Protocol for Staged Stereotactic Radiosurgery for Large Arteriovenous Malformations
Protocol for Staged Stereotactic Radiosurgery for Large Arteriovenous Malformations
Stereotactic radiosurgery is a well established treatment option for arteriovenous
 malformations (AVMs). The potential complications related to radiosurgery are well documented
 and are predominately related to radiation effects to the surrounding brain parenchyma. These
 risks increase with larger lesions, requiring a concommitant reduction in the amount of
 radiation that can be delivered. This reduction in radiation dose decreases the efficacy of
 treatment. The broad, long-term objectives of this proposal are 1) to determine the role of
 fractionated stereotactic radiosurgery in the treatment of large (>10cc) AVMs; 2) to evaluate
 the complication rates related to fractionating these doses compared to conventional
 stereotactic treatment 3) to evaluate the success rate of treating large AVMs with this
 protocol.
This research project will involve performing a preoperative MRI and angiogram on patients
 harboring an AVM to determine the feasibility of treating the lesion with gamma knife
 radiosurgery. Patient with lesions greater than 10 cc will be studied.

 Each patient will have a Magnetic resonance angiography (MRA) with gadolinium and an
 angiogram immediately before each radiation treatment. If there is a contraindication for MRI
 examination (pacemaker or any other implanted ferromagnetic material), a CT angiogram will be
 obtained instead. Each treatment will be spaced at least 3 months apart. Follow-up MRIs or CT
 scans will be obtained at 6 month intervals. A follow-up angiogram will be obtained when
 there is radiographic evidence of complete occlusion based on the MRI images, or at 3 years
 after the procedure, whichever occurs first.
Inclusion Criteria:

 -  All patients age 18 or older

 -  Inpatients and outpatients, referred for radiosurgical treatment of an arteriovenous
 malformation

 -  Patients with lesions greater than 10 cc, who are currently symptomatic from the AVM
 (hemorrhage, seizure, or ischemia from steal phenomenon)

 Exclusion Criteria:

 -  Patients without symptoms related to AVM