Brain Metastasis Velocity: A Novel Prognostic Metric Predictive of Overall Survival and Freedom From Whole-Brain Radiation Therapy After Distant Brain Failure Following Upfront Radiosurgery Alone

Journal Article · Mon May 01 00:00:00 EDT 2017 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2017.01.201· OSTI ID:22649916

Farris, Michael ^[1]; McTyre, Emory R.; Cramer, Christina K.; Hughes, Ryan; Randolph, David M.; Ayala-Peacock, Diandra N.; Bourland, J. Daniel ^[1]; Ruiz, Jimmy ^[2]; Watabe, Kounosuke ^[3]; Laxton, Adrian W.; Tatter, Stephen B. ^[4]; Zhou, Xiaobo ^[5]; Chan, Michael D. ^[1]

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1. Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)
2. Department of Medicine - Hematology & Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)
3. Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)
4. Department of Neurosurgery, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)
5. Center for Bioinformatics & Systems Biology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)

Purpose: Prior statistical models attempted to identify risk factors for time to distant brain failure (DBF) or time to salvage whole-brain radiation therapy (WBRT) to predict the benefit of early WBRT versus stereotactic radiosurgery (SRS) alone. We introduce a novel clinical metric, brain metastasis velocity (BMV), for predicting clinical outcomes after initial DBF following upfront SRS alone. Methods and Materials: BMV was defined as the cumulative number of new brain metastases that developed over time since first SRS in years. Patients were classified by BMV into low-, intermediate-, and high-risk groups, consisting of <4, 4 to 13, and >13 new metastases per year, respectively. Histology, number of metastases at the time of first SRS, and systemic disease status were assessed for effect on BMV. Results: Of 737 patients treated at our institution with upfront SRS without WBRT, 286 had ≥1 DBF event. A lower BMV predicted for improved overall survival (OS) following initial DBF (log-rank P<.0001). Median OS for the low, intermediate, and high BMV groups was 12.4 months (95% confidence interval [CI], 10.4-16.9 months), 8.2 months (95% CI, 5.0-9.7 months), and 4.3 months (95% CI, 2.6-6.7 months), respectively. Multivariate analysis showed that BMV remained the dominant predictor of OS, with a hazard ratio of 2.75 for the high BMV group (95% CI, 1.94-3.89; P<.0001) and a hazard ratio of 1.65 for the intermediate BMV group (95% CI, 1.18-2.30; P<.004). A lower BMV was associated with decreased rates of salvage WBRT (P=.02) and neurologic death (P=.008). Factors predictive for a higher BMV included ≥2 initial brain metastases (P=.004) and melanoma histology (P=.008). Conclusions: BMV is a novel metric associated with OS, neurologic death, and need for salvage WBRT after initial DBF following upfront SRS alone.

• OSTI ID: 22649916
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 98, Issue 1; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BRAIN
METRICS
MULTIVARIATE ANALYSIS
NEOPLASMS
RADIOTHERAPY
STATISTICAL MODELS
SURGERY
SURVIVAL TIME