scholarly journals A Review on the Use of Grid-Based Boltzmann Equation Solvers for Dose Calculation in External Photon Beam Treatment Planning

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Monica W. K. Kan ◽  
Peter K. N. Yu ◽  
Lucullus H. T. Leung
Keyword(s):  
Treatment Planning ◽  
Heterogeneous Media ◽  
Dose Calculation ◽  
Photon Beam ◽  
Planning System ◽  
Treatment Planning System ◽  
Boltzmann Transport ◽  
Accurate Dose ◽  
Software Codes ◽  
Beam Dose

Deterministic linear Boltzmann transport equation (D-LBTE) solvers have recently been developed, and one of the latest available software codes, Acuros XB, has been implemented in a commercial treatment planning system for radiotherapy photon beam dose calculation. One of the major limitations of most commercially available model-based algorithms for photon dose calculation is the ability to account for the effect of electron transport. This induces some errors in patient dose calculations, especially near heterogeneous interfaces between low and high density media such as tissue/lung interfaces. D-LBTE solvers have a high potential of producing accurate dose distributions in and near heterogeneous media in the human body. Extensive previous investigations have proved that D-LBTE solvers were able to produce comparable dose calculation accuracy as Monte Carlo methods with a reasonable speed good enough for clinical use. The current paper reviews the dosimetric evaluations of D-LBTE solvers for external beam photon radiotherapy. This content summarizes and discusses dosimetric validations for D-LBTE solvers in both homogeneous and heterogeneous media under different circumstances and also the clinical impact on various diseases due to the conversion of dose calculation from a conventional convolution/superposition algorithm to a recently released D-LBTE solver.

scholarly journals Dosimetric Evaluation of a Treatment Planning System Using the Aapm Medical Physics Practice Guideline 5.a (MPPG 5.a) Validation Tests

2021 ◽  
Author(s):  
Yousif A Yousif ◽  
Jackson Zifodya
Keyword(s):  
Treatment Planning ◽  
Practice Guideline ◽  
Heterogeneous Media ◽  
Medical Physics ◽  
Dose Calculation ◽  
Pass Rate ◽  
Planning System ◽  
Treatment Planning System ◽  
Mean Deviation ◽  
Validation Tests

Abstract In this work, the AAPM Medical Physics Practice Guideline 5.a (MPPG 5.a) validation tests package was used to evaluate the dosimetric performance of a new version of the Eclipse treatment planning system (TPS) algorithms. A series of tests were developed and comparisons between TPS calculated and corresponding beam data measurements have been performed for basic beam validation, heterogeneity correction and IMRT/VMAT dose validation tests. Measurements were performed using a Varian IX Linear Accelerator with the 6 MV, 6MV FFF and 18 MV photon beams, and 6, 9, 12, 16, 20 MeV electron beams. Results for basic dose validation tests yielded differences within 3% for all point doses and pass rate greater than 95% for all depth profiles using 3%/3mm criteria. For testing the ability of the TPS in accounting for tissue inhomogeneity, corresponding comparisons were performed with the presence of a heterogeneous media to simulate an air inhomogeneity. Results showed a mean deviation between the TPS calculated and measured of 1.9%, reaching a maximum of 2.8% for the AAA algorithm. For IMRT/VMAT validation tests, our local criteria passing rate of 95% was used, but no consensus of the tolerance exists. Our results agree well with the data reported accuracy in previous studies of Eclipse TPS. In summary, the AAPM MPPG 5.a validation tests are a valuable package for evaluating dose calculation accuracy and are very useful for TPS upgrade checks, commissioning tests and routine TPS QA.

scholarly journals Dosimetric Study of Breast Scar Marker in Different Radiotherapy Dose Calculation Algorithms

2019 ◽  
Author(s):  
S. S Abdullah ◽  
Ahmed Alsadig ◽  
A. Sulieman ◽  
Isam H. Mattar ◽  
C. K. Ying ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Scar Marker ◽  
Dose Calculation ◽  
Photon Beam ◽  
Radiochromic Film ◽  
Planning System ◽  
Treatment Planning System ◽  
Collapsed Cone ◽  
Ct Simulation ◽  
Dose Calculation Algorithms

AbstractThe purpose to this work is to validate and benchmark the delivered dose accuracy during radiotherapy treatment (without marker at scar site) to the dose calculated by treatment planning that included a marker on scar site. Dose distributions in breast cancer 3-dimensional conformal treatment planning (3D CRT) calculated with Pencil Beam (PB) and Collapsed Cone (CC) algorithms of commercial treatment planning system (Monaco and Oncentra MasterPlan) was compared as photon beam through homogenous and heterogenous media (by placing marker on phantom surface) to evaluate the perturbation of photon beam. Radiochromic film dose distribution value was compared to the dose calculated by CC algorithm of Monaco and Oncentra MasterPlan (OMP) Treatment Planning Systems (TPS) and PB algorithm of OMP TPS. During Computed Tomography (CT) simulation procedure for breast case, a metal-based scar marker (wire) was used to localize the tumour bed during treatment planning procedure which the phantom was considered as heterogeneous medium. In homogenous medium, PB algorithm gave smaller dose deviation compared to CC algorithm. When wire was introduced to the surface of phantom, PB algorithm (6.0 cGy) gave higher dose deviation compared to CC algorithm (2.0 cGy). However, CC algorithm (plasticine: 7.0 cGy and cable: 7.3 cGy) shows higher dose deviation compared to PB algorithm (plasticine: 6.3 cGy and cable: 6.6 cGy) when Plasticine and Cable marker were introduced. The placement of marker in lateral orientation gave smaller perturbation to megavoltage photon beam compared to axial orientation in overall case. Moreover, wire and plasticine are suitable as a scar marker due to its tissue equivalent density with less perturbation to photon beam.

Sign in / Sign up

Export Citation Format

Share Document