Leukoencephalopathy After SRS for Brain Metastases in Breast Cancer: Analysis of 1,077 Lesions

Overview

This retrospective study evaluated leukoencephalopathy incidence and severity following stereotactic radiosurgery (SRS) in 125 breast cancer patients with 1,077 brain metastases. Findings highlight the risk factors and progression patterns of white matter changes post-SRS, comparing outcomes with combined whole-brain radiation therapy (WBRT) and SRS.

Background

Breast cancer frequently metastasizes to the brain, with 7% to 16% of patients presenting brain lesions at diagnosis. While whole-brain radiation therapy (WBRT) has been a standard treatment, it is associated with significant neurocognitive side effects. Stereotactic radiosurgery (SRS) offers targeted high-dose radiation to brain metastases, potentially reducing adverse effects. Leukoencephalopathy, characterized by white matter changes, is a common delayed adverse radiation effect that impairs cognitive and motor functions.

Data Highlights

Key Findings

• Leukoencephalopathy grading used a 0–3 scale based on periventricular white matter changes on MRI FLAIR/T2 sequences.
• High-grade leukoencephalopathy (grades 2–3) was associated with increased integral radiation dose to the cranium and other clinical factors.
• Patients receiving combined WBRT and SRS showed different progression patterns of leukoencephalopathy compared to SRS alone.
• Leukoencephalopathy correlated with cognitive dysfunction symptoms such as memory and executive function impairment.
• Regular MRI follow-up every 3 months post-SRS enabled detailed volumetric tumor response and leukoencephalopathy progression assessment.

Clinical Implications

Clinicians should monitor for leukoencephalopathy in breast cancer patients undergoing SRS for brain metastases, especially those receiving higher integral radiation doses or combined WBRT. Early detection through MRI and grading of white matter changes can guide management to mitigate cognitive decline. Treatment planning should consider minimizing radiation exposure to reduce leukoencephalopathy risk.

Conclusion

This large single-institution study provides valuable insights into the incidence and risk factors of leukoencephalopathy following SRS in breast cancer brain metastases. Careful patient selection and radiation planning are essential to balance tumor control with preservation of neurological function.

References

1. Author/Source/Year -- Leukoencephalopathy After Stereotactic Radiosurgery for Brain Metastases in Breast Cancer