Treatment > Radiosurgery

Meeting Abstract

Gamma knife radiosurgery (GKS) for metastatic tumors to brain

Praveen K Reddy, Gary V Burton, Richard Mansour, Glenn M Mills, Ajay Jawahar, Prasad Vannemreddy, Anil Nanda

Louisiana State University Health Science Center, Shreveport, LA

Objective. To evaluate the treatment results of GKS for metastatic tumors to brain.

Methods. The data on patients (pts) with metastatic brain tumors receiving GKS was obtained from our GKS database.
All variables including age, gender, location of primary tumor, number of brain lesions, prior brain radiation (XRT), tumor volume, dose of GKS, tumor response and survival were coded and entered into multivariate analysis.
The results are analyzed with respect to the response of the brain lesion and patient survival.

Results. There were 56 pts with metastatic brain tumors (36 males and 20 females, age range 36-77 years, mean age = 56).
Twenty-two pts had single and 34 had multiple lesions.
Tumor volume varied between 1-33 cc. (mean 8.3).
Primary tumor site was lung in 30 (53.6%) pts, melanoma in 7, breast in 7, colon in 4 and other in 8 pts.
Twenty-three pts received prior XRT.
All pts received a single GKS with dose ranging from 11-21 Grey (M=15.9).
There was no toxicity observed with GKS.
Follow up ranged from 6-77 weeks and the response outcome was available in 51 patients.
Treatment response was evaluated by interval MRI scans beginning at 6 wks post GKS.
Complete response of the brain lesion was seen in 8 (14%) pts, partial response in 20 (36%), stable disease in 10 (18%), disease progression in 13 (23%) and 5 (9%) pts were inevaluable for response.
Pt survival at 6, 12 and 18 months was 37 (66%), 16 (29%) and 3 (5%) respectively.
A multivariate analysis for prognostic indicators of GKS response did not reveal any variable with significant influence on the treatment results.
Survival, however, had significant correlation with solitary metastasis (P<0.03) and good response to GKS (P<0.002), whereas site of primary, prior XRT and tumor volume had no significant influence.

Conclusion. GKS appears to be an effective non-invasive adjuvant treatment modality for metastatic lesions involving the brain.
Sixty-eight percent of pts demonstrated a good response with stabilization or reduction of tumor mass following treatment.
The overall impact of GKS on patient survival and quality of survival is difficult to define.
Further data analysis is expected to reveal factors predictive of GKS benefit in pts with secondary brain tumors.

© Copyright 2002 American Society of Clinical Oncology