The Experts below are selected from a list of 1773 Experts worldwide ranked by ideXlab platform
Ali S. Meigooni - One of the best experts on this subject based on the ideXlab platform.
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Developing a Treatment Planning Software Based on TG-43U1 Formalism for Cs-137 LDR Brachytherapy.
Iranian Red Crescent medical journal, 2013Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, Mohammad Amin Mosleh-shiraziAbstract:Background: The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in Treatment TPSs. Objectives: The purpose of this study is to design and establish a Treatment Planning Software for Cs-137 Solectron brachytherapy source, based on TG-43U1 formalism by applying the effects of the applicator and dummy spacers. Materials and Methods: Two Softwares used for Treatment Planning of Cs-137 sources in Iran (STPS and PLATO), are based on old formalisms. The purpose of this work is to establish and develop a TPS for Selectron source based on TG-43 formalism. In this Planning system, the dosimetry parameters of each pellet in different places inside applicators were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets was obtained by summing the doses. The accuracy of this algorithm was checked by comparing its results for special combination of active and inactive pellets with MC simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS and PLATO Softwares with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is about 30%, while the difference between the results of MCNP and the new algorithm is less than 5%. Conclusions: According to the results, the old dosimetry formalisms, overestimate the dose especially towards the applicator’s tip. While the TG-43U1 based Software perform the calculations more accurately.
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SU‐E‐T‐525: Developing a GYN Cs‐Selectron Brachytherapy Treatment Planning Software Accounting for Inter‐Source, Applicator and Heterogeneity Effects
Medical Physics, 2013Co-Authors: Habib Safigholi, Sedigheh Sina, Dariush Sardari, S Karimi Jashni, M Mosleh‐shirazi, S Karbasi, F Massicano, R Guedes Possoni, H Yoriyaz, Ali S. MeigooniAbstract:Purpose: In this project new Treatment Software based on TG‐43U1 and Monte Carlo (MC) simulations for Treatment of GYN cancers were developed. This Treatment Software accounted for inter‐source effect, applicator attenuation, and tissue heterogeneity for Cs‐137 selectron machine. Methods: MC Linear TG‐43U1 functions for combination of 8 active‐inactive pellets with 2 cm physical length for filling tandem and ovoid were obtained. Total length of tandem and ovoid filled with three and one linear sources, respectively. With this approach inter‐source effect and applicator attenuations have been hidden in TG‐43U1 functions. To account heterogeneity effect in Software design, the library of dose inhomogeneity correction factor (DICF) for various different thickness and position respect to one active Cs pellet for air and aluminum (as a bone) were simulated. A non‐homogen GYN polyethylene phantom were designed, which contain a cylinder of air as a rectum, and two symmetric aluminum spheres as a femur bone heads. GYN reference dosimetry points for TLD detectors were machined in the phantom according ICRU‐38 report. Finally reference points dose rate were compared using new Software, STPS Software, TLD measurements and full MC simulations. Results: New Software data have good agreement with TLD and MC simulations (up to 5%). However STPS data for more reference points are less than TLD and MC simulation (up to 3%) due to not considered applicators and inter‐source attenuation. For tip of tandem and ovoid STPS data are more than TLD, and MC about 26% and 17%, respectively. More over DICF data can create data with accuracy of 2% in comparison to TLD and MC measurements. Conclusion: In this project for first time developed a 3D GYN‐Cs‐Selectron Treatment Planning Software (TPS) based on Linear TG‐43U1 functions and libraries of MC simulations which modified inter‐source effect, applicator attenuations, and heterogeneity effects.
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su e t 525 developing a gyn cs selectron brachytherapy Treatment Planning Software accounting for inter source applicator and heterogeneity effects
Medical Physics, 2013Co-Authors: Habib Safigholi, M Moslehshirazi, Dariush Sardari, S Karbasi, F Massicano, H Yoriyaz, S Sina, Karimi S Jashni, Guedes R Possoni, Ali S. MeigooniAbstract:Purpose: In this project new Treatment Software based on TG‐43U1 and Monte Carlo (MC) simulations for Treatment of GYN cancers were developed. This Treatment Software accounted for inter‐source effect, applicator attenuation, and tissue heterogeneity for Cs‐137 selectron machine. Methods: MC Linear TG‐43U1 functions for combination of 8 active‐inactive pellets with 2 cm physical length for filling tandem and ovoid were obtained. Total length of tandem and ovoid filled with three and one linear sources, respectively. With this approach inter‐source effect and applicator attenuations have been hidden in TG‐43U1 functions. To account heterogeneity effect in Software design, the library of dose inhomogeneity correction factor (DICF) for various different thickness and position respect to one active Cs pellet for air and aluminum (as a bone) were simulated. A non‐homogen GYN polyethylene phantom were designed, which contain a cylinder of air as a rectum, and two symmetric aluminum spheres as a femur bone heads. GYN reference dosimetry points for TLD detectors were machined in the phantom according ICRU‐38 report. Finally reference points dose rate were compared using new Software, STPS Software, TLD measurements and full MC simulations. Results: New Software data have good agreement with TLD and MC simulations (up to 5%). However STPS data for more reference points are less than TLD and MC simulation (up to 3%) due to not considered applicators and inter‐source attenuation. For tip of tandem and ovoid STPS data are more than TLD, and MC about 26% and 17%, respectively. More over DICF data can create data with accuracy of 2% in comparison to TLD and MC measurements. Conclusion: In this project for first time developed a 3D GYN‐Cs‐Selectron Treatment Planning Software (TPS) based on Linear TG‐43U1 functions and libraries of MC simulations which modified inter‐source effect, applicator attenuations, and heterogeneity effects.
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SU‐E‐T‐714: Developing a TG‐43U1 Based Dose Calculation Treatment Planning Software for Cs‐137 LDR Brachytherapy
Medical Physics, 2011Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, Mohammad Amin Mosleh-shiraziAbstract:Purpose: Old Treatment Planning systems used for Cs‐137 LDR brachytherapy source use traditional dose calculation method, requiring the exposure rate constant considering each pellet as a point source, not accounting for encapsulation, applicators and spacers' effects. Utilizing such methods would introduce significant errors in dose estimation. The TG‐43 formalism is the main dose calculation formalism in most Treatment Planning Softwares. The purpose of this work is to establish a new algorithm for Treatment Planning based on TG‐43U1 formalism. Methods: STPS Software for brachytherapyTreatment Planning of Selectron Cs‐137 source in Iran, is based on old dose calculation formalism. In this study, a new dose calculation algorithm was esablished based on TG‐43 algorithm for Treatment Planning Software. In this algorithm, the TG‐43 parameters of each active pellet in different places inside the source were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets can be obtained by summing the dose of active sources. The accuracy of this algorithm was checked by comparing the results of this algorithm for special combination of active and inactive pellets with Monte Carlo simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS Software with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is 30%, while the difference between the results of MCNP and the new algorithm is less than 5% at this point. Conclusions: According to the results, dose calculation using “gamma‐ray” based dosimetry formalisms, overestimate the dose especially towards the tip of the applicator. While the new algorithm can perform the dose calculation more accurately.
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su e t 714 developing a tg 43u1 based dose calculation Treatment Planning Software for cs 137 ldr brachytherapy
Medical Physics, 2011Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, M MoslehshiraziAbstract:Purpose: Old Treatment Planning systems used for Cs‐137 LDR brachytherapy source use traditional dose calculation method, requiring the exposure rate constant considering each pellet as a point source, not accounting for encapsulation, applicators and spacers' effects. Utilizing such methods would introduce significant errors in dose estimation. The TG‐43 formalism is the main dose calculation formalism in most Treatment Planning Softwares. The purpose of this work is to establish a new algorithm for Treatment Planning based on TG‐43U1 formalism. Methods: STPS Software for brachytherapyTreatment Planning of Selectron Cs‐137 source in Iran, is based on old dose calculation formalism. In this study, a new dose calculation algorithm was esablished based on TG‐43 algorithm for Treatment Planning Software. In this algorithm, the TG‐43 parameters of each active pellet in different places inside the source were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets can be obtained by summing the dose of active sources. The accuracy of this algorithm was checked by comparing the results of this algorithm for special combination of active and inactive pellets with Monte Carlo simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS Software with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is 30%, while the difference between the results of MCNP and the new algorithm is less than 5% at this point. Conclusions: According to the results, dose calculation using “gamma‐ray” based dosimetry formalisms, overestimate the dose especially towards the tip of the applicator. While the new algorithm can perform the dose calculation more accurately.
Sedigheh Sina - One of the best experts on this subject based on the ideXlab platform.
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Developing a Treatment Planning Software Based on TG-43U1 Formalism for Cs-137 LDR Brachytherapy.
Iranian Red Crescent medical journal, 2013Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, Mohammad Amin Mosleh-shiraziAbstract:Background: The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in Treatment TPSs. Objectives: The purpose of this study is to design and establish a Treatment Planning Software for Cs-137 Solectron brachytherapy source, based on TG-43U1 formalism by applying the effects of the applicator and dummy spacers. Materials and Methods: Two Softwares used for Treatment Planning of Cs-137 sources in Iran (STPS and PLATO), are based on old formalisms. The purpose of this work is to establish and develop a TPS for Selectron source based on TG-43 formalism. In this Planning system, the dosimetry parameters of each pellet in different places inside applicators were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets was obtained by summing the doses. The accuracy of this algorithm was checked by comparing its results for special combination of active and inactive pellets with MC simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS and PLATO Softwares with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is about 30%, while the difference between the results of MCNP and the new algorithm is less than 5%. Conclusions: According to the results, the old dosimetry formalisms, overestimate the dose especially towards the applicator’s tip. While the TG-43U1 based Software perform the calculations more accurately.
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SU‐E‐T‐525: Developing a GYN Cs‐Selectron Brachytherapy Treatment Planning Software Accounting for Inter‐Source, Applicator and Heterogeneity Effects
Medical Physics, 2013Co-Authors: Habib Safigholi, Sedigheh Sina, Dariush Sardari, S Karimi Jashni, M Mosleh‐shirazi, S Karbasi, F Massicano, R Guedes Possoni, H Yoriyaz, Ali S. MeigooniAbstract:Purpose: In this project new Treatment Software based on TG‐43U1 and Monte Carlo (MC) simulations for Treatment of GYN cancers were developed. This Treatment Software accounted for inter‐source effect, applicator attenuation, and tissue heterogeneity for Cs‐137 selectron machine. Methods: MC Linear TG‐43U1 functions for combination of 8 active‐inactive pellets with 2 cm physical length for filling tandem and ovoid were obtained. Total length of tandem and ovoid filled with three and one linear sources, respectively. With this approach inter‐source effect and applicator attenuations have been hidden in TG‐43U1 functions. To account heterogeneity effect in Software design, the library of dose inhomogeneity correction factor (DICF) for various different thickness and position respect to one active Cs pellet for air and aluminum (as a bone) were simulated. A non‐homogen GYN polyethylene phantom were designed, which contain a cylinder of air as a rectum, and two symmetric aluminum spheres as a femur bone heads. GYN reference dosimetry points for TLD detectors were machined in the phantom according ICRU‐38 report. Finally reference points dose rate were compared using new Software, STPS Software, TLD measurements and full MC simulations. Results: New Software data have good agreement with TLD and MC simulations (up to 5%). However STPS data for more reference points are less than TLD and MC simulation (up to 3%) due to not considered applicators and inter‐source attenuation. For tip of tandem and ovoid STPS data are more than TLD, and MC about 26% and 17%, respectively. More over DICF data can create data with accuracy of 2% in comparison to TLD and MC measurements. Conclusion: In this project for first time developed a 3D GYN‐Cs‐Selectron Treatment Planning Software (TPS) based on Linear TG‐43U1 functions and libraries of MC simulations which modified inter‐source effect, applicator attenuations, and heterogeneity effects.
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SU‐E‐T‐714: Developing a TG‐43U1 Based Dose Calculation Treatment Planning Software for Cs‐137 LDR Brachytherapy
Medical Physics, 2011Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, Mohammad Amin Mosleh-shiraziAbstract:Purpose: Old Treatment Planning systems used for Cs‐137 LDR brachytherapy source use traditional dose calculation method, requiring the exposure rate constant considering each pellet as a point source, not accounting for encapsulation, applicators and spacers' effects. Utilizing such methods would introduce significant errors in dose estimation. The TG‐43 formalism is the main dose calculation formalism in most Treatment Planning Softwares. The purpose of this work is to establish a new algorithm for Treatment Planning based on TG‐43U1 formalism. Methods: STPS Software for brachytherapyTreatment Planning of Selectron Cs‐137 source in Iran, is based on old dose calculation formalism. In this study, a new dose calculation algorithm was esablished based on TG‐43 algorithm for Treatment Planning Software. In this algorithm, the TG‐43 parameters of each active pellet in different places inside the source were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets can be obtained by summing the dose of active sources. The accuracy of this algorithm was checked by comparing the results of this algorithm for special combination of active and inactive pellets with Monte Carlo simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS Software with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is 30%, while the difference between the results of MCNP and the new algorithm is less than 5% at this point. Conclusions: According to the results, dose calculation using “gamma‐ray” based dosimetry formalisms, overestimate the dose especially towards the tip of the applicator. While the new algorithm can perform the dose calculation more accurately.
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su e t 714 developing a tg 43u1 based dose calculation Treatment Planning Software for cs 137 ldr brachytherapy
Medical Physics, 2011Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, M MoslehshiraziAbstract:Purpose: Old Treatment Planning systems used for Cs‐137 LDR brachytherapy source use traditional dose calculation method, requiring the exposure rate constant considering each pellet as a point source, not accounting for encapsulation, applicators and spacers' effects. Utilizing such methods would introduce significant errors in dose estimation. The TG‐43 formalism is the main dose calculation formalism in most Treatment Planning Softwares. The purpose of this work is to establish a new algorithm for Treatment Planning based on TG‐43U1 formalism. Methods: STPS Software for brachytherapyTreatment Planning of Selectron Cs‐137 source in Iran, is based on old dose calculation formalism. In this study, a new dose calculation algorithm was esablished based on TG‐43 algorithm for Treatment Planning Software. In this algorithm, the TG‐43 parameters of each active pellet in different places inside the source were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets can be obtained by summing the dose of active sources. The accuracy of this algorithm was checked by comparing the results of this algorithm for special combination of active and inactive pellets with Monte Carlo simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS Software with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is 30%, while the difference between the results of MCNP and the new algorithm is less than 5% at this point. Conclusions: According to the results, dose calculation using “gamma‐ray” based dosimetry formalisms, overestimate the dose especially towards the tip of the applicator. While the new algorithm can perform the dose calculation more accurately.
M Moslehshirazi - One of the best experts on this subject based on the ideXlab platform.
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su e t 525 developing a gyn cs selectron brachytherapy Treatment Planning Software accounting for inter source applicator and heterogeneity effects
Medical Physics, 2013Co-Authors: Habib Safigholi, M Moslehshirazi, Dariush Sardari, S Karbasi, F Massicano, H Yoriyaz, S Sina, Karimi S Jashni, Guedes R Possoni, Ali S. MeigooniAbstract:Purpose: In this project new Treatment Software based on TG‐43U1 and Monte Carlo (MC) simulations for Treatment of GYN cancers were developed. This Treatment Software accounted for inter‐source effect, applicator attenuation, and tissue heterogeneity for Cs‐137 selectron machine. Methods: MC Linear TG‐43U1 functions for combination of 8 active‐inactive pellets with 2 cm physical length for filling tandem and ovoid were obtained. Total length of tandem and ovoid filled with three and one linear sources, respectively. With this approach inter‐source effect and applicator attenuations have been hidden in TG‐43U1 functions. To account heterogeneity effect in Software design, the library of dose inhomogeneity correction factor (DICF) for various different thickness and position respect to one active Cs pellet for air and aluminum (as a bone) were simulated. A non‐homogen GYN polyethylene phantom were designed, which contain a cylinder of air as a rectum, and two symmetric aluminum spheres as a femur bone heads. GYN reference dosimetry points for TLD detectors were machined in the phantom according ICRU‐38 report. Finally reference points dose rate were compared using new Software, STPS Software, TLD measurements and full MC simulations. Results: New Software data have good agreement with TLD and MC simulations (up to 5%). However STPS data for more reference points are less than TLD and MC simulation (up to 3%) due to not considered applicators and inter‐source attenuation. For tip of tandem and ovoid STPS data are more than TLD, and MC about 26% and 17%, respectively. More over DICF data can create data with accuracy of 2% in comparison to TLD and MC measurements. Conclusion: In this project for first time developed a 3D GYN‐Cs‐Selectron Treatment Planning Software (TPS) based on Linear TG‐43U1 functions and libraries of MC simulations which modified inter‐source effect, applicator attenuations, and heterogeneity effects.
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su e t 714 developing a tg 43u1 based dose calculation Treatment Planning Software for cs 137 ldr brachytherapy
Medical Physics, 2011Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, M MoslehshiraziAbstract:Purpose: Old Treatment Planning systems used for Cs‐137 LDR brachytherapy source use traditional dose calculation method, requiring the exposure rate constant considering each pellet as a point source, not accounting for encapsulation, applicators and spacers' effects. Utilizing such methods would introduce significant errors in dose estimation. The TG‐43 formalism is the main dose calculation formalism in most Treatment Planning Softwares. The purpose of this work is to establish a new algorithm for Treatment Planning based on TG‐43U1 formalism. Methods: STPS Software for brachytherapyTreatment Planning of Selectron Cs‐137 source in Iran, is based on old dose calculation formalism. In this study, a new dose calculation algorithm was esablished based on TG‐43 algorithm for Treatment Planning Software. In this algorithm, the TG‐43 parameters of each active pellet in different places inside the source were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets can be obtained by summing the dose of active sources. The accuracy of this algorithm was checked by comparing the results of this algorithm for special combination of active and inactive pellets with Monte Carlo simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS Software with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is 30%, while the difference between the results of MCNP and the new algorithm is less than 5% at this point. Conclusions: According to the results, dose calculation using “gamma‐ray” based dosimetry formalisms, overestimate the dose especially towards the tip of the applicator. While the new algorithm can perform the dose calculation more accurately.
Habib Safigholi - One of the best experts on this subject based on the ideXlab platform.
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SU‐E‐T‐525: Developing a GYN Cs‐Selectron Brachytherapy Treatment Planning Software Accounting for Inter‐Source, Applicator and Heterogeneity Effects
Medical Physics, 2013Co-Authors: Habib Safigholi, Sedigheh Sina, Dariush Sardari, S Karimi Jashni, M Mosleh‐shirazi, S Karbasi, F Massicano, R Guedes Possoni, H Yoriyaz, Ali S. MeigooniAbstract:Purpose: In this project new Treatment Software based on TG‐43U1 and Monte Carlo (MC) simulations for Treatment of GYN cancers were developed. This Treatment Software accounted for inter‐source effect, applicator attenuation, and tissue heterogeneity for Cs‐137 selectron machine. Methods: MC Linear TG‐43U1 functions for combination of 8 active‐inactive pellets with 2 cm physical length for filling tandem and ovoid were obtained. Total length of tandem and ovoid filled with three and one linear sources, respectively. With this approach inter‐source effect and applicator attenuations have been hidden in TG‐43U1 functions. To account heterogeneity effect in Software design, the library of dose inhomogeneity correction factor (DICF) for various different thickness and position respect to one active Cs pellet for air and aluminum (as a bone) were simulated. A non‐homogen GYN polyethylene phantom were designed, which contain a cylinder of air as a rectum, and two symmetric aluminum spheres as a femur bone heads. GYN reference dosimetry points for TLD detectors were machined in the phantom according ICRU‐38 report. Finally reference points dose rate were compared using new Software, STPS Software, TLD measurements and full MC simulations. Results: New Software data have good agreement with TLD and MC simulations (up to 5%). However STPS data for more reference points are less than TLD and MC simulation (up to 3%) due to not considered applicators and inter‐source attenuation. For tip of tandem and ovoid STPS data are more than TLD, and MC about 26% and 17%, respectively. More over DICF data can create data with accuracy of 2% in comparison to TLD and MC measurements. Conclusion: In this project for first time developed a 3D GYN‐Cs‐Selectron Treatment Planning Software (TPS) based on Linear TG‐43U1 functions and libraries of MC simulations which modified inter‐source effect, applicator attenuations, and heterogeneity effects.
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su e t 525 developing a gyn cs selectron brachytherapy Treatment Planning Software accounting for inter source applicator and heterogeneity effects
Medical Physics, 2013Co-Authors: Habib Safigholi, M Moslehshirazi, Dariush Sardari, S Karbasi, F Massicano, H Yoriyaz, S Sina, Karimi S Jashni, Guedes R Possoni, Ali S. MeigooniAbstract:Purpose: In this project new Treatment Software based on TG‐43U1 and Monte Carlo (MC) simulations for Treatment of GYN cancers were developed. This Treatment Software accounted for inter‐source effect, applicator attenuation, and tissue heterogeneity for Cs‐137 selectron machine. Methods: MC Linear TG‐43U1 functions for combination of 8 active‐inactive pellets with 2 cm physical length for filling tandem and ovoid were obtained. Total length of tandem and ovoid filled with three and one linear sources, respectively. With this approach inter‐source effect and applicator attenuations have been hidden in TG‐43U1 functions. To account heterogeneity effect in Software design, the library of dose inhomogeneity correction factor (DICF) for various different thickness and position respect to one active Cs pellet for air and aluminum (as a bone) were simulated. A non‐homogen GYN polyethylene phantom were designed, which contain a cylinder of air as a rectum, and two symmetric aluminum spheres as a femur bone heads. GYN reference dosimetry points for TLD detectors were machined in the phantom according ICRU‐38 report. Finally reference points dose rate were compared using new Software, STPS Software, TLD measurements and full MC simulations. Results: New Software data have good agreement with TLD and MC simulations (up to 5%). However STPS data for more reference points are less than TLD and MC simulation (up to 3%) due to not considered applicators and inter‐source attenuation. For tip of tandem and ovoid STPS data are more than TLD, and MC about 26% and 17%, respectively. More over DICF data can create data with accuracy of 2% in comparison to TLD and MC measurements. Conclusion: In this project for first time developed a 3D GYN‐Cs‐Selectron Treatment Planning Software (TPS) based on Linear TG‐43U1 functions and libraries of MC simulations which modified inter‐source effect, applicator attenuations, and heterogeneity effects.
Mohammad Amin Mosleh-shirazi - One of the best experts on this subject based on the ideXlab platform.
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Developing a Treatment Planning Software Based on TG-43U1 Formalism for Cs-137 LDR Brachytherapy.
Iranian Red Crescent medical journal, 2013Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, Mohammad Amin Mosleh-shiraziAbstract:Background: The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in Treatment TPSs. Objectives: The purpose of this study is to design and establish a Treatment Planning Software for Cs-137 Solectron brachytherapy source, based on TG-43U1 formalism by applying the effects of the applicator and dummy spacers. Materials and Methods: Two Softwares used for Treatment Planning of Cs-137 sources in Iran (STPS and PLATO), are based on old formalisms. The purpose of this work is to establish and develop a TPS for Selectron source based on TG-43 formalism. In this Planning system, the dosimetry parameters of each pellet in different places inside applicators were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets was obtained by summing the doses. The accuracy of this algorithm was checked by comparing its results for special combination of active and inactive pellets with MC simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS and PLATO Softwares with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is about 30%, while the difference between the results of MCNP and the new algorithm is less than 5%. Conclusions: According to the results, the old dosimetry formalisms, overestimate the dose especially towards the applicator’s tip. While the TG-43U1 based Software perform the calculations more accurately.
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SU‐E‐T‐714: Developing a TG‐43U1 Based Dose Calculation Treatment Planning Software for Cs‐137 LDR Brachytherapy
Medical Physics, 2011Co-Authors: Sedigheh Sina, Reza Faghihi, Ali S. Meigooni, Z. Siavashpour, Mohammad Amin Mosleh-shiraziAbstract:Purpose: Old Treatment Planning systems used for Cs‐137 LDR brachytherapy source use traditional dose calculation method, requiring the exposure rate constant considering each pellet as a point source, not accounting for encapsulation, applicators and spacers' effects. Utilizing such methods would introduce significant errors in dose estimation. The TG‐43 formalism is the main dose calculation formalism in most Treatment Planning Softwares. The purpose of this work is to establish a new algorithm for Treatment Planning based on TG‐43U1 formalism. Methods: STPS Software for brachytherapyTreatment Planning of Selectron Cs‐137 source in Iran, is based on old dose calculation formalism. In this study, a new dose calculation algorithm was esablished based on TG‐43 algorithm for Treatment Planning Software. In this algorithm, the TG‐43 parameters of each active pellet in different places inside the source were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets can be obtained by summing the dose of active sources. The accuracy of this algorithm was checked by comparing the results of this algorithm for special combination of active and inactive pellets with Monte Carlo simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS Software with those obtained by the new algorithm. Results: For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is 30%, while the difference between the results of MCNP and the new algorithm is less than 5% at this point. Conclusions: According to the results, dose calculation using “gamma‐ray” based dosimetry formalisms, overestimate the dose especially towards the tip of the applicator. While the new algorithm can perform the dose calculation more accurately.
