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Title: {alpha}/{beta} ratio: A dose range dependence study

Abstract

Purpose: To investigate the dependence of the {alpha}/{beta} ratio determined from in vitro survival curves on the dose ranges. Methods: Detailed clonogenic cell survival experiments were used to determine the least squares estimators for the linear quadratic model for different dose ranges. The cell lines used were CHO AA8, a Chinese hamster fibroblast cell line; U-373 MG, a human glioblastoma cell line; and CP3 and DU-145, two human prostate carcinoma cell lines. The {alpha}, {beta}, and {alpha}/{beta} ratio behaviors, combined with a goodness-of-fit analysis and Monte Carlo simulation of the experiments, were assessed within different dose regions. Results: Including data from the low-dose region has a significant influence on the determination of the {alpha}, {beta}, and {alpha}/{beta} ratio from in vitro survival curve data. In this region, the values are poorly determined and have significant variability. The mid-dose region is characterized by more precise and stable values and is in agreement with the linear quadratic model. The high-dose region shows relatively small statistical error in the fitted parameters but the goodness-of-fit and Monte Carlo analyses showed poor quality fits. Conclusion: The dependence of the fitted {alpha} and {beta} on the dose range has an impact on the {alpha}/{beta} ratio determinedmore » from the survival data. The low-dose region had a significant influence that could be a result of a strong linear, rather than quadratic, component, hypersensitivity, and adaptive responses. This dose dependence should be interpreted as a caution against using inadequate in vitro cell survival data for {alpha}/{beta} ratio determination.« less

Authors:
 [1];  [2];  [3];  [2];  [3]
  1. Department of Physics, Carleton University, Ottawa, ON (Canada) and Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON (Canada). E-mail: logarcia@ottawahospital.on.ca
  2. Department of Physics, Carleton University, Ottawa, ON (Canada)
  3. (Canada)
Publication Date:
OSTI Identifier:
20944706
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Radiation Oncology, Biology and Physics; Journal Volume: 67; Journal Issue: 2; Other Information: DOI: 10.1016/j.ijrobp.2006.10.017; PII: S0360-3016(06)03345-1; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; CARCINOMAS; COMPUTERIZED SIMULATION; FIBROBLASTS; GLIOMAS; HAMSTERS; IN VITRO; LEAST SQUARE FIT; MONTE CARLO METHOD; PROSTATE; RADIATION DOSES; SURVIVAL CURVES

Citation Formats

Garcia, Lourdes M., Wilkins, David E., Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON, Raaphorst, Gijsbert P., and Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON. {alpha}/{beta} ratio: A dose range dependence study. United States: N. p., 2007. Web. doi:10.1016/j.ijrobp.2006.10.017.
Garcia, Lourdes M., Wilkins, David E., Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON, Raaphorst, Gijsbert P., & Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON. {alpha}/{beta} ratio: A dose range dependence study. United States. doi:10.1016/j.ijrobp.2006.10.017.
Garcia, Lourdes M., Wilkins, David E., Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON, Raaphorst, Gijsbert P., and Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON. Thu . "{alpha}/{beta} ratio: A dose range dependence study". United States. doi:10.1016/j.ijrobp.2006.10.017.
@article{osti_20944706,
title = {{alpha}/{beta} ratio: A dose range dependence study},
author = {Garcia, Lourdes M. and Wilkins, David E. and Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON and Raaphorst, Gijsbert P. and Department of Medical Physics, Ottawa Hospital Regional Cancer Center, Ottawa, ON},
abstractNote = {Purpose: To investigate the dependence of the {alpha}/{beta} ratio determined from in vitro survival curves on the dose ranges. Methods: Detailed clonogenic cell survival experiments were used to determine the least squares estimators for the linear quadratic model for different dose ranges. The cell lines used were CHO AA8, a Chinese hamster fibroblast cell line; U-373 MG, a human glioblastoma cell line; and CP3 and DU-145, two human prostate carcinoma cell lines. The {alpha}, {beta}, and {alpha}/{beta} ratio behaviors, combined with a goodness-of-fit analysis and Monte Carlo simulation of the experiments, were assessed within different dose regions. Results: Including data from the low-dose region has a significant influence on the determination of the {alpha}, {beta}, and {alpha}/{beta} ratio from in vitro survival curve data. In this region, the values are poorly determined and have significant variability. The mid-dose region is characterized by more precise and stable values and is in agreement with the linear quadratic model. The high-dose region shows relatively small statistical error in the fitted parameters but the goodness-of-fit and Monte Carlo analyses showed poor quality fits. Conclusion: The dependence of the fitted {alpha} and {beta} on the dose range has an impact on the {alpha}/{beta} ratio determined from the survival data. The low-dose region had a significant influence that could be a result of a strong linear, rather than quadratic, component, hypersensitivity, and adaptive responses. This dose dependence should be interpreted as a caution against using inadequate in vitro cell survival data for {alpha}/{beta} ratio determination.},
doi = {10.1016/j.ijrobp.2006.10.017},
journal = {International Journal of Radiation Oncology, Biology and Physics},
number = 2,
volume = 67,
place = {United States},
year = {Thu Feb 01 00:00:00 EST 2007},
month = {Thu Feb 01 00:00:00 EST 2007}
}