Impact of COVID on National Practice Patterns of Adjuvant Radiation Therapy Completion in Treatment of Glioblastoma.

OBJECTIVE: External beam radiation therapy (EBRT) remains the standard adjuvant treatment following maximally safe resection of glioblastoma multiforme (GBM). Hypofractionated radiotherapy (HFRT) offers comparable oncologic outcomes to standard fractionated radiotherapy (SFRT) while reducing overall treatment duration. The COVID-19 pandemic accelerated adoption of shorter regimens, yet its impact on national practice patterns and treatment completion has not been fully characterized. METHODS: Using the National Cancer Database, GBM patients receiving adjuvant radiotherapy from 2018 to 2022 were identified. SFRT was defined as 1.8 to 2.0 Gy per fraction to 60 to 66 Gy, and HFRT as 2.66 to 2.70 Gy per fraction to 40.05 to 40.5 Gy. Patients were grouped into pre-COVID (2018 to 2019), COVID (2020), and post-COVID (2021 to 2022) cohorts. Rates of HFRT utilization and radiotherapy completion were compared using a χ2 test. RESULTS: Among 43,696 patients, HFRT use increased from 10.1% pre-COVID to 11.9% post-COVID. HFRT demonstrated significantly higher treatment completion rates across all periods (79.3% to 82%) compared with SFRT (33.7% to 37.6%). Overall radiotherapy completion increased from 38.9% to 43.6% across the study period (P<0.0001). Most patients who completed radiotherapy also received chemotherapy (86.5%), were treated at academic centers (52.7%), and had a Charlson/Deyo comorbidity score of 0 (73.8%). CONCLUSION: Increased HFRT adoption during and after the pandemic was associated with improved treatment adherence, likely reflecting reduced logistical burden and shorter treatment duration. These findings support HFRT as an efficient, patient-centered radiotherapy approach for GBM, particularly in settings where minimizing treatment interruptions is critical. Further research is needed to evaluate long-term outcomes and potential impacts on treatment disparities.