title: Evaluation of The Combined Effects of Hyperthermia, Cobalt-60 Gamma Rays and IUdR on Cultured Glioblastoma Spheroid Cells and Dosimetry Using TLD-100.
abstract: OBJECTIVE
  In radiation treatment, the irradiation which is effective enough to control the tumors 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 human cancer therapy. Improving the potential efficacy of radiation therapy after combining to hyperthermia depends on the magnitude of the differential sensitization of the hyperthermic effects 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 rays of (60)Co on human glioblastoma spheroids culture.
  
  
  METHODS
  In this experimental study,the cultured spheroids with 100µm diameter were treated by 1 µM IUdR, 43°C hyperthermia for an hour and 2 Gy gamma rays, respectively. The DNA damages induced in cells were compared using alkaline comet assay method, and dosimetry was then performed by TLD-100. Comet scores were calculated as mean ± standard error of mean (SEM) using one-way ANOVA.
  
  
  RESULTS
  Comparison of DNA damages induced by IUdR and hyperthermia + gamma treatment showed 2.67- and 1.92-fold enhancement, respectively, as compared to the damages induced by radiation alone or radiation combined IUdR. Dosimetry results showed the accurate dose delivered to cells.
  
  
  CONCLUSIONS
  Analysis of the comet tail moments of spheroids showed that the radiation treatments combined with hyperthermia and IUdR caused significant radiosensitization when compared to related results of irradiation alone or of irradiation with IUdR. These results suggest a potential clinical advantage of combining radiation with hyperthermia and indicate effectiveness of hyperthermia treatment in inducing cytotoxicity of tumor cells.
authors.affiliation: Department of Radiobiology, Iran University of Allied Health, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Neshasteh-Riz
authors.affiliation: Department of Nuclear Engineering, Science and Research Islamic Azad University, Tehran, Iran.
authors.forename: Rozhin
authors.initials: R
authors.lastname: Rahdani
authors.affiliation: Department of Medical Physics, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mostaar
keywords: Comet Assay; Glioblastoma; Hyperthermia; IUdR; Radiation