Retrospective analysis of imaging techniques for treatment planning and monitoring of obliteration for gamma knife treatment of cerebral arteriovenous malformation.
BACKGROUND
It has been well established that Gamma Knife radiosurgery (GKS) is an effective treatment for brain arteriovenous malformations (AVMs).


OBJECTIVE
To evaluate complete obliteration rates for magnetic resonance imaging (MRI)-based GKS treatment planning performed with and without angiography and to conduct a preliminary assessment of the utility of using pulsed arterial spin labeling (PASL) magnetic resonance (MR) perfusion imaging to confirm complete obliteration.


METHODS
Forty-six patients were identified who had undergone GKS without embolization with a minimum follow-up of 2 years. One group was planned with integrated stereotactic angiography and MR (spoiled gradient recalled) images obtained on the day of GKS. A second technique avoided the risk of arteriography by using only axial MR images. Beginning in 2007, PASL MR perfusion imaging was routinely performed as a portion of the follow-up MRI to assess the restoration of normal blood flow of the nidus and surrounding area.


RESULTS
The overall obliteration rate for the angiography/MRI group was 88.0% (29 of 33). Patients in the MRI-only group had an obliteration rate of 61.5% (8 of 13), with P=.092 with the Fisher exact test, which is not statistically significant. A Kaplan-Meier analysis was also not statistically significant (log rank test, P=.474). Four of 9 patients with incomplete obliteration on angiography also had shown residual abnormal blood flow on PASL imaging.


CONCLUSIONS
This retrospective analysis shows that treatment planning technique used in GKS does not play a role in the eventual obliteration of treated AVMs. PASL may have potential in the evaluation of AVM obliteration.
Departments of *Neurosurgery and ‡Radiation Oncology §Division of Public Health Sciences, Wake Forest Baptist Medical Center, Winston-Salem, North Carolina.
Kwame
K
Amponsah
Thomas L
TL
Ellis
Michael D
MD
Chan
James F
JF
Lovato
J Daniel
JD
Bourland
Allan F
AF
deGuzman
Kenneth E
KE
Ekstrand
Michael T
MT
Munley
Kevin P
KP
McMullen
Edward G
EG
Shaw
Stephen B
SB
Tatter
D000293:Adolescent; D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D002533:Cerebral Angiography; D002648:Child; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000379:methods*; D012189:Retrospective Studies; D013113:Spin Labels; D016896:Treatment Outcome; D055815:Young Adult
D013113:Spin Labels