title: The effect of hypothermia and hyperthermia on photodynamic therapy of normal brain.
abstract: The effect of whole body hyperthermia and hypothermia in conjunction with photodynamic therapy (PDT) was determined on normal rat brain. Hyperthermia animals (Group I, n = 18) were warmed until their core body temperature reached 40 degrees C, (brain temperature, 39.7 +/- 0.5 degree C) and maintained at 40 +/- 1 degree C for 30 minutes prior to and after PDT. Hypothermia (Group II, n = 31) animals were cooled to 30 +/- 1 degree C (brain temperature, 29.3 +/- 0.4 degree C) for 1 hour. PDT treatment was performed, and the body temperature of the animals was maintained at 30 degrees C for 2 hours post-PDT. A population of animals was subjected to PDT under normothermic (Group III, n = 16; body temperature, 37 +/- 1 degree C; brain temperature, 36.7 +/- 0.8 degree C) conditions and treated in a manner identical to that of hyperthermic animals. PDT was performed with 17 J/cm2, 35 J/cm2, or 70 J/cm2 (100 mW/cm2). Photofrin (Quadralogic Technologies Ltd., Vancouver, Canada) (12.5 mg/kg) was injected intraperitoneally 48 hours prior to laser treatment on all three groups. Wet-dry weight measurements were obtained on a separate set of all three groups of animals (n = 27). Cortical lesion depths were measured, and pathological evaluation was made at 24 hours post-PDT. No difference in the wet-dry weight measurements or histopathology was present between the three groups of animals. Lesion depths for Group I animals did not significantly differ from Group III animals.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan.
authors.forename: M O
authors.initials: MO
authors.lastname: Dereski
authors.forename: L
authors.initials: L
authors.lastname: Madigan
authors.forename: M
authors.initials: M
authors.lastname: Chopp
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000473:pathology; D002540:Cerebral Cortex / Q000187:drug effects / Q000473:pathology; D006414:Hematoporphyrin Photoradiation; D006979:Hyperthermia, Induced; D007036:Hypothermia, Induced; D008297:Male; D009336:Necrosis; D009410:Nerve Degeneration / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344