Hypofractionated conformal stereotactic radiotherapy for arteriovenous malformations

Area of Science:

• Neurology
• Radiology
• Vascular Surgery

Background:

• Arteriovenous malformations (AVMs) are congenital vascular lesions with significant morbidity and mortality risks if untreated.
• Conventional single-fraction radiotherapy for large AVMs presents challenges in safety and efficacy.
• Radiotherapy is a recognized treatment modality for AVMs.

Purpose of the Study:

• To evaluate the efficacy and safety of hypofractionated conformal stereotactic radiotherapy for cerebral AVMs.
• To compare obliteration rates in different AVM volume groups.
• To assess the long-term outcomes of this radiotherapy technique.

Main Methods:

• A cohort of 36 patients with cerebral AVMs were treated with hypofractionated conformal stereotactic radiotherapy between 1986 and 2001.
• Twenty-nine patients underwent follow-up angiography to assess treatment outcomes.
• AVM volumes were recorded, and obliteration rates were analyzed at 2 and 5 years post-treatment.

Main Results:

• Complete AVM obliteration was achieved in 83% of the 29 evaluated patients.
• At 2 years, obliteration rates were 56% for AVMs 4-10 cm³ and 50% for AVMs >10 cm³.
• At 5 years, obliteration rates increased to 81% for AVMs 4-10 cm³ and 70% for AVMs >10 cm³.

Conclusions:

• Hypofractionated conformal stereotactic radiotherapy is a potentially valuable alternative for treating large or eloquenty located AVMs.
• This technique allows for higher radiation doses compared to single-fraction radiosurgery.
• The obliteration rates achieved were comparable to single-dose radiosurgery, even for larger AVM volumes.