AVM Support UK Contact Details
Gamma Knife Centre
Information & Support Cromwell Hospital
For Patients Cromwell Road
AVM Support Group
Cramlington Patient Information
Tel: +44(0) 20 7460 5938
NE23 6JN Fax: +44(0) 20 7460 5940
Email: email@example.com on
Website: www.avmsupport.org.uk Gamma Knife Surgery
Office Hours: for
Tel: 01670 737 231 Monday – Friday 9am to 5.30pm
Reviewed March 2007
the groin area and a small skin incision made to al-
Treatment risks Gamma Knife Radiosurgery for low the passage of the catheter.
for AVM AVM The catheter is then placed in position and the con-
trast injected. At the same time several sets of X-
ray pictures may be taken of the artery or arteries.
The following information is given on Admission: Once finished the catheter is removed and a small
complications of gamma knife surgery: The patient is admitted to the Hospital on the dressing applied to the incision site.
morning of treatment. Patient preparation includes four
Although it is not a risk of the treatment, it should em- hours of fasting, hair shampooing and Dose Planning:
phasized that protection from brain haemorrhage is not pre-medication as needed. Dose planning involves simulating the radiation
afforded until the AVM has been completely closed by dose and shaping it in such a way that the
the treatment. Frame Fitting: radiation field conforms to the shape of the
The patient is brought down to the Gamma Knife Unit malformation. This maximises the dose to the AVM
Two factors are particularly important for the risks of for frame fitting. The hair is wiped with while minimising it to the surrounding
treatment by Gamma Knife surgery. These are the size alcohol and a local anaesthetic is injected at four sites on structures. The dose given is typically 18-25 Gy .
of and the location of the AVM. Undue effects are the head where the stereotactic frame will be fixed to the
usually caused by radiation induced swelling and/or external table of the skull using four screws. Frame Treatment:
injury to the brain close to the AVM. Injury may re- fixation takes approximately twenty minutes and the The patient is again brought down to the Gamma
sult in temporary or permanent deficits. The nature of injection of local anaesthetic is probably the most un- Knife Unit where treatment is carried out. Follow-
these deficits is related to which area of the brain is pleasant part of the whole procedure. ing completion, the stereotactic frame is removed
injured. Your consultant will inform you of the spe- and the patient is returned to their in-patient room.
cific risks in your case. With small AVM’s suitable MRI scanning: There may be some pressure headache within 12
for Gamma Knife surgery the risk is usually no higher Following application of the stereotactic frame hours of treatment due to the pressure caused by the
than 2-5%. a localiser box for MRI is attached to the frame frame. The patient usually remains in hospital for
and the patient is then transferred to the MRI one night. Many patients resume a normal lifestyle
Scanner where images are obtained using T1 as well as day after treatment.
T2 weighted imaging techniques. Images are trans-
ferred via the hospital network directly to the dose plan- Follow-up:
ning computer. The patient is then Your treating consultant should inform you of fol-
returned to their in-patient room while the dose planning low-up procedures. Clinical follow-up is routinely
is carried out. made at 1, 2 and 3 year intervals when an MRI
scan should be obtained. An angiogram is done
Angiogram: when the MRI. An angiogram is done when the
During this procedure contrast (also called dye) will be MRI indicates treatment success or after 3 years.
administered via an artery. Because we want to image
specific arteries in the brain, we use a Specialised cathe-
ter (tube). The tube is inserted through the femoral ar-
tery in the groin. A local anaesthetic will be injected into