An overview of Monte Carlo treatment planning for radiotherapy

Spezi, Emiliano; Lewis, Geraint

doi:10.1093/rpd/ncn277

Cited by 49 publications

(31 citation statements)

References 23 publications

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“…Many radiation therapy techniques have been developed based on this principle, and among them, intensity modulated radiation therapy (IMRT) has been considered one of the most exciting developments since the introduction of computed tomography imaging into treatment planning [2][3][4]. Monte Carlo (MC) simulations are widely used in ra-diation therapy research, from micro dosimetry at the cell level to radiation shielding design [5,6]. Specifically, the MC algorithm is considered to be the most accurate way to calculate the dose in heterogeneous media, such as bone, soft tissue, muscle, and other tissues found in patients [7].…”

Section: Introductionmentioning

confidence: 99%

Feasibility of using Geant4 Monte Carlo simulation for IMRT dose calculations for the Novalis Tx with a HD-120 multi-leaf collimator

Jung

Shin

Chung

et al. 2015

Journal of the Korean Physical Society

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The aim of this study was to develop an independent dose verification system by using a Monte Carlo (MC) calculation method for intensity modulated radiation therapy (IMRT) conducted by using a Varian Novalis Tx (Varian Medical Systems, Palo Alto, CA, USA) equipped with a highdefinition multi-leaf collimator (HD-120 MLC). The Geant4 framework was used to implement a dose calculation system that accurately predicted the delivered dose. For this purpose, the Novalis Tx Linac head was modeled according to the specifications acquired from the manufacturer. Subsequently, MC simulations were performed by varying the mean energy, energy spread, and electron spot radius to determine optimum values of irradiation with 6-MV X-ray beams by using the Novalis Tx system. Computed percentage depth dose curves (PDDs) and lateral profiles were compared to the measurements obtained by using an ionization chamber (CC13). To validate the IMRT simulation by using the MC model we developed, we calculated a simple IMRT field and compared the result with the EBT3 film measurements in a water-equivalent solid phantom. Clinical cases, such as prostate cancer treatment plans, were then selected, and MC simulations were performed. The accuracy of the simulation was assessed against the EBT3 film measurements by using a gamma-index criterion. The optimal MC model parameters to specify the beam characteristics were a 6.8-MeV mean energy, a 0.5-MeV energy spread, and a 3-mm electron radius. The accuracy of these parameters was determined by comparison of MC simulations with measurements. The PDDs and the lateral profiles of the MC simulation deviated from the measurements by 1% and 2%, respectively, on average. The computed simple MLC fields agreed with the EBT3 measurements with a 95% passing rate with 3%/3-mm gamma-index criterion. Additionally, in applying our model to clinical IMRT plans, we found that the MC calculations and the EBT3 measurements agreed well with a passing rate of greater than 95% on average with a 3%/3-mm gamma-index criterion. In summary, the Novalis Tx Linac head equipped with a HD-120 MLC was successfully modeled by using a Geant4 platform, and the accuracy of the Geant4 platform was successfully validated by comparisons with measurements. The MC model we have developed can be a useful tool for pretreatment quality assurance of IMRT plans and for commissioning of radiotherapy treatment planning.

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Section: Introductionmentioning

confidence: 99%

Feasibility of using Geant4 Monte Carlo simulation for IMRT dose calculations for the Novalis Tx with a HD-120 multi-leaf collimator

Jung

Shin

Chung

et al. 2015

Journal of the Korean Physical Society

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“…MC in the macrodosimetric region has been in use for over 50 years, and codes like MCNPX, PENELOPE, BEAM and GEANT4 have been used to simulate the physics interactions in matter on a millimeter scale [1,2,19,21,22]. Treatment planning systems are also being developed that use the MC method, and the American Association of Physicists in Medicine (AAPM) has a task group report on the subject [4,27].…”

Section: Introductionmentioning

confidence: 99%

The effect of energy spectrum change on DNA damage in and out of field in 10-MV clinical photon beams

Ezzati

Xiao

Sohrabpour

et al. 2014

Med Biol Eng Comput

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The aim of this study was to quantify the DNA damage induced in a clinical megavoltage photon beam at various depths in and out of the field. MCNPX was used to simulate 10 × 10 and 20 × 20 cm(2) 10-MV photon beams from a clinical linear accelerator. Photon and electron spectra were collected in a water phantom at depths of 2.5, 12.5 and 22.5 cm on the central axis and at off-axis points out to 10 cm. These spectra were used as an input to a validated microdosimetric Monte Carlo code, MCDS, to calculate the RBE of induced DSB in DNA at points in and out of the primary radiation field at three depths. There was an observable difference in the energy spectra for photons and electrons for points in the primary radiation field and those points out of field. In the out-of-field region, the mean energy for the photon and electron spectra decreased by a factor of about six and three from the in-field mean energy, respectively. Despite the differences in spectra and mean energy, the change in RBE was <1 % from the in-field region to the out-of-field region at any depth. There was no significant change in RBE regardless of the location in the phantom. Although there are differences in both the photon and electron spectra, these changes do not correlate with a change in RBE in a clinical MV photon beam as the electron spectra are dominated by electrons with energies >20 keV.

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“…1,2 The EGSnrc Monte Carlo package features validated models of particle ͑photon, electron, and positron͒ interactions and is a widely accepted standard for photonelectron transport. 3 The EGSnrc package only implements particle transport through matter. User codes are required to implement comprehensive simulations including particle sources and propagation geometries.…”

Section: Introductionmentioning

confidence: 99%

Epp: A C++ EGSnrc user code for x‐ray imaging and scattering simulations

et al. 2011

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Epp provides the user with useful features, including the ability to build complex geometries from simpler ones and the ability to generate images of scattered and primary photons. There is no inherent computational time saving arising from Epp, except for those arising from egspp's ability to use analytical representations of simulation geometries. Epp agrees with DOSXYZnrc in dose calculation, since they are both based on the well-validated standard EGSnrc radiation transport physics model.

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An overview of Monte Carlo treatment planning for radiotherapy

Cited by 49 publications

References 23 publications

Feasibility of using Geant4 Monte Carlo simulation for IMRT dose calculations for the Novalis Tx with a HD-120 multi-leaf collimator

Feasibility of using Geant4 Monte Carlo simulation for IMRT dose calculations for the Novalis Tx with a HD-120 multi-leaf collimator

The effect of energy spectrum change on DNA damage in and out of field in 10-MV clinical photon beams

Epp: A C++ EGSnrc user code for x‐ray imaging and scattering simulations

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