Journal Articles
2018
DeCunha, Joseph M.; Enger, Shirin A.
A new delivery system to resolve dosimetric issues in intravascular brachytherapy Journal Article
In: Brachytherapy, vol. 17, no. 3, pp. 634–643, 2018, ISSN: 1873-1449.
Abstract | Links | BibTeX | Tags: Brachytherapy, Catheterization, Catheters, Computer Simulation, Coronary Vessels, Humans, Intravascular, Monte Carlo Method, Physics, Radiation Dosage, Radiometry, Restenosis, Stents, Strontium Radioisotopes
@article{decunha_new_2018,
title = {A new delivery system to resolve dosimetric issues in intravascular brachytherapy},
author = {Joseph M. DeCunha and Shirin A. Enger},
doi = {10.1016/j.brachy.2018.01.012},
issn = {1873-1449},
year = {2018},
date = {2018-06-01},
journal = {Brachytherapy},
volume = {17},
number = {3},
pages = {634--643},
abstract = {PURPOSE: Renewed interest is being expressed in intravascular brachytherapy (IVBT). A number of unresolved issues exist in the discipline. Providing a homogeneous and adequate dose to the target remains difficult in IVBT. The guidewire that delivers the device to the target, arterial plaques, and stent struts are all known to reduce the dose delivered to target. The viability and efficacy of a proposed IVBT delivery system designed to resolve the issue of guidewire attenuation is evaluated and compared to that of a popular and commercially available IVBT device.
METHODS AND MATERIALS: Monte Carlo simulations are conducted to determine distributions of absorbed dose around an existing and proposed IVBT delivery system.
RESULTS: For the Novoste Beta-Cath 3.5F (TeamBest®), dose in water varies by 10% as a function of angle in the plane perpendicular to the delivery catheter due to off-centering of seeds in the catheter. Dose is reduced by 52% behind a stainless steel guidewire and 64% behind a guidewire, arterial plaque, and stent strut for the Novoste Beta-Cath 3.5F. Dose is not perturbed by the presence of a guidewire for the proposed device and is reduced by 46% by an arterial plaque and stent strut.
CONCLUSIONS: Dose attenuation by guidewire is likely the single greatest source of dose attenuation in IVBT in terms of absolute dose reduction and is greater than previously reported for the Novoste Beta-Cath 3.5F. The Novoste Beta-Cath 3.5F delivers an inhomogeneous dose to target. A delivery system is proposed, which resolves the issue of guidewire attenuation in IVBT and should reduce treatment times.},
keywords = {Brachytherapy, Catheterization, Catheters, Computer Simulation, Coronary Vessels, Humans, Intravascular, Monte Carlo Method, Physics, Radiation Dosage, Radiometry, Restenosis, Stents, Strontium Radioisotopes},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: Renewed interest is being expressed in intravascular brachytherapy (IVBT). A number of unresolved issues exist in the discipline. Providing a homogeneous and adequate dose to the target remains difficult in IVBT. The guidewire that delivers the device to the target, arterial plaques, and stent struts are all known to reduce the dose delivered to target. The viability and efficacy of a proposed IVBT delivery system designed to resolve the issue of guidewire attenuation is evaluated and compared to that of a popular and commercially available IVBT device.
METHODS AND MATERIALS: Monte Carlo simulations are conducted to determine distributions of absorbed dose around an existing and proposed IVBT delivery system.
RESULTS: For the Novoste Beta-Cath 3.5F (TeamBest®), dose in water varies by 10% as a function of angle in the plane perpendicular to the delivery catheter due to off-centering of seeds in the catheter. Dose is reduced by 52% behind a stainless steel guidewire and 64% behind a guidewire, arterial plaque, and stent strut for the Novoste Beta-Cath 3.5F. Dose is not perturbed by the presence of a guidewire for the proposed device and is reduced by 46% by an arterial plaque and stent strut.
CONCLUSIONS: Dose attenuation by guidewire is likely the single greatest source of dose attenuation in IVBT in terms of absolute dose reduction and is greater than previously reported for the Novoste Beta-Cath 3.5F. The Novoste Beta-Cath 3.5F delivers an inhomogeneous dose to target. A delivery system is proposed, which resolves the issue of guidewire attenuation in IVBT and should reduce treatment times.2006
Enger, Shirin A.; Rezaei, Arash; af Rosenschöld, Per Munck; Lundqvist, Hans
Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy Journal Article
In: Medical Physics, vol. 33, no. 1, pp. 46–51, 2006, ISSN: 0094-2405.
Abstract | Links | BibTeX | Tags: Biological, Blood Vessel Prosthesis, Brachytherapy, Computer Simulation, Computer-Assisted, Gadolinium, Graft Occlusion, Humans, Models, Monte Carlo Method, Neutron Capture Therapy, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Relative Biological Effectiveness, Statistical, Stents, Vascular
@article{enger_gadolinium_2006,
title = {Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy},
author = {Shirin A. Enger and Arash Rezaei and Per Munck af Rosenschöld and Hans Lundqvist},
doi = {10.1118/1.2146050},
issn = {0094-2405},
year = {2006},
date = {2006-01-01},
journal = {Medical Physics},
volume = {33},
number = {1},
pages = {46--51},
abstract = {Restenosis is a major problem after balloon angioplasty and stent implantation. The aim of this study is to introduce gadolinium neutron capture brachytherapy (GdNCB) as a suitable modality for treatment of stenosis. The utility of GdNCB in intravascular brachytherapy (IVBT) of stent stenosis is investigated by using the GEANT4 and MCNP4B Monte Carlo radiation transport codes. To study capture rate, Kerma, absorbed dose and absorbed dose rate around a Gd-containing stent activated with neutrons, a 30 mm long, 5 mm diameter gadolinium foil is chosen. The input data is a neutron spectrum used for clinical neutron capture therapy in Studsvik, Sweden. Thermal neutron capture in gadolinium yields a spectrum of high-energy gamma photons, which due to the build-up effect gives an almost flat dose delivery pattern to the first 4 mm around the stent. The absorbed dose rate is 1.33 Gy/min, 0.25 mm from the stent surface while the dose to normal tissue is in order of 0.22 Gy/min, i.e., a factor of 6 lower. To spare normal tissue further fractionation of the dose is also possible. The capture rate is relatively high at both ends of the foil. The dose distribution from gamma and charge particle radiation at the edges and inside the stent contributes to a nonuniform dose distribution. This will lead to higher doses to the surrounding tissue and may prevent stent edge and in-stent restenosis. The position of the stent can be verified and corrected by the treatment plan prior to activation. Activation of the stent by an external neutron field can be performed days after catherization when the target cells start to proliferate and can be expected to be more radiation sensitive. Another advantage of the nonradioactive gadolinium stent is the possibility to avoid radiation hazard to personnel.},
keywords = {Biological, Blood Vessel Prosthesis, Brachytherapy, Computer Simulation, Computer-Assisted, Gadolinium, Graft Occlusion, Humans, Models, Monte Carlo Method, Neutron Capture Therapy, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Relative Biological Effectiveness, Statistical, Stents, Vascular},
pubstate = {published},
tppubtype = {article}
}
Restenosis is a major problem after balloon angioplasty and stent implantation. The aim of this study is to introduce gadolinium neutron capture brachytherapy (GdNCB) as a suitable modality for treatment of stenosis. The utility of GdNCB in intravascular brachytherapy (IVBT) of stent stenosis is investigated by using the GEANT4 and MCNP4B Monte Carlo radiation transport codes. To study capture rate, Kerma, absorbed dose and absorbed dose rate around a Gd-containing stent activated with neutrons, a 30 mm long, 5 mm diameter gadolinium foil is chosen. The input data is a neutron spectrum used for clinical neutron capture therapy in Studsvik, Sweden. Thermal neutron capture in gadolinium yields a spectrum of high-energy gamma photons, which due to the build-up effect gives an almost flat dose delivery pattern to the first 4 mm around the stent. The absorbed dose rate is 1.33 Gy/min, 0.25 mm from the stent surface while the dose to normal tissue is in order of 0.22 Gy/min, i.e., a factor of 6 lower. To spare normal tissue further fractionation of the dose is also possible. The capture rate is relatively high at both ends of the foil. The dose distribution from gamma and charge particle radiation at the edges and inside the stent contributes to a nonuniform dose distribution. This will lead to higher doses to the surrounding tissue and may prevent stent edge and in-stent restenosis. The position of the stent can be verified and corrected by the treatment plan prior to activation. Activation of the stent by an external neutron field can be performed days after catherization when the target cells start to proliferate and can be expected to be more radiation sensitive. Another advantage of the nonradioactive gadolinium stent is the possibility to avoid radiation hazard to personnel.
Journal Articles
2018
DeCunha, Joseph M.; Enger, Shirin A.
A new delivery system to resolve dosimetric issues in intravascular brachytherapy Journal Article
In: Brachytherapy, vol. 17, no. 3, pp. 634–643, 2018, ISSN: 1873-1449.
Abstract | Links | BibTeX | Tags: Brachytherapy, Catheterization, Catheters, Computer Simulation, Coronary Vessels, Humans, Intravascular, Monte Carlo Method, Physics, Radiation Dosage, Radiometry, Restenosis, Stents, Strontium Radioisotopes
@article{decunha_new_2018,
title = {A new delivery system to resolve dosimetric issues in intravascular brachytherapy},
author = {Joseph M. DeCunha and Shirin A. Enger},
doi = {10.1016/j.brachy.2018.01.012},
issn = {1873-1449},
year = {2018},
date = {2018-06-01},
journal = {Brachytherapy},
volume = {17},
number = {3},
pages = {634--643},
abstract = {PURPOSE: Renewed interest is being expressed in intravascular brachytherapy (IVBT). A number of unresolved issues exist in the discipline. Providing a homogeneous and adequate dose to the target remains difficult in IVBT. The guidewire that delivers the device to the target, arterial plaques, and stent struts are all known to reduce the dose delivered to target. The viability and efficacy of a proposed IVBT delivery system designed to resolve the issue of guidewire attenuation is evaluated and compared to that of a popular and commercially available IVBT device.
METHODS AND MATERIALS: Monte Carlo simulations are conducted to determine distributions of absorbed dose around an existing and proposed IVBT delivery system.
RESULTS: For the Novoste Beta-Cath 3.5F (TeamBest®), dose in water varies by 10% as a function of angle in the plane perpendicular to the delivery catheter due to off-centering of seeds in the catheter. Dose is reduced by 52% behind a stainless steel guidewire and 64% behind a guidewire, arterial plaque, and stent strut for the Novoste Beta-Cath 3.5F. Dose is not perturbed by the presence of a guidewire for the proposed device and is reduced by 46% by an arterial plaque and stent strut.
CONCLUSIONS: Dose attenuation by guidewire is likely the single greatest source of dose attenuation in IVBT in terms of absolute dose reduction and is greater than previously reported for the Novoste Beta-Cath 3.5F. The Novoste Beta-Cath 3.5F delivers an inhomogeneous dose to target. A delivery system is proposed, which resolves the issue of guidewire attenuation in IVBT and should reduce treatment times.},
keywords = {Brachytherapy, Catheterization, Catheters, Computer Simulation, Coronary Vessels, Humans, Intravascular, Monte Carlo Method, Physics, Radiation Dosage, Radiometry, Restenosis, Stents, Strontium Radioisotopes},
pubstate = {published},
tppubtype = {article}
}
PURPOSE: Renewed interest is being expressed in intravascular brachytherapy (IVBT). A number of unresolved issues exist in the discipline. Providing a homogeneous and adequate dose to the target remains difficult in IVBT. The guidewire that delivers the device to the target, arterial plaques, and stent struts are all known to reduce the dose delivered to target. The viability and efficacy of a proposed IVBT delivery system designed to resolve the issue of guidewire attenuation is evaluated and compared to that of a popular and commercially available IVBT device.
METHODS AND MATERIALS: Monte Carlo simulations are conducted to determine distributions of absorbed dose around an existing and proposed IVBT delivery system.
RESULTS: For the Novoste Beta-Cath 3.5F (TeamBest®), dose in water varies by 10% as a function of angle in the plane perpendicular to the delivery catheter due to off-centering of seeds in the catheter. Dose is reduced by 52% behind a stainless steel guidewire and 64% behind a guidewire, arterial plaque, and stent strut for the Novoste Beta-Cath 3.5F. Dose is not perturbed by the presence of a guidewire for the proposed device and is reduced by 46% by an arterial plaque and stent strut.
CONCLUSIONS: Dose attenuation by guidewire is likely the single greatest source of dose attenuation in IVBT in terms of absolute dose reduction and is greater than previously reported for the Novoste Beta-Cath 3.5F. The Novoste Beta-Cath 3.5F delivers an inhomogeneous dose to target. A delivery system is proposed, which resolves the issue of guidewire attenuation in IVBT and should reduce treatment times.
METHODS AND MATERIALS: Monte Carlo simulations are conducted to determine distributions of absorbed dose around an existing and proposed IVBT delivery system.
RESULTS: For the Novoste Beta-Cath 3.5F (TeamBest®), dose in water varies by 10% as a function of angle in the plane perpendicular to the delivery catheter due to off-centering of seeds in the catheter. Dose is reduced by 52% behind a stainless steel guidewire and 64% behind a guidewire, arterial plaque, and stent strut for the Novoste Beta-Cath 3.5F. Dose is not perturbed by the presence of a guidewire for the proposed device and is reduced by 46% by an arterial plaque and stent strut.
CONCLUSIONS: Dose attenuation by guidewire is likely the single greatest source of dose attenuation in IVBT in terms of absolute dose reduction and is greater than previously reported for the Novoste Beta-Cath 3.5F. The Novoste Beta-Cath 3.5F delivers an inhomogeneous dose to target. A delivery system is proposed, which resolves the issue of guidewire attenuation in IVBT and should reduce treatment times.
2006
Enger, Shirin A.; Rezaei, Arash; af Rosenschöld, Per Munck; Lundqvist, Hans
Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy Journal Article
In: Medical Physics, vol. 33, no. 1, pp. 46–51, 2006, ISSN: 0094-2405.
Abstract | Links | BibTeX | Tags: Biological, Blood Vessel Prosthesis, Brachytherapy, Computer Simulation, Computer-Assisted, Gadolinium, Graft Occlusion, Humans, Models, Monte Carlo Method, Neutron Capture Therapy, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Relative Biological Effectiveness, Statistical, Stents, Vascular
@article{enger_gadolinium_2006,
title = {Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy},
author = {Shirin A. Enger and Arash Rezaei and Per Munck af Rosenschöld and Hans Lundqvist},
doi = {10.1118/1.2146050},
issn = {0094-2405},
year = {2006},
date = {2006-01-01},
journal = {Medical Physics},
volume = {33},
number = {1},
pages = {46--51},
abstract = {Restenosis is a major problem after balloon angioplasty and stent implantation. The aim of this study is to introduce gadolinium neutron capture brachytherapy (GdNCB) as a suitable modality for treatment of stenosis. The utility of GdNCB in intravascular brachytherapy (IVBT) of stent stenosis is investigated by using the GEANT4 and MCNP4B Monte Carlo radiation transport codes. To study capture rate, Kerma, absorbed dose and absorbed dose rate around a Gd-containing stent activated with neutrons, a 30 mm long, 5 mm diameter gadolinium foil is chosen. The input data is a neutron spectrum used for clinical neutron capture therapy in Studsvik, Sweden. Thermal neutron capture in gadolinium yields a spectrum of high-energy gamma photons, which due to the build-up effect gives an almost flat dose delivery pattern to the first 4 mm around the stent. The absorbed dose rate is 1.33 Gy/min, 0.25 mm from the stent surface while the dose to normal tissue is in order of 0.22 Gy/min, i.e., a factor of 6 lower. To spare normal tissue further fractionation of the dose is also possible. The capture rate is relatively high at both ends of the foil. The dose distribution from gamma and charge particle radiation at the edges and inside the stent contributes to a nonuniform dose distribution. This will lead to higher doses to the surrounding tissue and may prevent stent edge and in-stent restenosis. The position of the stent can be verified and corrected by the treatment plan prior to activation. Activation of the stent by an external neutron field can be performed days after catherization when the target cells start to proliferate and can be expected to be more radiation sensitive. Another advantage of the nonradioactive gadolinium stent is the possibility to avoid radiation hazard to personnel.},
keywords = {Biological, Blood Vessel Prosthesis, Brachytherapy, Computer Simulation, Computer-Assisted, Gadolinium, Graft Occlusion, Humans, Models, Monte Carlo Method, Neutron Capture Therapy, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Relative Biological Effectiveness, Statistical, Stents, Vascular},
pubstate = {published},
tppubtype = {article}
}
Restenosis is a major problem after balloon angioplasty and stent implantation. The aim of this study is to introduce gadolinium neutron capture brachytherapy (GdNCB) as a suitable modality for treatment of stenosis. The utility of GdNCB in intravascular brachytherapy (IVBT) of stent stenosis is investigated by using the GEANT4 and MCNP4B Monte Carlo radiation transport codes. To study capture rate, Kerma, absorbed dose and absorbed dose rate around a Gd-containing stent activated with neutrons, a 30 mm long, 5 mm diameter gadolinium foil is chosen. The input data is a neutron spectrum used for clinical neutron capture therapy in Studsvik, Sweden. Thermal neutron capture in gadolinium yields a spectrum of high-energy gamma photons, which due to the build-up effect gives an almost flat dose delivery pattern to the first 4 mm around the stent. The absorbed dose rate is 1.33 Gy/min, 0.25 mm from the stent surface while the dose to normal tissue is in order of 0.22 Gy/min, i.e., a factor of 6 lower. To spare normal tissue further fractionation of the dose is also possible. The capture rate is relatively high at both ends of the foil. The dose distribution from gamma and charge particle radiation at the edges and inside the stent contributes to a nonuniform dose distribution. This will lead to higher doses to the surrounding tissue and may prevent stent edge and in-stent restenosis. The position of the stent can be verified and corrected by the treatment plan prior to activation. Activation of the stent by an external neutron field can be performed days after catherization when the target cells start to proliferate and can be expected to be more radiation sensitive. Another advantage of the nonradioactive gadolinium stent is the possibility to avoid radiation hazard to personnel.