The role of photodynamic therapy in posterior fossa brain tumors. A preclinical study in a canine glioma model.
Photodynamic therapy was studied in dogs with and without posterior fossa glioblastomas. This mode of therapy consisted of intravenous administration of Photofrin-II at doses ranging from 0.75 to 4 mg/kg 24 hours prior to laser light irradiation in the posterior fossa. Tissue levels of Photofrin-II were four times greater in the tumor than in the surrounding normal brain. Irradiation was performed using 1 hour of 500 mW laser light at a wavelength of 630 nm delivered through a fiberoptic catheter directly into the tumor bed via a burr hole. All animals receiving a high dose (4 or 2 mg/kg) of Photofrin-II developed serious brain-stem neurotoxicity resulting in death or significant residual neurological deficits. A lower dose (0.75 mg/kg) of Photofrin-II produced tumor kill without significant permanent brain-stem toxicity in either the control animals or the animals with cerebellar brain tumors receiving photodynamic therapy.
Whelan
H T
HT
Department of Neurology, Medical College of Wisconsin, MACC Fund Research Center, Milwaukee.
Schmidt
M H
MH
Segura
A D
AD
McAuliffe
T L
TL
Bajic
D M
DM
Murray
K J
KJ
Moulder
J E
JE
Strother
D R
DR
Thomas
J P
JP
Meyer
G A
GA
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003388:Cranial Fossa, Posterior; D017323:Dihematoporphyrin Ether / Q000493:pharmacokinetics / Q000627:therapeutic use; D004285:Dogs; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008279:Magnetic Resonance Imaging; D010778:Photochemotherapy; D012016:Reference Values
D017323:Dihematoporphyrin Ether