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Last data update: 2014.03.03

R: Linear Quadratic Extrapolated (LQE) Dose Conversion

LQE	R Documentation

Linear Quadratic Extrapolated (LQE) Dose Conversion

Description

This function and its associated methods calculate LQE-weighted dose(s) for a given DVH or DVH.list object, allowing iso-effect conversion between one or more DVH(s) employing different dose fractionation.

Usage

## S4 method for signature 'DVH,numeric'
LQE(x, aB, fractions = NULL, N = NULL, dose.units = c("cGy", "Gy"))

## S4 method for signature 'DVH.list,numeric'
LQE(x, aB, fractions = NULL, N = NULL, dose.units = NULL)	

## S4 method for signature 'numeric,numeric'
LQE(x, aB, fractions = NULL, N = NULL, dose.units = c("cGy", "Gy"))

Arguments

`x`	Can represent either numeric value(s) or otherwise an object of class `DVH` or `DVH.list` for which to calculate isoeffective dose(s) based on LQE. Note that input doses should be specified in units of `dose.units` (default is `"cGy"`).
`aB`	Numeric value specifying tissue-specific parameter "alpha/beta ratio". Multiple values may be specified for LQE conversion of `x`, where `x` is a `DVH.list` object containing multiple `DVH` objects.
`fractions`	Numeric value specifying the fraction sizes in which doses are deposited. Multiple values may be specified for LQE conversion of `x`, where `x` is a `DVH.list` object containing multiple `DVH` objects. Two values should be specified when `x` contains numeric value(s), with the first element representing the fractionation for the input dose and the second element used to compute iso-effective output dose. Only a single value should be used to calculate iso-effective doses for a single `DVH` input.
`N`	Numeric value specifying the number of fractions in which doses are deposited. Multiple values may be specified for LQE conversion of `x`, where `x` is a `DVH.list` object containing multiple `DVH` objects. Two values should be specified when `x` contains numeric value(s), with the first element representing the fractionation for the input dose and the second element used to compute iso-effective output dose. Only a single value should be used to calculate iso-effective doses for a single `DVH` input. Note that parameter `N` is ignored unless `fractions=NULL`.
`dose.units`	Value specifying output dose units (must be one of `"cGy"` or `"Gy"`). Note that this value also determines input dose units when `x` is numeric. Multiple values may be specified for LQE conversion of `x`, where `x` is a `DVH.list` object containing multiple `DVH` objects.

Value

Returns a DVH or DVH.list object, corresponding to original input type for parameter x.

Author(s)

Reid F. Thompson (reid.thompson@gmail.com)

References

Barendsen, G.W. (1982) Dose fractionation, dose-rate and iso-effect relationships for normal-tissue response. Int J Radiat Oncol Biol Phys 8(11):1981-1997.

Examples

# 5x 300cGy == 9x 200cGy (1800cGy isoeffective dose)
LQE(1500, aB=3, fractions=c(300, 200), dose.units="cGy")
LQE(15, aB=3, N=c(5, 9), dose.units="Gy")
LQE(18, aB=3, fractions=c(2, 3), dose.units="Gy")

# Multiple simultaneous numerical queries
LQE(c(4500, 5400), aB=3, fractions=c(300, 200), dose.units="cGy")

# DVH processing
LQE(janedoe[["LIVER"]],aB=3,fractions=200,dose.units="cGy")

# DVH list processing (default dose.units is "cGy")
plot(janedoe)
plot(LQE(janedoe,aB=3,fractions=200),col="red",new=FALSE)

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

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Type 'demo()' for some demos, 'help()' for on-line help, or
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> library(RadOnc)
Loading required package: rgl
Loading required package: geometry
Loading required package: magic
Loading required package: abind
Loading required package: oro.dicom

oro.dicom: Rigorous - DICOM Input / Output (version = 0.5.0)

Loading required package: ptinpoly
Loading required package: misc3d
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/RadOnc/LQE.Rd_%03d_medium.png", width=480, height=480)
> ### Name: LQE
> ### Title: Linear Quadratic Extrapolated (LQE) Dose Conversion
> ### Aliases: LQE LQE-methods LQE,ANY,missing-method
> ###   LQE,DVH.list,numeric-method LQE,DVH,numeric-method
> ###   LQE,numeric,numeric-method
> ### Keywords: methods manip
> 
> ### ** Examples
> 
> # 5x 300cGy == 9x 200cGy (1800cGy isoeffective dose)
> LQE(1500, aB=3, fractions=c(300, 200), dose.units="cGy")
[1] 1800
> LQE(15, aB=3, N=c(5, 9), dose.units="Gy")
[1] 18
> LQE(18, aB=3, fractions=c(2, 3), dose.units="Gy")
[1] 15
> 
> # Multiple simultaneous numerical queries
> LQE(c(4500, 5400), aB=3, fractions=c(300, 200), dose.units="cGy")
[1] 5400 6480
> 
> # DVH processing
> LQE(janedoe[["LIVER"]],aB=3,fractions=200,dose.units="cGy")
[1] "Structure: LIVER (1635.9cc), Dose: 42.72-5862.84cGy (5720cGy prescribed), DVH: cumulative, Volume: relative"
> 
> # DVH list processing (default dose.units is "cGy")
> plot(janedoe)
> plot(LQE(janedoe,aB=3,fractions=200),col="red",new=FALSE)
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>