title: Thermotolerance effects on thermoradiosensitization in human glioma cells.
abstract: Human glioma cells were tested to evaluate thermotolerance (TT) development and its effect on radiosensitization. The data show that long duration mild hyperthermia (LDMH) at 40, 41 and 42 degrees C when given before acute irradiation resulted in increased radiosensitization with heating time. Furthermore, radiosensitization was not reduced by TT. When LDMH was given before 45 degrees C hyperthermia there was evidence of TT development which reduced radiosensitization compared to heating at 45 degrees C alone. For 40 and 41 degrees C heating the effect was maximum for the 8 h heating time while for 42 degrees C it was generally maximum for the 4 h heating time. At longer heating times of 24 to 48 h the effect of TT declined. Thus while LDMH itself does not display TT for radiosensitization it can in fact produce a TT effect on radiosensitization when used in a stepup-heating protocol with 45 degrees C.
authors.affiliation: Ottawa Regional Cancer Centre, Ontario, Canada.
authors.forename: G P
authors.initials: GP
authors.lastname: Raaphorst
authors.forename: J P
authors.initials: JP
authors.lastname: Mao
authors.forename: C E
authors.initials: CE
authors.lastname: Ng
mesh_terms: D002453:Cell Cycle / Q000502:physiology; D002470:Cell Survival / Q000528:radiation effects; D005910:Glioma / Q000628:therapy*; D006801:Humans; D006979:Hyperthermia, Induced; D011836:Radiation Tolerance; D013696:Temperature; D014407:Tumor Cells, Cultured; D014965:X-Rays / Q000009:adverse effects