Ultrasound and the blood-brain barrier.
High intensity focused ultrasound was employed to modify the permeability of the normal feline and canine blood-brain barrier (BBB) to a circulating vital dye--Evans blue (EB). The threshold doses (W sec/cm2) for focally increasing the permeability of the BBB in white matter (WM) and gray matter (GM) were as follows: internal capsule (WM)--340 to 680; thalamus (GM)--approximately 1326; and caudate nucleus (GM)--2284 to 2952. In the presence of supralesioning doses of ultrasound, the cross sectional area occupied by the EB was consistently greater than that of the attendant nonhemorrhagic lesion--thus suggesting that BBB changes may be inducible at sublesioning doses. These findings, in conjunction with those of others, suggest that high intensity focused ultrasound may have a role in the treatment of brain tumors based on cell destruction by two mechanisms: (a) direct, by the ultrasound and (b) indirect, by an antineoplastic agent which is delivered via an ultrasonically modified BBB.
Patrick
J T
JT
Department of Neurology, Indiana University School of Medicine, Indianapolis.
Nolting
M N
MN
Goss
S A
SA
Dines
K A
KA
Clendenon
J L
JL
Rea
M A
MA
Heimburger
R F
RF
D000818:Animals; D001479:Basal Ganglia / Q000033:anatomy & histology / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000502:physiology*; D001932:Brain Neoplasms / Q000628:therapy; D002415:Cats; D002421:Caudate Nucleus / Q000033:anatomy & histology / Q000378:metabolism; D004285:Dogs; D005070:Evans Blue / Q000493:pharmacokinetics; D010539:Permeability; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000033:anatomy & histology / Q000378:metabolism; D013997:Time Factors; D014464:Ultrasonic Therapy; D014465:Ultrasonics
D005070:Evans Blue