CyberKnife Robotic Radiosurgery System for Treating Large Brain Metastases: A Single-Center Cohort Study.

Area of Science:

• Neurosurgery
• Radiation Oncology
• Oncology

Background:

• Large brain metastases (≥10 cm³) present challenges in balancing treatment efficacy and toxicity.
• Hypofractionated stereotactic radiosurgery (HF-SRS) is an evolving technique for brain metastases.
• Evaluating HF-SRS for larger lesions is crucial for optimizing patient outcomes.

Purpose of the Study:

• To assess the efficacy and safety of HF-SRS using the CyberKnife system for brain metastases ≥10 cm³.
• To determine local control and overall survival rates in patients treated with HF-SRS.
• To evaluate the incidence of radiation necrosis following HF-SRS for large brain metastases.

Main Methods:

• Retrospective study of 63 patients with 65 large brain metastases (≥10 cm³).
• Treatment involved HF-SRS with a median dose of 30 Gy in 3 fractions.
• Local control, overall survival, and radiation necrosis were evaluated using Kaplan-Meier and Cox regression models.

Main Results:

• High local tumor control rates: 100% at 6 and 12 months, 92.58% at 18 months.
• Excellent survival outcomes: 6-, 12-, and 18-month survival rates of 95.24%, 82.51%, and 68.61%, respectively.
• Low cumulative incidence of radiation necrosis: 7.02% at 1 year and 14.04% at 18 months.

Conclusions:

• HF-SRS demonstrates favorable local control for large brain metastases (≥10 cm³).
• The technique offers promising overall survival rates with a manageable toxicity profile.
• HF-SRS is a viable and effective treatment option for larger brain metastases.