Linac-based stereotactic radiosurgery for brain arteriovenous malformations

Area of Science:

• Neurosurgery
• Radiation Oncology
• Radiosurgery

Background:

• Gamma knife radiosurgery is common for cerebral arteriovenous malformations (AVMs), but linac-based radiosurgery is gaining popularity.
• The efficacy of combined endovascular and radiosurgical treatment for AVMs remains uncertain.

Purpose of the Study:

• Evaluate obliteration and rebleeding rates after linac-based stereotactic radiosurgery for cerebral AVMs.
• Identify factors influencing obliteration and adverse effects.

Main Methods:

• Analysis of 62 consecutive patients with cerebral AVMs treated with linac-based radiosurgery.
• Inclusion of patients with prior embolisation or surgery.
• Kaplan-Meier survival and life table analyses for obliteration and bleeding rates.

Main Results:

• Actuarial obliteration rates were 17% (1 year), 36% (2 years), and 40% (3 years).
• Prior embolisation did not impact obliteration rates.
• Significant factors for obliteration included Spetzler-Martin grade, AVM score, radiation dose, volume, and nidus size (<3cm).
• Doses <15Gy reduced obliteration probability; bleeding risk decreased over time.

Conclusions:

• A minimum 3-year follow-up is necessary for accurate outcome assessment.
• Optimal outcomes are observed in small (<3cm), low-grade AVMs with low AVM scores.
• Stereotactic radiosurgery leads to a gradually decreasing bleeding risk post-treatment.