Stereotactic Radiosurgery of the Postoperative Resection Cavity for Brain Metastases: Prospective Evaluation of Target Margin on Tumor Control

Journal Article · Mon Oct 01 04:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.12.009· OSTI ID:22149501

Choi, Clara Y.H.; Chang, Steven D. ^[1]; Gibbs, Iris C. ^[2]; Adler, John R.; Harsh, Griffith R.; Lieberson, Robert E. ^[1]

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1. Department of Neurosurgery, Stanford University Medical Center, Stanford, California (United States)
2. Department of Radiation Oncology, Stanford University Medical Center, Stanford, California (United States)

Purpose: Given the neurocognitive toxicity associated with whole-brain irradiation (WBRT), approaches to defer or avoid WBRT after surgical resection of brain metastases are desirable. Our initial experience with stereotactic radiosurgery (SRS) targeting the resection cavity showed promising results. We examined the outcomes of postoperative resection cavity SRS to determine the effect of adding a 2-mm margin around the resection cavity on local failure (LF) and toxicity. Patients and Methods: We retrospectively evaluated 120 cavities in 112 patients treated from 1998-2009. Factors associated with LF and distant brain failure (DF) were analyzed using competing risks analysis, with death as a competing risk. The overall survival (OS) rate was calculated by the Kaplan-Meier product-limit method; variables associated with OS were evaluated using the Cox proportional hazards and log rank tests. Results: The 12-month cumulative incidence rates of LF and DF, with death as a competing risk, were 9.5% and 54%, respectively. On univariate analysis, expansion of the cavity with a 2-mm margin was associated with decreased LF; the 12-month cumulative incidence rates of LF with and without margin were 3% and 16%, respectively (P=.042). The 12-month toxicity rates with and without margin were 3% and 8%, respectively (P=.27). On multivariate analysis, melanoma histology (P=.038) and number of brain metastases (P=.0097) were associated with higher DF. The median OS time was 17 months (range, 2-114 months), with a 12-month OS rate of 62%. Overall, WBRT was avoided in 72% of the patients. Conclusion: Adjuvant SRS targeting the resection cavity of brain metastases results in excellent local control and allows WBRT to be avoided in a majority of patients. A 2-mm margin around the resection cavity improved local control without increasing toxicity compared with our prior technique with no margin.

• OSTI ID: 22149501
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 84; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRAIN
CAVITIES
CONTROL
DEATH
EVALUATION
FAILURES
HEALTH HAZARDS
HISTOLOGY
IRRADIATION
MELANOMAS
METASTASES
MULTIVARIATE ANALYSIS
PATIENTS
RADIOTHERAPY
RISK ASSESSMENT
SURGERY
TOXICITY