Evaluation of the Combined Effects of Hyperthermia, Cobalt-60 Gamma Rays and Iudr on Cultured Glioblastoma Spheroid Cells and Dosimetry Using Tld-100

Objective: in radiation treatment, the irradiation which is effective enough to control thetumors far exceeds normal-tissues tolerance. thus to avoid such unfavourable outcomes,some methods sensitizing the tumor cells to radiation are used. iododeoxyuridine (iudr)is a halogenated thymidine analogue that known to be effective as a radiosensitizer in humancancer therapy. improving the potential efficacy of radiation therapy after combiningto hyperthermia depends on the magnitude of the differential sensitization of the hyperthermiceffects or on the differential cytotoxicity of the radiation effects on the tumor cells.in this study, we evaluated the combined effects of iudr, hyperthermia and gamma raysof 60co on human glioblastoma spheroids culture.materials and methods: in this experimental study,the cultured spheroids with 100?m diameterwere treated by 1 ?m iudr, 43?c hyperthermia for an hour and 2 gy gamma rays,respectively. the dna damages induced in cells were compared using alkaline cometassay method, and dosimetry was then performed by tld-100. comet scores were calculatedas mean ± standard error of mean (sem) using one-way anova.results:comparison of dna damages induced by iudr and hyperthermia + gamma treatmentshowed 2.67- and 1.92-fold enhancement, respectively, as compared to the damagesinduced by radiation alone or radiation combined iudr. dosimetry results showedthe accurate dose delivered to cells.conclusion: analysis of the comet tail moments of spheroids showed that the radiationtreatments combined with hyperthermia and iudr caused significant radiosensitizationwhen compared to related results of irradiation alone or of irradiation with iudr. these resultssuggest a potential clinical advantage of combining radiation with hyperthermia andindicate effectiveness of hyperthermia treatment in inducing cytotoxicity of tumor cells.