Early Experience With Biologically Effective Dose-Comparable Short-Course Whole Brain Radiation Therapy for Metastatic Intracranial Disease

Abstract

Objectives: For inpatients with metastatic intracranial disease burden exceeding established guidelines for stereotactic radiosurgery (SRS), the standard of care involves whole brain radiation therapy (WBRT), typically administered as a 2-week course of treatment with biologically effective dose (BED) of 60 Gy. However, shorter course WBRT provides theoretical advantages in quality of life and decreasing systemic therapy delay. This retrospective study evaluates our early experience with BED-comparable short-course WBRT (23 Gy in 5 fractions; BED=58.3 Gy) for metastatic intracranial disease.

Methods: Over a recent 2-month timeframe, 3 inpatients with intracranial disease burden exceeding SRS guidelines were administered BED-comparable short-course WBRT. Due to the high intracranial disease burden, 23 Gy was chosen over 20 Gy for 5-fraction WBRT due to the desire to optimally mimic the durability of the classic 30 Gy in 10 fraction treatment regimen.

Results: The mean age at treatment was 65.7 years, the mean Karnofsky Performance Status (KPS) was 60, and the mean number of intracranial metastases was 20.3. The mean duration between inpatient Radiation Oncology consultation and the start of WBRT (following CT radiation therapy simulation) was 6.7 days. All patients completed WBRT no later than 2 weeks from the initial inpatient consultation.

Conclusions: For inpatients with intracranial metastatic disease burden exceeding established SRS guidelines, BED-comparable short-course WBRT administered to 23 Gy in 5 fractions (4.6 Gy/fraction) is safe and efficacious. Given previous literature indicating that nearly half of the patients prescribed traditional 2-week WBRT die without completing treatment, BED-comparable WBRT represents an attractive and promising WBRT alternative in this patient population.