Submitting Campus

Daytona Beach

Department

Mathematics

Document Type

Article

Publication/Presentation Date

7-15-2013

Abstract/Description

Purpose: to investigate the effect of variable dose rate on biologically effective dose ( BED ).

Materials and methods: by using the linear-quadratic (LQ) model with bi-exponential repair, we analytically determine the time-dependent dose rate R ~ which minimizes the effective protraction factor ( eff G ) and BEDunder the condition of fixed fraction time and dose per fraction.  Because normal tissue complication probability ( NTCP) monotonically decreases with decreasingBED , the dose rate R ~ also minimizes NTCP.

Results: the dependences of Geff, BED, and NTCP on fraction time were determined for different radiobiological parameters and two different dose rates: constant dose rate R0 and varying dose rate R.

Conclusion: the results of this study indicate that under certain conditions the reduction in BED for lateresponding tissues due to increased fraction time can be significantly greater than the reduction in BED for tumors. Our analysis also indicates that dose rate optimization can be radiobiologically beneficial because of the resulting decrease in NTCP.

Publication Title

International Journal of Radiation Biology

DOI

https://doi.org/10.3109/09553002.2013.811308

Publisher

Taylor & Francis

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