title: Radiosensitivity uncertainty evaluation for the in vitro biophysical modeling of EMT6 cells.
abstract: OBJECTIVE
  The aims of this study were to evaluate the cell survival uncertainty distribution of radiation and to assess the accuracy of predictions of tumor response by using three different in vitro experimental cell cultures with radiosensitizers (including etanidazole).
  
  
  METHODS
  Using EMT6 cells and X-rays, the cell survival fraction was obtained from 15, 34, and 21 different experiments under normoxic, hypoxic, and hypoxic-plus-radiosensitizer culture, respectively.
  
  
  RESULTS
  The α coefficients were 0.257 ± 0.188, 0.078 ± 0.080, and 0.182 ± 0.116 Gy(-1), respectively. The β coefficients were 0.0159 ± 0.0208, 0.0076 ± 0.0113, and 0.0062 ± 0.0077 Gy(-2), respectively. The α coefficient and the dose that killed half of the clonogens population (D50) were significantly different between normoxic cell and hypoxic cell cultures (p<0.01), respectively. The use of radiosensitizers under hypoxic conditions improved radiosensitivity.
  
  
  CONCLUSIONS
  Our results suggest that parameter value distributions are required for biophysical modeling of applications for radiotherapy.
authors: Department of Radiological Technology, Graduate School of Health Sciences, Okayama University, Okayama, Japan Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, Tokushima, Japan oita-m@cc.okayama-u.ac.jp.
authors: Masataka
authors: M
authors: Oita
authors: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, Tokushima, Japan.
authors: Yoshihiro
authors: Y
authors: Uto
authors: Department of Radiological Technology, Institute of Health Biosciences, Graduate School, The University of Tokushima, Tokushima, Japan.
authors: Masahide
authors: M
authors: Tominaga
authors: Department of Radiology, Tokushima University Hospital, Tokushima, Japan.
authors: Motoharu
authors: M
authors: Sasaki
authors: Department of Radiology, Tokushima University Hospital, Tokushima, Japan.
authors: Yasuo
authors: Y
authors: Hara
authors: Department of Radiology, Tokushima University Hospital, Tokushima, Japan.
authors: Taro
authors: T
authors: Kishi
authors: Department of Life System, Institute of Technology and Science, Graduate School, The University of Tokushima, Tokushima, Japan.
authors: Hitoshi
authors: H
authors: Hori
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000528:radiation effects; D005260:Female; D008325:Mammary Neoplasms, Experimental / Q000473:pathology / Q000532:radiotherapy*; D051379:Mice; D008954:Models, Biological; D011836:Radiation Tolerance; D035501:Uncertainty
keywords: Radiotherapy; biophysical modelling; in vitro; radiosensitivity uncertainty