Radiosurgery with or without A 2-mm margin for 93 single brain metastases

Area of Science:

• Neurosurgery
• Radiation Oncology
• Medical Imaging

Background:

• Brain metastases are a common complication of systemic cancer.
• Linac-based radiosurgery (RS) is a treatment option for single brain metastases.
• The optimal margin for RS in brain metastases is debated.

Purpose of the Study:

• To compare the efficacy and safety of Linac radiosurgery with and without a 2-mm margin for single brain metastases.
• To evaluate the impact of a 2-mm margin on local control, survival, and complications.

Main Methods:

• Retrospective comparison of 93 patients with single brain metastases treated with Linac RS.
• Patients were divided into two groups: classic RS (42 patients) and 2-mm margin RS (51 patients).
• Exclusion of 30 patients with multiple lesions. Data collected on local control, survival, and complications.

Main Results:

• No significant difference in 1- or 2-year local control rates between the two groups.
• Median survival was 11.3 months for classic RS and 19 months for margin RS (not statistically significant).
• The 2-mm margin group had a significantly higher rate of severe parenchymal complications (19.6% vs. 7.1%, p=0.02).

Conclusions:

• A 2-mm margin in Linac radiosurgery for single brain metastases does not improve local control or survival.
• The 2-mm margin is associated with an increased risk of severe parenchymal complications.
• This approach is not recommended; further research with advanced imaging and stereotactic hypofractionation is suggested.