The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform

Luc Beaulieu - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of an electron Monte Carlo dose calculation algorithm for treatment planning
    Journal of Applied Clinical Medical Physics, 2015
    Co-Authors: E Chamberland, Luc Beaulieu, B. Lachance
    Abstract:

    The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system’s behavior in simple geometries and in configurations encountered in clinical practice. The first series of tests were executed in a homogeneous water phantom, where experimental measurements and eMC-calculated dose distributions were compared for various combinations of energy and applicator. More specifically, we compared beam profiles and depth-dose curves at different source-to-surface distances (SSDs) and gantry angles, by using dose difference and distance to agreement. Also, we compared output factors, we studied the effects of algorithm input parameters, which are the random number generator seed, as well as the calculation grid size, and we performed a calculation time evaluation. Three different inhomogeneous solid phantoms were built, using high- and low-density materials inserts, to clinically simulate relevant heterogeneity conditions: a small air cylinder within a homogeneous phantom, a lung phantom, and a chest wall phantom. We also used an anthropomorphic phantom to perform comparison of eMC calculations to measurements. Finally, we proceeded with an evaluation of the eMC algorithm on a clinical case of Nose Cancer. In all mentioned cases, measurements, carried out by means of XV-2 films, radiographic films or EBT2 Gafchromic films. were used to compare eMC calculations with dose distributions obtained from an electron pencil beam algorithm. eMC calculations in the water phantom were accurate. Discrepancies for depth-dose curves and beam profiles were under 2.5% and 2 mm. Dose calculations with eMC for the small air cylinder and the lung phantom agreed within 2% and 4%, respectively. eMC calculations for the chest wall phantom and the anthropomorphic phantom also showed a positive agreement with the measurements. The retrospective dosimetric comparison of a clinical case, which presented scatter perturbations by air cavities, showed a difference in dose of up to 20% between pencil beam and eMC algorithms. When comparing to the pencil beam algorithm, eMC calculations are definitely more accurate at predicting large dose perturbations due to inhomogeneities.

  • Poster — Thur Eve — 12: Evaluation of an Electron Monte Carlo Dose Calculation Algorithm for Treatment Planning
    Medical Physics, 2010
    Co-Authors: E Chamberland, B. Lachance, Luc Beaulieu
    Abstract:

    Purpose: To evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in the Eclipse treatment planning system. Method and Materials: Multiple tests were planned to explore the system behaviour in configurations encountered in clinical practices. The first series of test were performed in a homogeneous water phantom. Measured and eMC calculated dose distributions were compared for different combinations of energy/applicator/depth. Three different inhomogeneous solid phantoms simulating high and low density materials were constructed to explore various heterogeneity conditions: a small air cylinder, a lung phantom and a chest wall phantom. In this work, the lung phantom, which consists of cork slabs, is described in details. In all cases, comparisons are made between measurements, carried out by means of XV‐2 films, and eMC and Pinnacle computations. Finally, the evaluation of the eMC algorithm for clinical case, a Nose Cancer, was conducted. Results: The eMC validation in the water phantom and in the lung phantom is shown to be accurate. The maximum observed discrepancy between measurements and eMC is only 2.5%. For the lung case, Pinnacle does not correctly model the electron scattering. The retrospective study of the clinical case, which presents scatter perturbations by air cavities, shows planar dose difference up to 20% between Pinnacle and eMC. Conclusion: eMC algorithm showed good agreements with measurements in simple homogeneous and heterogeneous phantoms. Comparatively to the electron pencil beam algorithms of Pinnacle, the eMC calculations more precisely predict large dose perturbations due to inhomogeneities.

  • SU‐GG‐T‐417: Evaluation of a Commercial Monte Carlo Dose Calculation Algorithm for Electron Beam Treatment Planning
    Medical Physics, 2010
    Co-Authors: E Chamberland, B. Lachance, Luc Beaulieu
    Abstract:

    Purpose: To evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in the Eclipse treatment planning system. Method and Materials: Multiple tests were planned to explore the system behaviour in configurations encountered in clinical practices. The first series of test were performed in a homogeneous water phantom. Measured and eMC calculated dose distributions were compared for different combinations of energy/applicator/depth. Three different inhomogeneous solid phantoms simulating high and low density materials were constructed to explore various heterogeneity conditions; a small air cylinder, a lung phantom and a chest wall phantom. The test under study is the lung inhomogeneity which consists of cork slabs. In all cases, comparisons are made between measurements, carried out by means of XV‐2 films, and eMC and Pinnacle computations. Finally, the evaluation of the eMC algorithm for a clinical case, a Nose Cancer, was conducted. Results: The eMC validation in the water phantom and in the lung phantom is shown to be accurate. The maximum observed discrepancy between measurements and eMC is 2.5%. For the lung case, Pinnacle does not correctly model the electron scattering. The retrospective study of the clinical case, which presents scatter perturbations by air cavities, shows planar dose difference up to 20% between Pinnacle and eMC. Conclusion: eMC algorithm showed good agreements with measurements in simple homogeneous and heterogeneous phantoms. Comparatively to the electron pencil beam algorithms of Pinnacle, the eMC calculations more precisely predict large dose perturbations due to inhomonegenities.

E Chamberland - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of an electron Monte Carlo dose calculation algorithm for treatment planning
    Journal of Applied Clinical Medical Physics, 2015
    Co-Authors: E Chamberland, Luc Beaulieu, B. Lachance
    Abstract:

    The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system’s behavior in simple geometries and in configurations encountered in clinical practice. The first series of tests were executed in a homogeneous water phantom, where experimental measurements and eMC-calculated dose distributions were compared for various combinations of energy and applicator. More specifically, we compared beam profiles and depth-dose curves at different source-to-surface distances (SSDs) and gantry angles, by using dose difference and distance to agreement. Also, we compared output factors, we studied the effects of algorithm input parameters, which are the random number generator seed, as well as the calculation grid size, and we performed a calculation time evaluation. Three different inhomogeneous solid phantoms were built, using high- and low-density materials inserts, to clinically simulate relevant heterogeneity conditions: a small air cylinder within a homogeneous phantom, a lung phantom, and a chest wall phantom. We also used an anthropomorphic phantom to perform comparison of eMC calculations to measurements. Finally, we proceeded with an evaluation of the eMC algorithm on a clinical case of Nose Cancer. In all mentioned cases, measurements, carried out by means of XV-2 films, radiographic films or EBT2 Gafchromic films. were used to compare eMC calculations with dose distributions obtained from an electron pencil beam algorithm. eMC calculations in the water phantom were accurate. Discrepancies for depth-dose curves and beam profiles were under 2.5% and 2 mm. Dose calculations with eMC for the small air cylinder and the lung phantom agreed within 2% and 4%, respectively. eMC calculations for the chest wall phantom and the anthropomorphic phantom also showed a positive agreement with the measurements. The retrospective dosimetric comparison of a clinical case, which presented scatter perturbations by air cavities, showed a difference in dose of up to 20% between pencil beam and eMC algorithms. When comparing to the pencil beam algorithm, eMC calculations are definitely more accurate at predicting large dose perturbations due to inhomogeneities.

  • Poster — Thur Eve — 12: Evaluation of an Electron Monte Carlo Dose Calculation Algorithm for Treatment Planning
    Medical Physics, 2010
    Co-Authors: E Chamberland, B. Lachance, Luc Beaulieu
    Abstract:

    Purpose: To evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in the Eclipse treatment planning system. Method and Materials: Multiple tests were planned to explore the system behaviour in configurations encountered in clinical practices. The first series of test were performed in a homogeneous water phantom. Measured and eMC calculated dose distributions were compared for different combinations of energy/applicator/depth. Three different inhomogeneous solid phantoms simulating high and low density materials were constructed to explore various heterogeneity conditions: a small air cylinder, a lung phantom and a chest wall phantom. In this work, the lung phantom, which consists of cork slabs, is described in details. In all cases, comparisons are made between measurements, carried out by means of XV‐2 films, and eMC and Pinnacle computations. Finally, the evaluation of the eMC algorithm for clinical case, a Nose Cancer, was conducted. Results: The eMC validation in the water phantom and in the lung phantom is shown to be accurate. The maximum observed discrepancy between measurements and eMC is only 2.5%. For the lung case, Pinnacle does not correctly model the electron scattering. The retrospective study of the clinical case, which presents scatter perturbations by air cavities, shows planar dose difference up to 20% between Pinnacle and eMC. Conclusion: eMC algorithm showed good agreements with measurements in simple homogeneous and heterogeneous phantoms. Comparatively to the electron pencil beam algorithms of Pinnacle, the eMC calculations more precisely predict large dose perturbations due to inhomogeneities.

  • SU‐GG‐T‐417: Evaluation of a Commercial Monte Carlo Dose Calculation Algorithm for Electron Beam Treatment Planning
    Medical Physics, 2010
    Co-Authors: E Chamberland, B. Lachance, Luc Beaulieu
    Abstract:

    Purpose: To evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in the Eclipse treatment planning system. Method and Materials: Multiple tests were planned to explore the system behaviour in configurations encountered in clinical practices. The first series of test were performed in a homogeneous water phantom. Measured and eMC calculated dose distributions were compared for different combinations of energy/applicator/depth. Three different inhomogeneous solid phantoms simulating high and low density materials were constructed to explore various heterogeneity conditions; a small air cylinder, a lung phantom and a chest wall phantom. The test under study is the lung inhomogeneity which consists of cork slabs. In all cases, comparisons are made between measurements, carried out by means of XV‐2 films, and eMC and Pinnacle computations. Finally, the evaluation of the eMC algorithm for a clinical case, a Nose Cancer, was conducted. Results: The eMC validation in the water phantom and in the lung phantom is shown to be accurate. The maximum observed discrepancy between measurements and eMC is 2.5%. For the lung case, Pinnacle does not correctly model the electron scattering. The retrospective study of the clinical case, which presents scatter perturbations by air cavities, shows planar dose difference up to 20% between Pinnacle and eMC. Conclusion: eMC algorithm showed good agreements with measurements in simple homogeneous and heterogeneous phantoms. Comparatively to the electron pencil beam algorithms of Pinnacle, the eMC calculations more precisely predict large dose perturbations due to inhomonegenities.

B. Lachance - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of an electron Monte Carlo dose calculation algorithm for treatment planning
    Journal of Applied Clinical Medical Physics, 2015
    Co-Authors: E Chamberland, Luc Beaulieu, B. Lachance
    Abstract:

    The purpose of this study is to evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in a commercial treatment planning system and compare its performance against an electron pencil beam algorithm. Several tests were performed to explore the system’s behavior in simple geometries and in configurations encountered in clinical practice. The first series of tests were executed in a homogeneous water phantom, where experimental measurements and eMC-calculated dose distributions were compared for various combinations of energy and applicator. More specifically, we compared beam profiles and depth-dose curves at different source-to-surface distances (SSDs) and gantry angles, by using dose difference and distance to agreement. Also, we compared output factors, we studied the effects of algorithm input parameters, which are the random number generator seed, as well as the calculation grid size, and we performed a calculation time evaluation. Three different inhomogeneous solid phantoms were built, using high- and low-density materials inserts, to clinically simulate relevant heterogeneity conditions: a small air cylinder within a homogeneous phantom, a lung phantom, and a chest wall phantom. We also used an anthropomorphic phantom to perform comparison of eMC calculations to measurements. Finally, we proceeded with an evaluation of the eMC algorithm on a clinical case of Nose Cancer. In all mentioned cases, measurements, carried out by means of XV-2 films, radiographic films or EBT2 Gafchromic films. were used to compare eMC calculations with dose distributions obtained from an electron pencil beam algorithm. eMC calculations in the water phantom were accurate. Discrepancies for depth-dose curves and beam profiles were under 2.5% and 2 mm. Dose calculations with eMC for the small air cylinder and the lung phantom agreed within 2% and 4%, respectively. eMC calculations for the chest wall phantom and the anthropomorphic phantom also showed a positive agreement with the measurements. The retrospective dosimetric comparison of a clinical case, which presented scatter perturbations by air cavities, showed a difference in dose of up to 20% between pencil beam and eMC algorithms. When comparing to the pencil beam algorithm, eMC calculations are definitely more accurate at predicting large dose perturbations due to inhomogeneities.

  • Poster — Thur Eve — 12: Evaluation of an Electron Monte Carlo Dose Calculation Algorithm for Treatment Planning
    Medical Physics, 2010
    Co-Authors: E Chamberland, B. Lachance, Luc Beaulieu
    Abstract:

    Purpose: To evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in the Eclipse treatment planning system. Method and Materials: Multiple tests were planned to explore the system behaviour in configurations encountered in clinical practices. The first series of test were performed in a homogeneous water phantom. Measured and eMC calculated dose distributions were compared for different combinations of energy/applicator/depth. Three different inhomogeneous solid phantoms simulating high and low density materials were constructed to explore various heterogeneity conditions: a small air cylinder, a lung phantom and a chest wall phantom. In this work, the lung phantom, which consists of cork slabs, is described in details. In all cases, comparisons are made between measurements, carried out by means of XV‐2 films, and eMC and Pinnacle computations. Finally, the evaluation of the eMC algorithm for clinical case, a Nose Cancer, was conducted. Results: The eMC validation in the water phantom and in the lung phantom is shown to be accurate. The maximum observed discrepancy between measurements and eMC is only 2.5%. For the lung case, Pinnacle does not correctly model the electron scattering. The retrospective study of the clinical case, which presents scatter perturbations by air cavities, shows planar dose difference up to 20% between Pinnacle and eMC. Conclusion: eMC algorithm showed good agreements with measurements in simple homogeneous and heterogeneous phantoms. Comparatively to the electron pencil beam algorithms of Pinnacle, the eMC calculations more precisely predict large dose perturbations due to inhomogeneities.

  • SU‐GG‐T‐417: Evaluation of a Commercial Monte Carlo Dose Calculation Algorithm for Electron Beam Treatment Planning
    Medical Physics, 2010
    Co-Authors: E Chamberland, B. Lachance, Luc Beaulieu
    Abstract:

    Purpose: To evaluate the accuracy of the electron Monte Carlo (eMC) dose calculation algorithm included in the Eclipse treatment planning system. Method and Materials: Multiple tests were planned to explore the system behaviour in configurations encountered in clinical practices. The first series of test were performed in a homogeneous water phantom. Measured and eMC calculated dose distributions were compared for different combinations of energy/applicator/depth. Three different inhomogeneous solid phantoms simulating high and low density materials were constructed to explore various heterogeneity conditions; a small air cylinder, a lung phantom and a chest wall phantom. The test under study is the lung inhomogeneity which consists of cork slabs. In all cases, comparisons are made between measurements, carried out by means of XV‐2 films, and eMC and Pinnacle computations. Finally, the evaluation of the eMC algorithm for a clinical case, a Nose Cancer, was conducted. Results: The eMC validation in the water phantom and in the lung phantom is shown to be accurate. The maximum observed discrepancy between measurements and eMC is 2.5%. For the lung case, Pinnacle does not correctly model the electron scattering. The retrospective study of the clinical case, which presents scatter perturbations by air cavities, shows planar dose difference up to 20% between Pinnacle and eMC. Conclusion: eMC algorithm showed good agreements with measurements in simple homogeneous and heterogeneous phantoms. Comparatively to the electron pencil beam algorithms of Pinnacle, the eMC calculations more precisely predict large dose perturbations due to inhomonegenities.

Lewandowski L - One of the best experts on this subject based on the ideXlab platform.

Conrad P. Sprunger - One of the best experts on this subject based on the ideXlab platform.

  • Accuracy of pencil‐beam redefinition algorithm dose calculations in patient‐like cylindrical phantoms for bolus electron conformal therapy
    Medical Physics, 2013
    Co-Authors: Robert L. Carver, Kenneth R. Hogstrom, Robert S. Fields, Conrad P. Sprunger
    Abstract:

    Purpose: The purpose of this study was to document the improved accuracy of the pencil beam redefinition algorithm (PBRA) compared to the pencil beam algorithm (PBA) for bolus electron conformal therapy using cylindrical patient phantoms based on patient computed tomography (CT) scans of retromolar trigone and Nose Cancer. Methods: PBRA and PBA electron dose calculations were compared with measured dose in retromolar trigone and Nose phantoms both with and without bolus. For the bolus treatment plans, a radiation oncologist outlined a planning target volume (PTV) on the central axis slice of the CT scan for each phantom. A bolus was designed using the planning.decimal® (p.d) software (.decimal, Inc., Sanford, FL) to conform the 90% dose line to the distal surface of the PTV. Dose measurements were taken with thermoluminescent dosimeters placed into predrilled holes. The Pinnacle3 (Philips Healthcare, Andover, MD) treatment planning system was used to calculate PBA dose distributions. The PBRA dose distributions were calculated with an in-house C++ program. In order to accurately account for the phantom materials a table correlating CT number to relative electron stopping and scattering powers was compiled and used for both PBA and PBRA dose calculations. Accuracy was determined by comparing differences in measured and calculated dose, as well as distance to agreement for each measurement point. Results: The measured doses had an average precision of 0.9%. For the retromolar trigone phantom, the PBRA dose calculations had an average ±1σ dose difference (calculated − measured) of −0.65% ± 1.62% without the bolus and −0.20% ± 1.54% with the bolus. The PBA dose calculation had an average dose difference of 0.19% ± 3.27% without the bolus and −0.05% ± 3.14% with the bolus. For the Nose phantom, the PBRA dose calculations had an average dose difference of 0.50% ± 3.06% without bolus and −0.18% ± 1.22% with the bolus. The PBA dose calculations had an average dose difference of 0.65% ± 6.21% without bolus and 1.75% ± 5.94% with the bolus. From a clinical perspective an agreement of 5% or better between planned (calculated) and delivered (measured) dose is desired. Statistically, this was true for 99% (±2σ) of the dose points for three of the four cases for the PBRA dose calculations, the exception being the Nose without bolus for which this was true for 89% (±1.6σ) of the dose points. For the retromolar trigone, with and without bolus, the PBA showed agreement of 5% or better for approximately 86% (±1.5σ) of the dose points. For the Nose, with and without bolus, the PBA showed agreement of 5% or better for only approximately 58% (±0.8σ) of the dose points. Conclusions: The measured data, whose high precision makes them useful for evaluation of the accuracy of electron dose algorithms, will be made publicly available. Based on the spread in dose differences, the PBRA has at least twice the accuracy of the PBA. From a clinical perspective the PBRA accuracy is acceptable in the retromolar trigone and Nose for electron therapy with and without bolus.