The
objective of this study was to report our experience with
stereotactic radiosurgery performed with the Gamma Knife
(GK) in the treatment of patients with brain metastases and
to compare survival for those treated with radiosurgery
alone with survival for those treated with radiosurgery and
whole-brain radiotherapy. Prospectively collected
demographic and clinical characteristics and treatment and
survival data on 237
patients with intracranial metastases who underwent
radiosurgery with the GK between 2003 and 2007 were
reviewed. Kaplan-Meier and Cox proportional hazards
regression analyses were used to compare survival by
demographic and clinical characteristics and treatment.
Results
The mean
age of the patient population was 56 years. The most common
tumor histologies were non–small-cell lung carcinoma (34.2%)
and breast cancer (13.9%). The median overall survival time
was 8.5 months from the time of treatment. The
median survival
times for patients with one, two/three, and four or more
brain metastases were 8.5, 9.4, and 6.7 months,
respectively. Patients aged 65 years or greater and those
aged less than 65 years had median survival times of 7.8 and
9 months, respectively (p = 0.008). The Karnofsky
Performance Score (KPS) at the time of treatment was a
significant predictor of survival: those patients with a KPS
of 70 or less had a median survival of 2.9 months compared
with 10.3 months (p = 0.034) for those with a KPS of 80 or
greater. There was no statistically significant difference
in survival between patients treated with radiosurgery alone
and those treated with radiosurgery plus whole-brain
radiotherapy.
Conclusions
Radiosurgery with the GK is an efficacious treatment
modality for brain metastases. A KPS greater than 70,
histology of breast cancer, smaller tumor volume, and age
less than 65 years were associated with a longer median
survival in our study.
