Effect of Variable Dose Rate On Biologically Effective Dose

Vadim Y. Kuperman; Greg S. Spradlin

doi:10.3109/09553002.2013.811308

Effect of Variable Dose Rate On Biologically Effective Dose

Research output: Contribution to journal › Article › peer-review

Abstract

 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  which minimizes the effective protraction factor (Geff) and BED under the condition of fixed fraction time and dose per fraction. Because normal tissue complication probability (NTCP) monotonically decreases with decreasing BED, the dose rate  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 .
 
 Conclusion: The results of this study indicate that under certain conditions the reduction in BED for late-responding 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.

Original language	American English
Journal	International Journal of Radiation Biology
Volume	89
DOIs	https://doi.org/10.3109/09553002.2013.811308
State	Published - Jul 15 2013
Externally published	Yes

Keywords

Radiation protraction
sublethal damage repair

Disciplines

Medicine and Health Sciences
Mathematics

Access to Document

10.3109/09553002.2013.811308License: Unspecified

Cite this

@article{5471fc2ae6e54245a217b17d2e5160e3,

title = "Effect of Variable Dose Rate On Biologically Effective Dose",

abstract = " 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 which minimizes the effective protraction factor (Geff) and BED under the condition of fixed fraction time and dose per fraction. Because normal tissue complication probability (NTCP) monotonically decreases with decreasing BED, the dose rate 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 . Conclusion: The results of this study indicate that under certain conditions the reduction in BED for late-responding 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.",

keywords = "Radiation protraction, sublethal damage repair",

author = "Kuperman, {Vadim Y.} and Spradlin, {Greg S.}",

year = "2013",

month = jul,

day = "15",

doi = "10.3109/09553002.2013.811308",

language = "American English",

volume = "89",

journal = "International Journal of Radiation Biology",

issn = "1362-3095",

}

TY - JOUR

T1 - Effect of Variable Dose Rate On Biologically Effective Dose

AU - Kuperman, Vadim Y.

AU - Spradlin, Greg S.

PY - 2013/7/15

Y1 - 2013/7/15

N2 - 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 which minimizes the effective protraction factor (Geff) and BED under the condition of fixed fraction time and dose per fraction. Because normal tissue complication probability (NTCP) monotonically decreases with decreasing BED, the dose rate 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 . Conclusion: The results of this study indicate that under certain conditions the reduction in BED for late-responding 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.

AB - 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 which minimizes the effective protraction factor (Geff) and BED under the condition of fixed fraction time and dose per fraction. Because normal tissue complication probability (NTCP) monotonically decreases with decreasing BED, the dose rate 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 . Conclusion: The results of this study indicate that under certain conditions the reduction in BED for late-responding 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.

KW - Radiation protraction

KW - sublethal damage repair

U2 - 10.3109/09553002.2013.811308

DO - 10.3109/09553002.2013.811308

M3 - Article

SN - 1362-3095

VL - 89

JO - International Journal of Radiation Biology

JF - International Journal of Radiation Biology

ER -