Abstract
ObjectivesStandard 6-week and hypofractionated 3-week courses of adjuvant radiation therapy (RT) are both options for older patients with glioblastoma (GBM), but deciding the optimal regimen can be challenging. This analysis explores clinical factors associated with selection of RT course, completion of RT, and outcomes following RT.Materials and MethodsThis IRB-approved retrospective analysis identified patients ≥70 years old with GBM who initiated adjuvant RT at our institution between 2004 and 2016. We identified factors associated with standard or hypofractionated RT using the Cochran-Armitage trend test, estimated time-to-event endpoints using the Kaplan-Meier method, and found predictors of overall survival (OS) using Cox proportional hazards models.ResultsSixty-two patients with a median age of 74 (range 70–90) initiated adjuvant RT, with 43 (69%) receiving standard RT and 19 (31%) receiving hypofractionated RT. Selection of short-course RT was associated with older age (p = 0.04) and poor KPS (p = 0.03). Eight (13%) patients did not complete RT, primarily for hospice care due to worsening symptoms. After a median follow-up of 37 months, median OS was 12.3 months (95% CI 9.0–15.1). Increased age (p < 0.05), poor KPS (p < 0.0001), lack of MGMT methylation (p < 0.05), and lack of RT completion (p < 0.0001) were associated with worse OS on multivariate analysis. In this small cohort, GTV size and receipt of standard or hypofractionated RT were not associated with OS.ConclusionsIn this cohort of older patients with GBM, age and KPS was associated with selection of short-course or standard RT. These regimens had similar OS, though a subset of patients experienced worsening symptoms during RT and discontinued treatment. Further investigation into predictors of RT completion and survival may help guide adjuvant therapies and supportive care for older patients.
Highlights
Glioblastoma (GBM) is a malignancy of older adults
Following institutional review board approval, we identified patients with GBM who were ≥70 years old at time of pathologic diagnosis and initiated adjuvant radiation therapy (RT) in our radiation oncology department between 2004 and 2016
Temozolomide was administered to all patients where possible and dosed per the Stupp trial, and bevacizumab was administered at the discretion of the treating oncologist [2, 20, 21]
Summary
Glioblastoma (GBM) is a malignancy of older adults. The median age at diagnosis is 65 years old, and the incidence increases with age, peaking in the 75–84 years old age group [1]. The Stupp trial established the current standard treatment of maximal safe resection followed by adjuvant radiation therapy (RT) for 6 weeks with concurrent and adjuvant temozolomide [2]. This trial excluded patients >70 years old, and as age is both a negative prognostic factor and predictor of response to RT, other randomized studies have investigated radiation or temozolomide alone for older adults [3,4,5]. The Canadian trial found that in patients ≥60 years old, 40 Gy in 15 fractions was non-inferior to 60 Gy in 30 fractions, with median survival of 5.1 and 5.6 months, respectively [6]. A randomized study of patients ≥65 years old found that addition of temozolomide to the 40 Gy regimen did improve survival from 7.6 to 9.3 months [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
