A new DOSXYZnrc method for Monte Carlo simulations of 4D dose distributions

Abstract The purpose of this study is to present a novel method for generating Monte Carlo 4D dose distributions in a single DOSXYZnrc simulation. During a standard simulation, individual energy deposition events are summed up to generate a 3D dose distribution and their associated temporal information is discarded. This means that in order to determine dose distributions as a function of time, separate simulations would have to be run for each interval of interest. Consequently, it has not been clinically feasible until now to routinely perform Monte Carlo simulations of dose rate, time-resolved dose accumulation, or EPID cine-mode images for VMAT plans. To overcome this limitation, we modified DOSXYZnrc and defined new input and output variables that allow a time-like parameter associated with each particle history to be binned in a user-defined manner. Under the new code version, computation times are the same as for a standard simulation, and the time-integrated 4D dose is identical to the standard 3D dose. We present a comparison of scintillator measurements and Monte Carlo simulations for dose rate during a VMAT beam delivery, a study of dose rate in a VMAT Total Body Irradiation plan, and simulations of transit (through-patient) EPID cine-mode images.

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Poster - Thur Eve - 55: Monte Carlo simulations of variations in planned dose distributions in a prostate patient population

Medical Physics ◽

10.1118/1.4740163 ◽

2012 ◽

Vol 39 (7Part3) ◽

pp. 4635-4635

Author(s):

MJ Balderson ◽

DW Brown ◽

S Quirk ◽

E Ghasroddashti ◽

C Kirkby

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Patient Population ◽

Dose Distributions

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Evaluation of dose-volume metrics for microbeam radiation therapy dose distributions in head phantoms of various sizes using Monte Carlo simulations

Physics in Medicine and Biology ◽

10.1088/0031-9155/57/10/3223 ◽

2012 ◽

Vol 57 (10) ◽

pp. 3223-3248 ◽

Cited By ~ 8

Author(s):

Danielle Anderson ◽

E Albert Siegbahn ◽

B Gino Fallone ◽

Raphael Serduc ◽

Brad Warkentin

Keyword(s):

Monte Carlo ◽

Radiation Therapy ◽

Monte Carlo Simulations ◽

Dose Distributions ◽

Microbeam Radiation Therapy ◽

Dose Volume

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Field gamma spectrometry, Monte Carlo simulations and potential of non-invasive measurements

Geochronometria ◽

10.2478/s13386-011-0056-z ◽

2012 ◽

Vol 39 (1) ◽

pp. 40-47 ◽

Cited By ~ 6

Author(s):

Guillaume Guérin ◽

Norbert Mercier

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Dose Rate ◽

Gamma Dose ◽

Luminescence Dating ◽

Gamma Dose Rate ◽

Invasive Technique ◽

Simple Method ◽

Dose Rates ◽

Non Invasive

Abstract The determination of gamma dose rates is of prior importance in the field of luminescence dating methods. In situ measurements are usually performed by the insertion of dosimeters or a portable gamma spectrometer cell in sediments. In this paper, Monte-Carlo simulations using the Geant4 toolkit allow the development of a new technique of insitu gamma dose rate evaluations: a spectrometer cell is placed on the surface of sediments under excavation to acquire successive spectra as sediments are removed by excavations. The principle of this non-invasive technique is outlined and its potential is discussed, especially in the case of environments in which radioelements are heterogeneously distributed. For such cases, a simple method to reconstruct gamma dose rate values with surface measurements using an attenuator is discussed, and an estimation of errors is given for two simple cases. This technique appears to be applicable, but still needs experimental validation.

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