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Gamma knife radiosurgery for brain metastasis of nonsmall cell lung cancer: Is there a difference in outcome between morning and afternoon treatment?†
Article first published online: 9 SEP 2010
Copyright © 2010 American Cancer Society
Volume 117, Issue 2, pages 414–420, 15 January 2011
How to Cite
Rahn, D. A., Ray, D. K., Schlesinger, D. J., Steiner, L., Sheehan, J. P., O'Quigley, J. M. and Rich, T. (2011), Gamma knife radiosurgery for brain metastasis of nonsmall cell lung cancer: Is there a difference in outcome between morning and afternoon treatment?. Cancer, 117: 414–420. doi: 10.1002/cncr.25423
Presented at the 2009 American Society for Radiation Oncology Annual Meeting (poster session).
- Issue published online: 5 JAN 2011
- Article first published online: 9 SEP 2010
- Manuscript Accepted: 8 APR 2010
- Manuscript Revised: 7 APR 2010
- Manuscript Received: 3 FEB 2010
- nonsmall cell lung cancer;
- brain metastasis;
- gamma knife radiosurgery;
- treatment time
Circadian cell-cycle progression causes fluctuating radiosensitivity in many tissues, which could affect clinical outcomes. The purpose of this study was to determine whether outcomes of single-session gamma knife radiosurgery (GKRS) for metastatic nonsmall cell lung cancer (NSCLC) differ based on treatment time.
Fifty-eight patients received GKRS between 10:00 am and 12:30 pm and 39 patients received GKRS between 12:30 pm and 3:00 pm. The mean peripheral dose was 18.6 Gy. The mean tumor size was 7.3 cm3. Magnetic resonance imaging was used to score local control at 3 months. Cause of death (COD) was categorized as central nervous system (CNS)-related or systemic.
Demographic and disease characteristics of the 2 groups were similar. Local control at 3 months was achieved in 97% (35/36) of patients who underwent GKRS early in the day versus 67% (8/12) of patients who underwent GKRS later in the day (chi-square, P = .014). Early GKRS was associated with better survival (median 9.5 months) than late GKRS (median 5 months) (Kaplan-Meier log-rank test, P = .025). Factors contributing to better survival in a Cox regression model included early treatment time (P = .004) and recursive partition analysis class (P < .001). Cause of death in the early treatment group was CNS-related in 6% (3/47) of patients versus 24% (8/34) of patients in the late treatment group (chi-square test, P = .026).
GKRS for metastatic NSCLC had better local control, better survival, and a lower rate of CNS-related cause of death when given earlier in the day versus later in the day. These retrospective data should encourage future study in brain radiosurgery and non-CNS stereotactic body radiotherapy series. Cancer 2011. © 2010 American Cancer Society.