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Updated: Sep 17, 2025
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
Comparative Outcomes of Standard Radiation Therapy and 5-Fraction Adaptive Stereotactic Radiation Therapy in Newly
Michael Dohopolski1, Luiza Giuliani Schmitt1, Jill de Vis1
1Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas.
Purpose:
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults, with poor survival despite advancements in treatment. Adaptive stereotactic radiation therapy (RT) using a magnetic resonance imaging linear accelerator is an emerging approach for patients with newly diagnosed GBM eligible for conventional fractionation. We hypothesize that adaptive stereotactic RT can provide comparable outcomes with conventional fractionation while reducing treatment burden.
Methods And Materials:
We retrospectively reviewed 96 adults with newly diagnosed GBM treated at our institution between 2018 and 2024. Inclusion criteria included the age of 18 years, confirmed GBM diagnosis, and completed treatment. Patients with prior brain irradiation or incomplete treatment were excluded. Propensity score matching was performed to balance demographics, tumor characteristics, and treatment protocols across 5-fraction, 15-fraction, and 30-fraction groups. Statistical analyses included the Fisher exact test, Mann-Whitney U test, Cox proportional hazards models, and Kaplan-Meier survival curves.
Results:
After propensity score matching, 17 pairs were matched for 5 versus 30 fractions and 14 pairs for 5 versus 15 fractions. Median overall survival was 21.1 versus 18.2 months (5 vs 15 fractions, P = .77) and 11.7 versus 14.6 months (5 vs 30 fractions, P = .5). Median progression-free survival was 9.0 versus 7.9 months (5 vs 15 fractions, P = .89) and 8.9 versus 9.7 months (5 vs 30 fractions, P = .97). Local failure and grade 3 toxicity rates were similar across groups. O6-methylguanine-DNA-methyltransferase unmethylated status, higher Eastern Cooperative Oncology Group scores, and age 60 years were associated with worse progression-free survival and overall survival. Median travel distances were lower in the 5-fraction group, with a median of 220 miles compared with 877.5 (15 fractions) and 1638 miles (30 fractions). Adaptive RT allowed for real-time tumor monitoring but volumetric changes did not correlate with clinical outcomes.
Conclusions:
Adaptive 5-fraction RT demonstrates comparable survival outcomes with conventional fractionation while reducing treatment-related travel burden. Further prospective studies are needed to validate its role in GBM management.
