Does the time of treatment of Gamma Knife Radiosurgery for Non-Small Cell Lung Carcinoma Brain Metastases affect the Outcomes?Areeporn Chonhenchob1, Paul Elson21Cleveland, United States 2Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio Keywords: brain metastasis, gamma knife, lung cancer, technique, outcome
To assess the impact of the time of treatment of GKRS for non-small cell lung carcinoma (NSCLCa) on outcomes.
At treatment, 50% were male, median age was 61 years (35-92), and 45% of patients had good performance status (KPS 90-100).
A retrospective analysis was performed on 286 patients who underwent GKRS for metastatic brain tumors from NSCLCa at The Cleveland Clinic Gamma Knife Center between January 2005 and February 2011.
Histologies were adenocarcinoma (76%), squamous cell carcinoma (14%), and others (10%). Forty-nine% and 63% of patients had prior WBRT and chemotherapy, respectively. Twenty-two% of patients had extracranial metastases at the time of GKRS. Patients had a median of 2 brain lesions (1-10), with 46%, 23%, and 32% having 1,2, and >3 lesions respectively. Median maximum tumor size was 1.70 cm (0.04-36.1), and median total tumor size was 2.10 cm (0.04-37.20). 71% of patients were treated between 11:00 a.m.-2:55 p.m., 9% between 8:30-10:55 a.m. and 10% between 3:00-6:35 p.m. First follow-up MRI showed 69% of patients had a response to GK, 23% had stable disease, and 8% progressed. The median time from GK to first follow-up MRI was 2 months (0.5-9). Estimated 6 month, 1-year, 2-year, and median survival are 72% + 3%, 49% +3, 29% + 3%, and 11.9 months (95% C.I. 100-15.3), respectively. In univariate analysis, factors prognostic for overall survival were: performance status (p<.0001), presence of extracranial metastases (p=.0005), gender (p=.006), maximum tumor size (p=.003), tumor burden (p=.01), age (p=.01), histology (p=.02), the number of isocenters (p=.02) and the number of brain lesions (p=.07). Time of day did not impact overall survival (p=.39 for prior to 12:30 p.m. versus after 12:30, and p=.34 dividing time of day). In multivariable analysis, the number of isocenters was the only independent predictor of response.
This was a retrospective study.
The prognostic factors for lung cancer brain metastases outcomes are KPS, presence of extracranial metastases, gender, age, tumor size, histology, complexity of GKRS, and number of lesions.
This study demonstrates that there is no impact of time of treatment on outcomes in overall survival and local control. Project Roles:
A. Chonhenchob (), P. Elson ()