In situ beta-irradiation of a brain arteriovenous malformation model.
OBJECTIVE
The treatment of large brain arteriovenous malformations (BAVMs) is challenging, and embolization alone is seldom curative. The study goal is to enhance the efficacy of arteriovenous malformation embolization by adding a beta-emitting isotope to the embolic agent.


METHODS
The pig rete mirabile was used as a BAVM model. The body distribution of radioactivity was evaluated after selective rete injection of N-butyl,2-cyanoacrylate mixed with (131)I-lipiodol in 8 animals using immediate whole body gamma-scintigraphy. Activities within the whole rete mirabile and selected tissue samples were quantified with a gamma counter immediately after sacrifice. Two pigs were submitted to serial gamma-scintigraphies for 6 weeks to detect delayed isotope leaching. Long-term effects of in situ irradiation were evaluated using a mixture of 188Re/N-butyl,2-cyanoacrylate in 8 pigs. In 1 animal, autoradiography was performed to evaluate local rete mirabile distribution of the radioactivity. Seven pigs were injected with 188Re/glue in 1 rete mirabile and with glue only on the opposite side, and the degree of vascular occlusion of both sides was compared on histology at 2 (n=2) or 6 months (n=5).


RESULTS
There was negligible activity outside the target. Radiation caused occlusion of vessels unreached by the glue itself but in the vicinity of the radioactive source in 5 of 7 rete mirabile.


CONCLUSIONS
Selective deposition of a beta-emitter inside a BAVM model may be achieved by current embolization techniques. The adjunct use of an isotope may increase the efficacy of embolization.
Roy
Daniel
D
Department of Radiology, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital Research Centre, Montreal, Quebec, Canada. daniel.roy.chum@ssss.gouv.qc.ca
Soucy
Jean-Paul
JP
Hartman
Neil G
NG
Janicki
Christian
C
Weill
Alain
A
Guilbert
François
F
Papineau
Karl
K
Raymond
Jean
J
D000818:Animals; D001165:Arteriovenous Malformations / Q000532:radiotherapy*; D001345:Autoradiography; D001921:Brain / Q000473:pathology*; D004621:Embolization, Therapeutic; D005720:Gamma Rays; D002538:Intracranial Arteriovenous Malformations / Q000532:radiotherapy*; D007459:Iodized Oil / Q000737:chemistry; D011827:Radiation; D011874:Radiometry; D011877:Radionuclide Imaging; D013552:Swine; D013997:Time Factors; D014916:Whole-Body Irradiation
D007459:Iodized Oil