Radiation therapy for arteriovenous malformations: a review

Area of Science:

• Neurosurgery
• Radiation Oncology
• Vascular Neurology

Background:

• Arteriovenous malformations (AVMs) pose significant risks, including hemorrhage.
• Various radiation techniques have been employed for inoperable AVMs.
• Evaluating the efficacy and safety of different radiation modalities is crucial.

Purpose of the Study:

• To summarize and compare outcomes of different radiation therapies for inoperable AVMs.
• To review radiation-induced vascular changes and their implications.
• To assess the incidence of hemorrhage, mortality, and neurological deficits post-treatment.

Main Methods:

• Review of case reports and series involving partial brain irradiation, radiosurgery (Gamma Knife, linear accelerator), and Bragg peak therapy.
• Comparison of hemorrhage rates, mortality, and complication incidence across treatment modalities.
• Analysis of available data on AVM volume and radiation dose delivered to the nidus.

Main Results:

• Radiation therapy shows convincing evidence of obliterating carefully selected inoperable AVMs.
• Hemorrhage rates post-treatment (2-2.6% per year) are similar to natural history recurrence rates (2.2-3% per year).
• Mortality rates (0.6-5%) and permanent neurological deficits (1.7-4%) are lower than untreated AVMs (11% mortality).

Conclusions:

• Radiation therapy is a viable option for inoperable AVMs, particularly small lesions treated with focused radiation.
• The risks associated with radiation treatment are generally lower than the natural progression of untreated AVMs.
• Further data on treatment volume and dose are needed for historical techniques, while modern techniques offer more complete data.