RADIATION DOSIMETRY AND CALIBRATION

About : Computation of absorbed dose to water and dose calibration using GUI application.

To run the application open calibration.fig

FILE CONTENTS

• Calibration.m : Main function.

• Calibration.fig : Calibration Gui.

• BeamQual.m : Correction for the user beam quality. Collects and stores data for the beam quality at the corresponding HVL value.

• BeamQual.fig : Beam quality data Gui

• DetRespData.m : Collects data for the ionization chamber response (Air-Kerma) with time (sec). Important: Please use the corrected dose values here as the detector response. The End effect correction must be applied only after the correction calculations have been performed.

• DetRespData.fig : Detector response data Gui.

• EndEffLinRegr.m : Performs linear regression on the detector response data.

• Error.m : Generates the error statements throughout the program.

• Error.fig : Error statement Gui.

• KqViewGraph.m : Performs extrapolation and interpolation on the beam quality data.

• KqViewGraph.fig : Shows the piecewice cubic polynomial fit of the beam quality data.

• LinRegr.m : Performs linear regression to find the ion recombination correction factor.

• MminusMeasurement.m : Function to collect and store the negative polarity measurements from the ionization chamber.

• MminusMeasurement.fig : Gui to collect and store the negative polarity measurements from the ionization chamber.

• MplusMeasurement.m : Function to collect and store the positive polarity measurements from the ionization chamber.

• MplusMeasurement.fig : Gui to collect and store the positive polarity measurements from the ionization chamber.

• Pressure.m : Function to collect and store the pressure values at the test location.

• Pressure.fig : Gui to collect and store the pressure values at the test location.

• SaveFile.m : Function to save the entered and calculated data from the Calibration Gui.

• SaveFile.fig : Gui to save the entered and calculated data from the Calibration Gui.

• Temp.m : Function to collect and store the pressure values at the test location.

• Temp.fig : Gui to collect and store the pressure values at the test location.

• ValueSet.m : ValueSet1, ValueSet2, ValueSet3 and ValueSet4 collects the current measurements (M+ and M-) at a selected electrometer voltage.

• ViewGraph.m : This function executes the LinRegr.m to perform linear regression on the ValueSet data and produces the regression statistics.

• ViewGraph.fig : Gui to shows the linear regression results of the ValueSet data and displays the regression statistics.

FILE CONTENTS IN SUB-FOLDER ../WaterToAirMeanMassEnergyAbsCoeff/

• DetectorEfficiency.m : Function to model the quantum efficiency of the photon counting detector.

• MMEACSaveFile.m : Function to save the entered and calculated data from the water to air mean mass energy absorption coefficient Gui.

• MMEACSaveFile.fig : Gui to save the entered and calculated data from the water to air mean mass energy absorption coefficient Gui.

• Note.m : Function to pass helping statements and suggestions.

• Note.fig : Gui to display helping statements and suggestions.

• The functions ParseChemicalFormula.m, PhotonAttenuation.m, PhotonAttenuationQ.m and PhysProps.m provide the attenuation and energy absorption of x-ray and gamma-ray photons in various materials including mixtures and compounds, based on NIST report 5632, by J. Hubbell and S.M. Seltzer.

• TotalEfficiency.m : Function to approximate the total efficiency of the photon counting detector by including the solid angle calculations.

• WaterToAirMeanMassEnergyAbsCoeff.m : Function to approximate the water to air mean mass energy absorption coefficient form the incident X-Ray spectra.

• WaterToAirMeanMassEnergyAbsCoeff.fig : Gui to to approximate the water to air mean mass energy absorption coefficient form the incident X-Ray spectra by loading the measured spectrum and getting the user data to approximate the detector properties.

References

• Andreo, Pedro, et al. "Absorbed dose determination in external beam radiotherapy: an international code of practice for dosimetry based on standards of absorbed dose to water." IAEA TRS 398 (2000).

• Chica, U., et al. "Quality indexes based on water measurements for low and medium energy x‐ray beams: A theoretical study with PENELOPE." Medical physics 41.1 (2014).

• Ma, C. M., and J. P. Seuntjens. "Mass-energy absorption coefficient and backscatter factor ratios for kilovoltage x-ray beams." Physics in Medicine & Biology 44.1 (1999): 131.

• Hill, Robin, et al. "An evaluation of ionization chambers for the relative dosimetry of kilovoltage x‐ray beams." Medical physics 36.9Part1 (2009): 3971-3981.

• Bruggmoser, G., et al. "Determination of the recombination correction factor kS for some specific plane-parallel and cylindrical ionization chambers in pulsed photon and electron beams." Physics in Medicine & Biology 52.2 (2006): N35.