic Factors for Survival and Local Control

다국어 초록 (Multilingual Abstract)

Objective：Survival and the local control of brain metastases following gamma knife radiosurgery(GKRS) are analyzed and their prognostic factors are presented.

Methods：Survival analysis was performed upon 100 consecutive patients with 263 lesions treated during the period December 1997 to September 2001. Common primary sites were lung(49 patients), kidney(nine), colon(seven), breast(six) and unknown origin(six). Ages ranged from 19 to 79 years(mean 56) and the male to female ratio was 1.6：1. The mean tumor volume was 4.6cc(range 0.01-48.9), the mean marginal dose 17.1Gy(range 5-25), and the mean follow-up period 42 weeks(range 1-173). Magnetic resonance(MR) imaging was scheduled at 1 month, then every 2 months. Follow-up imaging was available in 73 patients and 68 patients expired during the follow-up.

Results：Overall median survival was 46 weeks. Six-month and 1-year survival rates were 65% and 42%, respectively. Tumor volume, Karnofsky performance scale(KPS), control of primary tumor and absence of extracranial metastasis were statistically significant prognostic factors(p<0.05) for survival by multivariate analysis. The 1-year actuarial local control rate was 65% and renal cell carcinoma showed poorer control than other tumors(p<0.05) by multivariate analysis.

Conclusion：It is suggested that GKRS is a safe, effective and convenient alternative to surgery with whole brain radiotherapy and is expected to be more widely used in the treatment of brain metastases.



Key words:Brain metastases;Gamma knife radiosurgery(GKRS);Survival;Local control;Prognostic factors.