Increased Subventricular Zone Radiation Dose Correlates With Survival in Glioblastoma Patients After Gross Total Resection

Journal Article · Mon Jul 15 04:00:00 EDT 2013 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2013.02.014· OSTI ID:22224518

Chen, Linda ^[1]; Guerrero-Cazares, Hugo ^[1]; Ye, Xiaobu ^[2]; Ford, Eric ^[3]; McNutt, Todd; Kleinberg, Lawrence ^[4]; Lim, Michael; Chaichana, Kaisorn ^[1]; Redmond, Kristin ^[4]

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1. Department of Neurosurgery, The Johns Hopkins University, Baltimore, Maryland (United States)
2. Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, Maryland (United States)
3. Department of Radiation Oncology, University of Washington, Seattle, Washington (United States)
4. Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University, Baltimore, Maryland (United States)

Purpose: Neural progenitor cells in the subventricular zone (SVZ) have a controversial role in glioblastoma multiforme (GBM) as potential tumor-initiating cells. The purpose of this study was to examine the relationship between radiation dose to the SVZ and survival in GBM patients. Methods and Materials: The study included 116 patients with primary GBM treated at the Johns Hopkins Hospital between 2006 and 2009. All patients underwent surgical resection followed by adjuvant radiation therapy with intensity modulated radiation therapy (60 Gy/30 fractions) and concomitant temozolomide. Ipsilateral, contralateral, and bilateral SVZs were contoured on treatment plans by use of coregistered magnetic resonance imaging and computed tomography. Multivariate Cox regression was used to examine the relationship between mean SVZ dose and progression-free survival (PFS), as well as overall survival (OS). Age, Karnofsky Performance Status score, and extent of resection were used as covariates. The median age was 58 years (range, 29-80 years). Results: Of the patients, 12% underwent biopsy, 53% had subtotal resection (STR), and 35% had gross total resection (GTR). The Karnofsky Performance Status score was less than 90 in 54 patients and was 90 or greater in 62 patients. The median ipsilateral, contralateral, and bilateral mean SVZ doses were 48.7 Gy, 34.4 Gy, and 41.5 Gy, respectively. Among patients who underwent GTR, a mean ipsilateral SVZ dose of 40 Gy or greater was associated with a significantly improved PFS compared with patients who received less than 40 Gy (15.1 months vs 10.3 months; P=.028; hazard ratio, 0.385 [95% confidence interval, 0.165-0.901]) but not in patients undergoing STR or biopsy. The subgroup of GTR patients who received an ipsilateral dose of 40 Gy or greater also had a significantly improved OS (17.5 months vs 15.6 months; P=.027; hazard ratio, 0.385 [95% confidence interval, 0.165-0.895]). No association was found between SVZ radiation dose and PFS and OS among patients who underwent STR or biopsy. Conclusion: A mean radiation dose of 40 Gy or greater to the ipsilateral SVZ was associated with a significantly improved PFS and OS in patients with GBM after GTR.

• OSTI ID: 22224518
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 86; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BIOPSY
COMPUTERIZED TOMOGRAPHY
GLIOMAS
HEALTH HAZARDS
HOSPITALS
MULTIVARIATE ANALYSIS
NMR IMAGING
PATIENTS
PERFORMANCE
RADIATION DOSES
RADIOTHERAPY
SURGERY