Implications of Identifying Additional Cerebral Metastases during Gamma Knife Radiosurgery

Abstract EN

Introduction.

Gamma Knife radiosurgery (GK-SRS) is commonly used to treat cerebral metastases.

Although additional intracranial metastases are often found on the day of GK-SRS, the significance of finding them is unknown.

Methods.

A retrospective review of 133 patients undergoing GK-SRS for cerebral metastases was performed.

The change in number of metastases detected between initial referral magnetic resonance imaging (MRI) and subsequent treatment MRI was quantified.

Multivariate and Kaplan-Meier analyses were employed to examine the significance of identifying additional lesions.

Results.

Additional lesions were identified in 41% of patients.

An increasing number of metastases on referral MRI (P=0.001) and the presence of progressive systemic disease (P=0.003) were predictive of identifying additional metastases.

Median survival was 6.9 months for patients with additional metastases, compared to 12.1 months for patients without additional metastases (hazard ratio 1.56, P=0.021).

Conclusions.

Identifying additional metastases on the day of GK-SRS may add important prognostic information.