Article
Use of Radiation Protraction to Escalate Biologically Effective Dose to the Treatment Target
Medical Physics
(2011)
Abstract
Purpose: The aim of this study is to evaluate how simultaneously increasing fraction time and dose per fraction affect biologically effective dose for the target (BEDtar) while biologically effective dose for the normal tissue (BEDnt) is fixed.
Methods: In this investigation, BEDtar and BEDnt were studied by assuming mono-exponential repair of sublethal damage with tissue dependent repair half-time.
Results: Our results demonstrate that under certain conditions simultaneously increasing fraction time and dose per fraction result in increased BEDtar while BEDnt is fixed. The dependence of biologically effective dose on fraction time is influenced by the dose rate. In this investigation we analytically determined time-varying dose rate R~ which minimizes BED. Changes in BED with fraction time were compared for constant dose rate and for R~.
Conclusions: A number of recent experimental and theoretical studies have demonstrated that slow delivery of radiation (known as radiation protraction) leads to reduced therapeutic effect because of increased repair of sublethal damage. In contrast, our analysis shows that under certain conditions simultaneously increasing fraction time and dose per fraction are radiobiologically advantageous.
Keywords
- Biologically effective dose,
- radiation protraction,
- sublethal damage repair
Disciplines
Publication Date
November 21, 2011
DOI
https://doi.org/10.1118/1.3656053
Publisher Statement
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Citation Information
V. Y. Kuperman and G. S. Spradlin. "Use of Radiation Protraction to Escalate Biologically Effective Dose to the Treatment Target" Medical Physics Vol. 38 Iss. 12 (2011) p. 6553 - 6560 ISSN: 0094-2405 Available at: http://works.bepress.com/greg_spradlin/20/