Radiosurgery for angiographically occult vascular malformations.

Area of Science:

• Neurosurgery
• Radiation Oncology
• Vascular Neurology

Background:

• Angiographically occult vascular malformations (AOVMs) present treatment challenges, especially when surgically inaccessible or in eloquent brain regions.
• Radiosurgery is a controversial but potential therapeutic option for select AOVM cases.

Purpose of the Study:

• To evaluate the efficacy of radiosurgery for AOVMs by reviewing hemorrhage rates, seizure control, and radiation-induced morbidity.
• To identify factors influencing treatment outcomes, such as radiation dosage and lesion location.

Main Methods:

• Systematic literature review of studies reporting on radiosurgery for AOVMs.
• Analysis of hemorrhage rates (overall and stratified by time post-treatment).
• Assessment of seizure control and radiation-induced complication rates.

Main Results:

• Overall hemorrhage rates ranged from 2-6.4%; post-radiosurgery rates were 1.6-8% within 2 years, decreasing to 0.8-5.2% after 2 years.
• Seizures were controlled in 31% and reduced in 35% of 291 patients.
• Radiation-induced morbidity varied (2.5-59%), with higher rates for brainstem lesions. Doses of 15-16.2 Gy showed lower morbidity (0-9.1%) and better long-term hemorrhage control compared to doses >= 16.5 Gy.

Conclusions:

• Stereotactic radiosurgery can be an effective treatment for AOVMs in surgically inaccessible locations, offering significant hemorrhage control and seizure reduction.
• Optimizing radiation doses (15-16.2 Gy) is crucial for minimizing treatment-related morbidity.
• Despite ongoing controversy, radiosurgery offers a viable option for select patients with AOVMs.