Treatment Outcomes After Higher-dose Fractionated Stereotactic Radiotherapy (FSRT) Alone for 1-4 Brain Metastases.

Area of Science:

• Neurology
• Radiation Oncology
• Oncology

Background:

• Fractionated stereotactic radiotherapy (FSRT) is a growing treatment for brain metastases.
• Investigating higher biologically effective doses (BED) of FSRT is crucial for optimizing outcomes.
• Understanding the impact of FSRT dose on local control, survival, and radiation necrosis is essential.

Purpose of the Study:

• To evaluate the efficacy and safety of higher-dose FSRT for brain metastases.
• To determine the association between different BED levels and clinical outcomes.
• To assess factors influencing local control, overall survival, and radiation necrosis.

Main Methods:

• Retrospective analysis of 69 patients with 1-4 brain metastases treated with FSRT.
• Eleven patient and treatment characteristics were evaluated.
• Outcomes assessed included local control (LC), overall survival (OS), and freedom from radiation necrosis (RN).

Main Results:

• At 1 and 2 years, LC rates were 81% and 63%, OS rates were 66% and 43%, and freedom from RN rates were 98% and 87%.
• Higher BED (63-66.7 Gy12) was not associated with improved LC or OS compared to lower BED (49.6-57 Gy12).
• Lower BED was associated with higher rates of freedom from RN (p=0.046). Karnofsky Performance Score (KPS) ≥90 correlated with better OS (p=0.048).

Conclusions:

• Higher-dose FSRT is feasible and effective for patients with limited brain metastases.
• BED 63-66.7 Gy12 may not offer additional benefits in LC or OS and could elevate RN risk.
• Further research is needed to refine optimal FSRT dosing strategies for brain metastases.