Mission
The detector development group works to build novel radiation detectors to solve clinical problems. We use a mix of computer simulations lab-based tests and clinical simulations to develop precise and easy use detectors that can be easily implemented in clinical practice.
Members
Projects
Dosimetry Detectors
Dosimetry is the practice of quantitatively determining the energy deposited in a medium by ionizing radiation. The major challenge in radiotherapy is to deliver and quantify an accurate dose of radiation to the tumor. Several dosimetry techniques are available to measure the radiation dose, but they have limitations. In particular, the non-tissue equivalence of the detector housing/material and the sensitive volume leads to perturbations of the radiation fluence and necessitates correction factors. Another constraint placed on conventional dosimetry techniques is the limited resolution. Currently, there are many ongoing research projects regarding detector development for quality assurance and in-vivo dosimetry in radiotherapy.
Imaging Detector
Dynamic positron emission tomography is a nuclear medicine imaging technique providing functional images for organs of interest with applications in oncology, cardiology, and drug discovery. This technique requires the acquisition of the time-course arterial plasma activity concentration, called the arterial input function, which is normally acquired invasively via arterial blood sampling. Currently, we are developing a radiation detector to measure the arterial input function non-invasively.
Detector Group Publications
2023
Carroll, Liam; Enger, Shirin A.
M-TAG: A modular teaching-aid for Geant4 Journal Article
In: Heliyon, 2023.
@article{nokey,
title = {M-TAG: A modular teaching-aid for Geant4},
author = {Liam Carroll and Shirin A. Enger},
year = {2023},
date = {2023-09-19},
urldate = {2023-09-19},
journal = {Heliyon},
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pubstate = {published},
tppubtype = {article}
}
Mégrourèche, Julien; Bekerat, Hamed; Bian, Jingyi; Bui, Alaina; Sankey, Jack; Childress, Lilian; Enger, Shirin A.
Development of a hydrated electron dosimeter for radiotherapy applications: A proof of concept Journal Article
In: Medical Physics, 2023.
@article{nokey,
title = {Development of a hydrated electron dosimeter for radiotherapy applications: A proof of concept},
author = {Julien Mégrourèche and Hamed Bekerat and Jingyi Bian and Alaina Bui and Jack Sankey and Lilian Childress and Shirin A. Enger},
doi = {10.1002/mp.16555},
year = {2023},
date = {2023-06-19},
urldate = {2023-06-19},
journal = {Medical Physics},
abstract = {Background: Hydrated electrons, which are short-lived products of radiolysis in water, increase the optical absorption of water, providing a pathway toward near-tissue-equivalent clinical radiation dosimeters. This has been demonstrated in high-dose-per-pulse radiochemistry research, but, owing to the weak absorption signal, its application in existing low-dose-per-pulse radiotherapy provided by clinical linear accelerators (linacs) has yet to be investigated.
Purpose: The aims of this study were to measure the optical absorption associated with hydrated electrons produced by clinical linacs and to assess the suitability of the technique for radiotherapy (⩽ 1 cGy per pulse) applications.
Methods: 40 mW of 660-nm laser light was sent five passes through deionized water contained in a 10
×
4
×
2 cm3 glass-walled cavity by using four broadband dielectric mirrors, two on each side of the cavity. The light was collected with a biased silicon photodetector. The water cavity was then irradiated by a Varian TrueBeam linac with both photon (10 MV FFF, 6 MV FFF, 6 MV) and electron beams (6 MeV) while monitoring the transmitted laser power for absorption transients. Radiochromic EBT3 film measurements were also performed for comparison.
Results: Examination of the absorbance profiles showed clear absorption changes in the water when radiation pulses were delivered. Both the amplitude and the decay time of the signal appeared consistent with the absorbed dose and the characteristics of the hydrated electrons. By using literature value for the hydrated electron radiation chemical yield (3.0±0.3), we inferred doses of 2.1±0.2 mGy (10 MV FFF), 1.3±0.1 mGy (6 MV FFF), 0.45±0.06 mGy (6 MV) for photons, and 0.47±0.05 mGy (6 MeV) for electrons, which differed from EBT3 film measurements by 0.6%, 0.8%, 10%, and 15.7%, respectively. The half-life of the hydrated electrons in the solution was ∼ 24
μs.
Conclusions: By measuring 660-nm laser light transmitted through a cm-scale, multi-pass water cavity, we observed absorption transients consistent with hydrated electrons generated by clinical linac radiation. The agreement between our inferred dose and EBT3 film measurements suggests this proof-of-concept system represents a viable pathway toward tissue-equivalent dosimeters for clinical radiotherapy applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Purpose: The aims of this study were to measure the optical absorption associated with hydrated electrons produced by clinical linacs and to assess the suitability of the technique for radiotherapy (⩽ 1 cGy per pulse) applications.
Methods: 40 mW of 660-nm laser light was sent five passes through deionized water contained in a 10
×
4
×
2 cm3 glass-walled cavity by using four broadband dielectric mirrors, two on each side of the cavity. The light was collected with a biased silicon photodetector. The water cavity was then irradiated by a Varian TrueBeam linac with both photon (10 MV FFF, 6 MV FFF, 6 MV) and electron beams (6 MeV) while monitoring the transmitted laser power for absorption transients. Radiochromic EBT3 film measurements were also performed for comparison.
Results: Examination of the absorbance profiles showed clear absorption changes in the water when radiation pulses were delivered. Both the amplitude and the decay time of the signal appeared consistent with the absorbed dose and the characteristics of the hydrated electrons. By using literature value for the hydrated electron radiation chemical yield (3.0±0.3), we inferred doses of 2.1±0.2 mGy (10 MV FFF), 1.3±0.1 mGy (6 MV FFF), 0.45±0.06 mGy (6 MV) for photons, and 0.47±0.05 mGy (6 MeV) for electrons, which differed from EBT3 film measurements by 0.6%, 0.8%, 10%, and 15.7%, respectively. The half-life of the hydrated electrons in the solution was ∼ 24
μs.
Conclusions: By measuring 660-nm laser light transmitted through a cm-scale, multi-pass water cavity, we observed absorption transients consistent with hydrated electrons generated by clinical linac radiation. The agreement between our inferred dose and EBT3 film measurements suggests this proof-of-concept system represents a viable pathway toward tissue-equivalent dosimeters for clinical radiotherapy applications.
Bian, Jingyi; Duran, Juan; Shin, Wook-Geun; Ramos-Méndez, Jose; Sankey, Jack C; Childress, Lilian; Seuntjens, Jan; Enger, Shirin A
GEANT4-DNA simulation of temperature-dependent and pH-dependent yields of chemical radiolytic species Journal Article
In: Physics in Medicine & Biology, 2023.
@article{nokey_33,
title = {GEANT4-DNA simulation of temperature-dependent and pH-dependent yields of chemical radiolytic species},
author = {Jingyi Bian and Juan Duran and Wook-Geun Shin and Jose Ramos-Méndez and Jack C Sankey and Lilian Childress and Jan Seuntjens and Shirin A Enger
},
doi = {10.1088/1361-6560/acd90d},
year = {2023},
date = {2023-06-15},
journal = {Physics in Medicine & Biology},
abstract = {Objective.GEANT4-DNA can simulate radiation chemical yield (G-value) for radiolytic species such as the hydrated electron (eaq-) with the independent reaction times (IRT) method, however, only at room temperature and neutral pH. This work aims to modify the GEANT4-DNA source code to enable the calculation ofG-values for radiolytic species at different temperatures and pH values.Approach.In the GEANT4-DNA source code, values of chemical parameters such as reaction rate constant, diffusion coefficient, Onsager radius, and water density were replaced by corresponding temperature-dependent polynomials. The initial concentration of hydrogen ion (H+)/hydronium ion (H3O+) was scaled for a desired pH using the relationship pH = -log10[H+]. To validate our modifications, two sets of simulations were performed. (A) A water cube with 1.0 km sides and a pH of 7 was irradiated with an isotropic electron source of 1 MeV. The end time was 1μs. The temperatures varied from 25 °C to 150 °C. (B) The same setup as (A) was used, however, the temperature was set to 25 °C while the pH varied from 5 to 9. The results were compared with published experimental and simulated work.Main results.The IRT method in GEANT4-DNA was successfully modified to simulateG-values for radiolytic species at different temperatures and pH values. Our temperature-dependent results agreed with experimental data within 0.64%-9.79%, and with simulated data within 3.52%-12.47%. The pH-dependent results agreed well with experimental data within 0.52% to 3.19% except at a pH of 5 (15.99%) and with simulated data within 4.40%-5.53%. The uncertainties were below ±0.20%. Overall our results agreed better with experimental than simulation data.Significance.Modifications in the GEANT4-DNA code enabled the calculation ofG-values for radiolytic species at different temperatures and pH values.},
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pubstate = {published},
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Bui, Alaina; Bekerat, Hamed; Childress, Lilian; Sankey, Jack; Seuntjens, Jan; Enger, Shirin A.
Effects of incoming particle energy and cluster size on the G-value of hydrated electrons Journal Article
In: Physics in Medicine & Biology, 2023.
@article{nokey_27,
title = {Effects of incoming particle energy and cluster size on the G-value of hydrated electrons},
author = {Alaina Bui and Hamed Bekerat and Lilian Childress and Jack Sankey and Jan Seuntjens and Shirin A. Enger},
url = {https://doi.org/10.1016/j.ejmp.2023.102540},
doi = {10.1016/j.ejmp.2023.102540},
year = {2023},
date = {2023-02-16},
urldate = {2023-02-16},
journal = {Physics in Medicine & Biology},
abstract = {In hydrated electron (e-aq) dosimetry, absorbed radiation dose to water is measured by monitoring the concentration of radiation-induced e-aq. However, to obtain accurate dose, the radiation chemical yield of e-aq, G(e-aq), is needed for the radiation quality/setup under investigation. The aim of this study was to investigate the time-evolution of the G-values for the main generated reactive species during water radiolysis using GEANT4-DNA. The effects of cluster size and linear energy transfer (LET) on G(e-aq) were examined. Validity of GEANT4-DNA for calculation of G(e-aq) for clinically relevant energies was studied. Three scenarios were investigated with different phantom sizes and incoming electron energies (1 keV to 1 MeV). The time evolution of G(e-aq) was in good agreement with published data and did not change with decreasing phantom size. The time-evolution of the G-values increases with increasing LET for all radiolytic species. The particle tracks formed with high-energy electrons are separated and the resulting reactive species develop independently in time. With decreasing energy, the mean separation distance between reactive species decreases. The particle tracks might not initially overlap but will overlap shortly thereafter due to diffusion of reactive species, increasing the probability of e-aq recombination with other species. This also explains the decrease of G(e-aq) with cluster size and LET. Finally, if all factors are kept constant, as the incoming electron energy increases to clinically relevant energies, G(e-aq) remains similar to its value at 1 MeV, hence GEANT4-DNA can be used for clinically relevant energies.},
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2022
Carroll, Liam; Enger, Shirin A.
Compact radiation detector could expedite the use of dynamic PET Online
2022, visited: 16.12.2022.
@online{nokey_31,
title = {Compact radiation detector could expedite the use of dynamic PET},
author = {Liam Carroll and Shirin A. Enger},
url = {https://physicsworld.com/a/compact-radiation-detector-could-expedite-the-use-of-dynamic-pet/},
doi = {10.1002/mp.16055},
year = {2022},
date = {2022-12-16},
urldate = {2022-12-16},
journal = {Medical Physics},
keywords = {},
pubstate = {published},
tppubtype = {online}
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Carroll, Liam; Enger, Shirin A.
Simulation of a novel, non-invasive radiation detector to measure the arterial input function for dynamic PET Journal Article
In: Medical Physics , 2022.
@article{nokey,
title = {Simulation of a novel, non-invasive radiation detector to measure the arterial input function for dynamic PET},
author = {Liam Carroll and Shirin A. Enger},
url = {https://doi-org.proxy3.library.mcgill.ca/10.1002/mp.16055
},
doi = {10.1002/mp.16055},
year = {2022},
date = {2022-10-17},
urldate = {2022-10-17},
journal = {Medical Physics },
abstract = {Background:
Dynamic positron emission tomography (dPET) is a nuclear medicine imaging technique providing functional images for organs of interest with applications in oncology, cardiology, and drug discovery. This technique requires the acquisition of the time-course arterial plasma activity concentration, called the arterial input function (AIF), which is conventionally acquired via arterial blood sampling.
Purpose:
The aim of this study was to A) optimize the geometry for a novel and cost efficient non-invasive detector called NID designed to measure the AIF for dPET scans through Monte Carlo simulations and B) develop a clinical data analysis chain to successfully separate the arterial component of a simulated AIF signal from the venous component.
Methods:
The NID was optimized by using an in-house Geant4-based software package. The sensitive volume of the NID consists of a band of 10 cm long and 1 mm in diameter scintillating fibers placed over a wrist phantom. The phantom was simulated as a cylinder, 10 cm long and 6.413 cm in diameter comprised of polyethylene with two holes placed through it to simulate the patient's radial artery and vein. This phantom design was chosen to match the wrist phantom used in our previous proof of concept work. Two geometries were simulated with different arrangements of scintillating fibers. The first design used a single layer of 64 fibers. The second used two layers, an inner layer with 29 fibers and an outer layer with 30 fibers. Four positron emitting radioisotopes were simulated: 18F, 11C, 15O and 68Ga with 100 million simulated decay events per run. The total and intrinsic efficiencies of both designs were calculated as well as the full width half max (FWHM) of the signal. In addition, contribution by the annihilation photons vs positrons to the signal was investigated. The results obtained from the two simulated detector models were compared. A clinical data analysis chain using an expectation maximization maximum likelihood algorithm was tested. This analysis chain will be used to separate arterial counts from the total signal.
Results:
The second NID design with two layers of scintillating fibers had a higher efficiency for all simulations with a maximum increase of 17% total efficiency for 11C simulation. All simulations had a significant annihilation photon contribution. The signal for 18F and 11C was almost entirely due to photons. The clinical data analysis chain was within 1% of the true value for 434 out of 440 trials. Further experimental studies to validate these simulations will be required.
Conclusions:
The design of the NID was optimized and its efficiency increased through Monte Carlo simulations. A clinical data analysis chain was successfully developed to separate the arterial component of an AIF signal from the venous component. The simulations show that the NID can be used to accurately measure the AIF non-invasively for dPET scans.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Dynamic positron emission tomography (dPET) is a nuclear medicine imaging technique providing functional images for organs of interest with applications in oncology, cardiology, and drug discovery. This technique requires the acquisition of the time-course arterial plasma activity concentration, called the arterial input function (AIF), which is conventionally acquired via arterial blood sampling.
Purpose:
The aim of this study was to A) optimize the geometry for a novel and cost efficient non-invasive detector called NID designed to measure the AIF for dPET scans through Monte Carlo simulations and B) develop a clinical data analysis chain to successfully separate the arterial component of a simulated AIF signal from the venous component.
Methods:
The NID was optimized by using an in-house Geant4-based software package. The sensitive volume of the NID consists of a band of 10 cm long and 1 mm in diameter scintillating fibers placed over a wrist phantom. The phantom was simulated as a cylinder, 10 cm long and 6.413 cm in diameter comprised of polyethylene with two holes placed through it to simulate the patient's radial artery and vein. This phantom design was chosen to match the wrist phantom used in our previous proof of concept work. Two geometries were simulated with different arrangements of scintillating fibers. The first design used a single layer of 64 fibers. The second used two layers, an inner layer with 29 fibers and an outer layer with 30 fibers. Four positron emitting radioisotopes were simulated: 18F, 11C, 15O and 68Ga with 100 million simulated decay events per run. The total and intrinsic efficiencies of both designs were calculated as well as the full width half max (FWHM) of the signal. In addition, contribution by the annihilation photons vs positrons to the signal was investigated. The results obtained from the two simulated detector models were compared. A clinical data analysis chain using an expectation maximization maximum likelihood algorithm was tested. This analysis chain will be used to separate arterial counts from the total signal.
Results:
The second NID design with two layers of scintillating fibers had a higher efficiency for all simulations with a maximum increase of 17% total efficiency for 11C simulation. All simulations had a significant annihilation photon contribution. The signal for 18F and 11C was almost entirely due to photons. The clinical data analysis chain was within 1% of the true value for 434 out of 440 trials. Further experimental studies to validate these simulations will be required.
Conclusions:
The design of the NID was optimized and its efficiency increased through Monte Carlo simulations. A clinical data analysis chain was successfully developed to separate the arterial component of an AIF signal from the venous component. The simulations show that the NID can be used to accurately measure the AIF non-invasively for dPET scans.
Carroll, Liam; Enger, Shirin A.
Second prize at the International Conference on Monte Carlo Techniques for Medical Applications award
2022.
@award{nokey,
title = {Second prize at the International Conference on Monte Carlo Techniques for Medical Applications },
author = {Liam Carroll and Shirin A. Enger},
year = {2022},
date = {2022-04-13},
urldate = {2022-04-13},
journal = {International Conference on Monte Carlo Techniques for Medical Applications },
abstract = {Introduction
Geant4[1] is a Monte Carlo toolkit that provides a flexible platform to design radiation transport simulations. This flexibility requires a high level of complexity when writing new user-codes. New users must undergo extensive training to begin writing useful simulations. The aim of this study was to develop a modular radiation simulation software package called MaRSS based on Geant4 user-code to serve as both an educational tool and as a simulation tool for medical radiation detector simulations.
Materials & Methods
MaRSS builds on Geant4 using Penelope electromagnetic physics models and cross-sections[2]. To give the users possibility to change simulation parameters without changing the source code, MaRSS is equipped with a set of messenger classes which are intercom modules provided by Geant4 to configure applications and provide user interactivity with the code. These messenger classes add additional user commands that can be used to add or remove volumes from the simulation geometry and associated sensitive detectors. The sensitive detectors are objects that Geant4 uses to save simulation results. A number of default volumes and detectors are included in MaRSS that can be used for the design of scintillating fiber-based radiation detectors. MaRSS adds to the existing Geant4 sensitive detector code by creating a new base class called RunSD that is inherited by all sensitive detector objects. RunSD is implemented such that the code needed to initialize a sensitive detector is included in two classes, normally, this code is spread out in several classes. A similar approach is taken with geometrical volumes. To validate MaRSS, range in water of positrons emitted from four radioisotopes commonly used for positron emission tomography was calculated and compared with published work: Fluorine-18 (18F), Carbon-11 (11C), Oxygen-15 (15O) and Gallium-68 (68Ga). A sphere with a radius of 1 m was filed with water. For each radioisotope, 100 million decay events were simulated originating at the center of the simulated water sphere. The resulting positrons were allowed to annihilate. Two energy cuts were simulated, 1 keV and 0.1 keV. Two histograms were created, one using the annihilation locations and another with the energy of the emitted positrons. Results were compared with published positron range values calculated with a PENELOPE[2]-based Monte Carlo software called PeneloPET [3], an analytical expression to estimate the range of positrons described by Cal-Gonzales et.al.[3], a simulation by Lehnert et. al. [4] written using GATE[5] and a separate Monte Carlo software written by Champion and Le Loirec[6] that directly simulates the formation of positronium in water to calculate positron range.
Results
Figure 1 shows the mean calculated positron ranges and calculated positron emission energies compared to literature values. Simulated positron energy means were within 1.8% of literature values. Simulated ranges were within 2% of GATE simulation[4].
References
[1] S. Agostinelli et al., “Geant4—a simulation toolkit,” Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip., vol. 506, no. 3, pp. 250–303, Jul. 2003.
[2] J. Baró, J. Sempau, J. M. Fernández-Varea, and F. Salvat, “PENELOPE: An algorithm for Monte Carlo simulation of the penetration and energy loss of electrons and positrons in matter,” Nucl. Inst. Methods Phys. Res. B, vol. 100, no. 1, pp. 31–46, May 1995.
[3] J. Cal-González et al., “Positron range estimations with PeneloPET,” Phys. Med. Biol., vol. 58, no. 15, pp. 5127–5152, 2013.
[4] W. Lehnert, M.-C. Gregoire, A. Reilhac, and S. R. Meikle, “Analytical positron range modelling in heterogeneous media for PET Monte Carlo simulation,” Phys. Med. Biol., vol. 56, no. 11, p. 3313, May 2011.
[5] D. Strul, G. Santin, D. Lazaro, V. Breton, and C. Morel, “GATE (geant4 application for tomographic emission): a PET/SPECT general-purpose simulation platform,” Nucl. Phys. B - Proc. Suppl., vol. 125, pp. 75–79, Sep. 2003.
[6] C. Champion and C. Le Loirec, “Positron follow-up in liquid water: II. Spatial and energetic study for the most important radioisotopes used in PET,” Phys. Med. Biol., vol. 52, no. 22, pp. 6605–6625, Nov. 2007.
},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Geant4[1] is a Monte Carlo toolkit that provides a flexible platform to design radiation transport simulations. This flexibility requires a high level of complexity when writing new user-codes. New users must undergo extensive training to begin writing useful simulations. The aim of this study was to develop a modular radiation simulation software package called MaRSS based on Geant4 user-code to serve as both an educational tool and as a simulation tool for medical radiation detector simulations.
Materials & Methods
MaRSS builds on Geant4 using Penelope electromagnetic physics models and cross-sections[2]. To give the users possibility to change simulation parameters without changing the source code, MaRSS is equipped with a set of messenger classes which are intercom modules provided by Geant4 to configure applications and provide user interactivity with the code. These messenger classes add additional user commands that can be used to add or remove volumes from the simulation geometry and associated sensitive detectors. The sensitive detectors are objects that Geant4 uses to save simulation results. A number of default volumes and detectors are included in MaRSS that can be used for the design of scintillating fiber-based radiation detectors. MaRSS adds to the existing Geant4 sensitive detector code by creating a new base class called RunSD that is inherited by all sensitive detector objects. RunSD is implemented such that the code needed to initialize a sensitive detector is included in two classes, normally, this code is spread out in several classes. A similar approach is taken with geometrical volumes. To validate MaRSS, range in water of positrons emitted from four radioisotopes commonly used for positron emission tomography was calculated and compared with published work: Fluorine-18 (18F), Carbon-11 (11C), Oxygen-15 (15O) and Gallium-68 (68Ga). A sphere with a radius of 1 m was filed with water. For each radioisotope, 100 million decay events were simulated originating at the center of the simulated water sphere. The resulting positrons were allowed to annihilate. Two energy cuts were simulated, 1 keV and 0.1 keV. Two histograms were created, one using the annihilation locations and another with the energy of the emitted positrons. Results were compared with published positron range values calculated with a PENELOPE[2]-based Monte Carlo software called PeneloPET [3], an analytical expression to estimate the range of positrons described by Cal-Gonzales et.al.[3], a simulation by Lehnert et. al. [4] written using GATE[5] and a separate Monte Carlo software written by Champion and Le Loirec[6] that directly simulates the formation of positronium in water to calculate positron range.
Results
Figure 1 shows the mean calculated positron ranges and calculated positron emission energies compared to literature values. Simulated positron energy means were within 1.8% of literature values. Simulated ranges were within 2% of GATE simulation[4].
References
[1] S. Agostinelli et al., “Geant4—a simulation toolkit,” Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip., vol. 506, no. 3, pp. 250–303, Jul. 2003.
[2] J. Baró, J. Sempau, J. M. Fernández-Varea, and F. Salvat, “PENELOPE: An algorithm for Monte Carlo simulation of the penetration and energy loss of electrons and positrons in matter,” Nucl. Inst. Methods Phys. Res. B, vol. 100, no. 1, pp. 31–46, May 1995.
[3] J. Cal-González et al., “Positron range estimations with PeneloPET,” Phys. Med. Biol., vol. 58, no. 15, pp. 5127–5152, 2013.
[4] W. Lehnert, M.-C. Gregoire, A. Reilhac, and S. R. Meikle, “Analytical positron range modelling in heterogeneous media for PET Monte Carlo simulation,” Phys. Med. Biol., vol. 56, no. 11, p. 3313, May 2011.
[5] D. Strul, G. Santin, D. Lazaro, V. Breton, and C. Morel, “GATE (geant4 application for tomographic emission): a PET/SPECT general-purpose simulation platform,” Nucl. Phys. B - Proc. Suppl., vol. 125, pp. 75–79, Sep. 2003.
[6] C. Champion and C. Le Loirec, “Positron follow-up in liquid water: II. Spatial and energetic study for the most important radioisotopes used in PET,” Phys. Med. Biol., vol. 52, no. 22, pp. 6605–6625, Nov. 2007.
Daoud, Youstina; Carroll, Liam; Enger, Shirin A.
A Radiation detector simulation toolkit for calculating the Arterial Input Function during Dynamic Positron Emission Tomography Proceedings Article
In: International Conference on Monte Carlo Techniques for Medical Applications, 2022.
@inproceedings{nokey,
title = {A Radiation detector simulation toolkit for calculating the Arterial Input Function during Dynamic Positron Emission Tomography},
author = {Youstina Daoud and Liam Carroll and Shirin A. Enger},
year = {2022},
date = {2022-04-10},
booktitle = {International Conference on Monte Carlo Techniques for Medical Applications},
abstract = {"Introduction
Dynamic Positron Emission Tomography (dPET) is a functional imaging modality that provides an accurate assessment of patients’ physiological activities and response to treatments such as cancer, cardiac diseases and Alzheimer’s disease. It requires the measurement of the time-course activity concentration of the positron emitting PET radioisotopes in the patient’s arterial plasma, called the Arterial Input Function (AIF). The gold standard measurement of the AIF requires blood samples from the patient during the dPET. In our group, we are developing a non-invasive radiation detector that, placed on a patient’s wrist during the dPET scan, measures the number of positrons and photons escaping the radial artery and calculates the AIF. We have also developed a Modular Radiation Simulation Software for detector simulations called MaRSS that allows the user to run a Geant4-based Monte Carlo simulation, to calculate the AIF. Using the Monte Carlo method, MaRSS simulates a radioactive source decay in the radial artery and scores the amount of radiation escaping the radial artery and reaching the detector placed on the simulated patient’s wrist phantom. The wrist phantom is designed as a cylinder containing 2 holes that simulates the radial artery and vein. The shape and the depth of the radial artery vary between patients and proper knowledge of the distance between the radial artery and the skin, as well as its surface area, is important to accurately design the wrist phantom. Therefore, our aim was to develop a graphical user interface (GUI) allowing the user to import 2D ultrasound scans of a patient’s wrist, provide tools to measure the distance between the radial artery and the skin as well as the radial artery’s surface area and to create the necessary input file to MaRSS. The GUI provides MaRSS with a patient specific and more accurate wrist phantom, providing a patient-specific and more accurate calculation of the AIF without knowledge of C++ or Geant4.
Materials & Methods
The GUI elements were implemented using the multi-platform application and widget toolkit Qt 5 [1]. The C++ library, VTK 8.2.0 [2] was integrated in the GUI, which enables the user to import and manipulate the 2D ultrasound images. The toolkit comprises a measurement tool, a visualization window, a detector tab, a radiation source tab and MaRSS which is its simulation tool. To create an accurate wrist phantom, three 2D – cross secctional ultrasound scans of the patient’s wrist at 2 cm, 4 cm and 6 cm from the wrist crease and 1 longitudinal scan along the radial artery may be acquired and saved in DICOM format. In our case the BK3000 ultrasound system is used. These scans are imported into the GUI by selecting the folder that contains the images. Using the measurement functionalities shown in the top left corner of Figure 1, the surface of the radial artery is measured by drawing an ellipse on the artery’s boundary, then the toolkit measures the surface of the drawn ellipse and displays it in the Measurement window. The artery’s depth is also measured and displayed by drawing a straight line between the artery’s boundary and the skin. Using the left and right arrows, the user can navigate through the selected folder and measure the artery’s surface and depth on the other scans. The top right corner of the GUI shown in Figure 1, illustrates a Detector tab and a Source tab. The Detector tab allows the user to import a detector in STL format and place it on the ultrasound scan to simulate different setups of the detector, this functionality is still under development and
International Conference on Monte Carlo Techniques for Medical Applications, 2022
is optional. The Source tab allows the user to add the radioactive source used during the dPET by entering its mass number and its atomic number. After completing the 3 mandatory steps : import of the scan, measurement of different parameters extracted from the scan and choice of the radioactive source, the user can run the simulation by clicking on Run Simulation in the Simulation menu. The toolkit runs the MaRSS and creates the wrist phantom using the artery’s surface and depth measured by the user, then starts the decay of the chosen source placed randomly inside the artery.
Results
This toolkit allows the user to import 2D ultrasound scans and measure the radial artery’s surface and depth along the wrist, choose the radioactive source from the Source drop-down menu and specify the detector position. An input file to the MaRSS is thus created providing the required information to simulate the wrist phantom, the source and the detector’s position in MaRSS. The Run Simulation tab displays the output of the simulation in the GUI making it the only used tool for setting up the simulation and viewing the results.
Discussion & Conclusions
This toolkit enables the user to run a Geant4 Monte Carlo based simulation for detector development applications in 3 easy steps, not requiring any programming knowledge.
References
[1] Blanchette J, Summerfield M. C++ GUI programming with Qt 4: Prentice Hall Professional; 2006.
[2] Schroeder WJ, Avila LS, Hoffman W. Visualizing with VTK: a tutorial. IEEE Computer graphics and applications. 2000;20(5):20-7.
Acknowledgements This research was undertaken,in part, thanks to funding from the Canada Research Chairs Program (grant # 252135) as well as CHRP (NSERC+CIHR grant 170620).
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Dynamic Positron Emission Tomography (dPET) is a functional imaging modality that provides an accurate assessment of patients’ physiological activities and response to treatments such as cancer, cardiac diseases and Alzheimer’s disease. It requires the measurement of the time-course activity concentration of the positron emitting PET radioisotopes in the patient’s arterial plasma, called the Arterial Input Function (AIF). The gold standard measurement of the AIF requires blood samples from the patient during the dPET. In our group, we are developing a non-invasive radiation detector that, placed on a patient’s wrist during the dPET scan, measures the number of positrons and photons escaping the radial artery and calculates the AIF. We have also developed a Modular Radiation Simulation Software for detector simulations called MaRSS that allows the user to run a Geant4-based Monte Carlo simulation, to calculate the AIF. Using the Monte Carlo method, MaRSS simulates a radioactive source decay in the radial artery and scores the amount of radiation escaping the radial artery and reaching the detector placed on the simulated patient’s wrist phantom. The wrist phantom is designed as a cylinder containing 2 holes that simulates the radial artery and vein. The shape and the depth of the radial artery vary between patients and proper knowledge of the distance between the radial artery and the skin, as well as its surface area, is important to accurately design the wrist phantom. Therefore, our aim was to develop a graphical user interface (GUI) allowing the user to import 2D ultrasound scans of a patient’s wrist, provide tools to measure the distance between the radial artery and the skin as well as the radial artery’s surface area and to create the necessary input file to MaRSS. The GUI provides MaRSS with a patient specific and more accurate wrist phantom, providing a patient-specific and more accurate calculation of the AIF without knowledge of C++ or Geant4.
Materials & Methods
The GUI elements were implemented using the multi-platform application and widget toolkit Qt 5 [1]. The C++ library, VTK 8.2.0 [2] was integrated in the GUI, which enables the user to import and manipulate the 2D ultrasound images. The toolkit comprises a measurement tool, a visualization window, a detector tab, a radiation source tab and MaRSS which is its simulation tool. To create an accurate wrist phantom, three 2D – cross secctional ultrasound scans of the patient’s wrist at 2 cm, 4 cm and 6 cm from the wrist crease and 1 longitudinal scan along the radial artery may be acquired and saved in DICOM format. In our case the BK3000 ultrasound system is used. These scans are imported into the GUI by selecting the folder that contains the images. Using the measurement functionalities shown in the top left corner of Figure 1, the surface of the radial artery is measured by drawing an ellipse on the artery’s boundary, then the toolkit measures the surface of the drawn ellipse and displays it in the Measurement window. The artery’s depth is also measured and displayed by drawing a straight line between the artery’s boundary and the skin. Using the left and right arrows, the user can navigate through the selected folder and measure the artery’s surface and depth on the other scans. The top right corner of the GUI shown in Figure 1, illustrates a Detector tab and a Source tab. The Detector tab allows the user to import a detector in STL format and place it on the ultrasound scan to simulate different setups of the detector, this functionality is still under development and
International Conference on Monte Carlo Techniques for Medical Applications, 2022
is optional. The Source tab allows the user to add the radioactive source used during the dPET by entering its mass number and its atomic number. After completing the 3 mandatory steps : import of the scan, measurement of different parameters extracted from the scan and choice of the radioactive source, the user can run the simulation by clicking on Run Simulation in the Simulation menu. The toolkit runs the MaRSS and creates the wrist phantom using the artery’s surface and depth measured by the user, then starts the decay of the chosen source placed randomly inside the artery.
Results
This toolkit allows the user to import 2D ultrasound scans and measure the radial artery’s surface and depth along the wrist, choose the radioactive source from the Source drop-down menu and specify the detector position. An input file to the MaRSS is thus created providing the required information to simulate the wrist phantom, the source and the detector’s position in MaRSS. The Run Simulation tab displays the output of the simulation in the GUI making it the only used tool for setting up the simulation and viewing the results.
Discussion & Conclusions
This toolkit enables the user to run a Geant4 Monte Carlo based simulation for detector development applications in 3 easy steps, not requiring any programming knowledge.
References
[1] Blanchette J, Summerfield M. C++ GUI programming with Qt 4: Prentice Hall Professional; 2006.
[2] Schroeder WJ, Avila LS, Hoffman W. Visualizing with VTK: a tutorial. IEEE Computer graphics and applications. 2000;20(5):20-7.
Acknowledgements This research was undertaken,in part, thanks to funding from the Canada Research Chairs Program (grant # 252135) as well as CHRP (NSERC+CIHR grant 170620).
"
Martinez, Victor Daniel Diaz; Carroll, Liam; Enger, Shirin A.
Monte Carlo Simulation of the 224Ra Decay Chain and the Diffusion of 220Rn for Diffusing Alpha-Emitters Radiotherapy Proceedings Article
In: MEDICAL PHYSICS, pp. E828–E828, WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA 2022.
@inproceedings{martinez2022monte,
title = {Monte Carlo Simulation of the 224Ra Decay Chain and the Diffusion of 220Rn for Diffusing Alpha-Emitters Radiotherapy},
author = {Victor Daniel Diaz Martinez and Liam Carroll and Shirin A. Enger},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
booktitle = {MEDICAL PHYSICS},
volume = {49},
number = {6},
pages = {E828--E828},
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Carroll, Liam; Enger, Shirin A.
Monte Carlo Simulations of a Non-Invasive Positron Detector to Measure the Arterial Input Function for Dynamic PET Proceedings Article
In: Journal of Physics: Conference Series, pp. 012005, IOP Publishing 2022.
@inproceedings{carroll2022monte,
title = {Monte Carlo Simulations of a Non-Invasive Positron Detector to Measure the Arterial Input Function for Dynamic PET},
author = {Liam Carroll and Shirin A. Enger},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
booktitle = {Journal of Physics: Conference Series},
volume = {2167},
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pages = {012005},
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Carroll, Liam; Enger, Shirin A.
Non-invasive measurement of the arterial input function for dynamic positron emission tomography: Simulation of clinical workflow Proceedings Article
In: MEDICAL PHYSICS, pp. 5643–5644, WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA 2022.
@inproceedings{carroll2022non,
title = {Non-invasive measurement of the arterial input function for dynamic positron emission tomography: Simulation of clinical workflow},
author = {Liam Carroll and Shirin A. Enger},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
booktitle = {MEDICAL PHYSICS},
volume = {49},
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organization = {WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA},
keywords = {},
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}
Daoud, Youstina; Carroll, Liam; Enger, Shrin A.
PO-1617 Mapping of the human wrist to develop a non-invasive radiation detector for Dynamic PET application Journal Article
In: Radiotherapy and Oncology, vol. 170, pp. S1405–S1406, 2022.
@article{daoud2022po,
title = {PO-1617 Mapping of the human wrist to develop a non-invasive radiation detector for Dynamic PET application},
author = {Youstina Daoud and Liam Carroll and Shrin A. Enger},
year = {2022},
date = {2022-01-01},
urldate = {2022-01-01},
journal = {Radiotherapy and Oncology},
volume = {170},
pages = {S1405--S1406},
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pubstate = {published},
tppubtype = {article}
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Carroll, Liam; Enger, Shirin A
Simulation of a novel, non-invasive radiation detector to measure the arterial input function for dynamic PET Journal Article
In: Medical Physics, 2022.
@article{carroll2022simulation,
title = {Simulation of a novel, non-invasive radiation detector to measure the arterial input function for dynamic PET},
author = {Liam Carroll and Shirin A Enger},
year = {2022},
date = {2022-01-01},
journal = {Medical Physics},
publisher = {Wiley Online Library},
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pubstate = {published},
tppubtype = {article}
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Martinez, Victor Daniel Diaz; Cyr, Melodie; Slobodan, Devic; Tomic, Nada; Lewis, David F; Enger, Shirin A.
Use of the Monte Carlo Method to Relate GAFCHROMIC (R) EBT3 Film Response to Absorbed Dose for Alpha Particle Dosimetry Proceedings Article
In: MEDICAL PHYSICS, pp. 5653–5653, WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA 2022.
@inproceedings{martinez2022use,
title = {Use of the Monte Carlo Method to Relate GAFCHROMIC (R) EBT3 Film Response to Absorbed Dose for Alpha Particle Dosimetry},
author = {Victor Daniel Diaz Martinez and Melodie Cyr and Devic Slobodan and Nada Tomic and David F Lewis and Shirin A. Enger},
year = {2022},
date = {2022-01-01},
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Bian, Jingyi; Duran, Juan; Shin, Wook-Geun; Ramos-Mendez, Jose; Childress, Lilian; Sankey, Jack; Seuntjens, Jan; Enger, Shirin A.
Update of the GEANT4-DNA Software for Simulation of Radiation Chemical Yield for Reactive Water Radiolysis Species at Different Temperature and PH Proceedings Article
In: MEDICAL PHYSICS, pp. E911–E912, WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA 2022.
@inproceedings{bian2022update,
title = {Update of the GEANT4-DNA Software for Simulation of Radiation Chemical Yield for Reactive Water Radiolysis Species at Different Temperature and PH},
author = {Jingyi Bian and Juan Duran and Wook-Geun Shin and Jose Ramos-Mendez and Lilian Childress and Jack Sankey and Jan Seuntjens and Shirin A. Enger},
year = {2022},
date = {2022-01-01},
booktitle = {MEDICAL PHYSICS},
volume = {49},
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2021
Bui, Alaina; Childress, Lilian; Sankey, Jack; Seuntjens, Jan; Enger, Shirin A.
Effect of Incoming Particle Energy and Ionization Cluster Size on the G-value of Hydrated Electrons Presentation
AAPM 63rd Annual Meeting, 25.07.2021.
@misc{Bui2021,
title = {Effect of Incoming Particle Energy and Ionization Cluster Size on the G-value of Hydrated Electrons},
author = {Alaina Bui and Lilian Childress and Jack Sankey and Jan Seuntjens and Shirin A. Enger},
year = {2021},
date = {2021-07-25},
howpublished = {AAPM 63rd Annual Meeting},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Thibodeau-Antonacci, Alana; Jafarzadeh, Hossein; Carroll, Liam; Weishaupt, Luca L.
Mitacs Globalink Research Award award
2021.
@award{Thibodeau-Antonacci2021c,
title = {Mitacs Globalink Research Award},
author = {Alana Thibodeau-Antonacci and Hossein Jafarzadeh and Liam Carroll and Luca L. Weishaupt},
url = {https://www.mitacs.ca/en/programs/globalink/globalink-research-award},
year = {2021},
date = {2021-07-01},
urldate = {2021-07-01},
organization = {MITACS},
abstract = {The Mitacs Globalink Research Award (GRA) supports research collaborations between Canada and select partner organizations and eligible countries and regions. It was awarded to Alana Thibodeau-Antonacci, Hossein Jafarzadeh, Liam Carroll and Luca L. Weishaupt.
Under the joint supervision of a home and host professor, successful senior undergraduate students, graduate students, as well as postdoctoral fellows will receive a $6,000 research award to conduct a 12- to 24-week research project in the other country. Awards are offered in partnership with Mitacs’s Canadian academic partners (and, in some cases, with Mitacs’s international partners) and are subject to available funding. },
howpublished = {Mitacs},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Under the joint supervision of a home and host professor, successful senior undergraduate students, graduate students, as well as postdoctoral fellows will receive a $6,000 research award to conduct a 12- to 24-week research project in the other country. Awards are offered in partnership with Mitacs’s Canadian academic partners (and, in some cases, with Mitacs’s international partners) and are subject to available funding.
Bui, Alaina; Bekerat, Hamed; Enger, Shirin A.
Film measurements for verification of dose results in hydrated electron dosimetry Presentation
COMP Virtual Scientific Meeting, 25.06.2021.
@misc{Bui2021b,
title = {Film measurements for verification of dose results in hydrated electron dosimetry},
author = {Alaina Bui and Hamed Bekerat and Shirin A. Enger},
year = {2021},
date = {2021-06-25},
howpublished = {COMP Virtual Scientific Meeting},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Bui, Alaina; Childress, Lilian; Sankey, Jack; Seuntjens, Jan; Enger, Shirin A.
Effect of incoming particle energy, cluster size, LET, and depth in water on the G-value of hydrated electrons Presentation
COMP Virtual Scientific Meeting, 22.06.2021.
@misc{Bui2021c,
title = {Effect of incoming particle energy, cluster size, LET, and depth in water on the G-value of hydrated electrons},
author = {Alaina Bui and Lilian Childress and Jack Sankey and Jan Seuntjens and Shirin A. Enger },
year = {2021},
date = {2021-06-22},
urldate = {2021-06-22},
howpublished = {COMP Virtual Scientific Meeting},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
2020
Bui, Alaina; Childress, Lilian; Sankey, Jack; Enger, Shirin A.
Developing a hydrated electron dosimeter and determining the G-value of hydrated electrons Presentation
Association Québécoise des Physicien(ne)s Médicaux Cliniques, 05.11.2020.
@misc{Bui2020,
title = {Developing a hydrated electron dosimeter and determining the G-value of hydrated electrons},
author = {Alaina Bui and Lilian Childress and Jack Sankey and Shirin A. Enger},
year = {2020},
date = {2020-11-05},
howpublished = {Association Québécoise des Physicien(ne)s Médicaux Cliniques},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Turgeon, Vincent; Morcos, Marc; Antaki, Majd; Enger, Shirin A.
Impact of choices in dosimetric calculation method for high dose rate brachytherapy of breast cancer Presentation
Radiotherapy and Oncology, 01.11.2020, ISSN: 0167-8140, 1879-0887.
@misc{Turgeon2020,
title = {Impact of choices in dosimetric calculation method for high dose rate brachytherapy of breast cancer},
author = {Vincent Turgeon and Marc Morcos and Majd Antaki and Shirin A. Enger},
url = {https://www.thegreenjournal.com/article/S0167-8140(21)01974-5/fulltext},
doi = {10.1016/S0167-8140(21)01974-5},
issn = {0167-8140, 1879-0887},
year = {2020},
date = {2020-11-01},
abstract = {www.thegreenjournal.com},
howpublished = {Radiotherapy and Oncology},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Carroll, Liam; Croteau, Etienne; Kertzscher, Gustavo; Sarrhini, Otman; Turgeon, Vincent; Lecomte, Roger; Enger, Shirin A.
In: Physica medica: PM: an international journal devoted to the applications of physics to medicine and biology: official journal of the Italian Association of Biomedical Physics (AIFB), vol. 76, pp. 92–99, 2020, ISSN: 1724-191X.
@article{carroll_cross-validation_2020,
title = {Cross-validation of a non-invasive positron detector to measure the arterial input function for pharmacokinetic modelling in dynamic positron emission tomography},
author = {Liam Carroll and Etienne Croteau and Gustavo Kertzscher and Otman Sarrhini and Vincent Turgeon and Roger Lecomte and Shirin A. Enger},
doi = {10.1016/j.ejmp.2020.06.009},
issn = {1724-191X},
year = {2020},
date = {2020-08-01},
journal = {Physica medica: PM: an international journal devoted to the applications of physics to medicine and biology: official journal of the Italian Association of Biomedical Physics (AIFB)},
volume = {76},
pages = {92--99},
abstract = {Kinetic modeling of positron emission tomography (PET) data can assess index rate of uptake, metabolism and predict disease progression more accurately than conventional static PET. However, it requires knowledge of the time-course of the arterial blood radioactivity concentration, called the arterial input function (AIF). The gold standard to acquire the AIF is by invasive means. The purpose of this study was to validate a previously developed dual readout scintillating fiber-based non-invasive positron detector, hereinafter called non-invasive detector (NID), developed to determine the AIF for dynamic PET measured from the human radial artery. The NID consisted of a 3 m long plastic scintillating fiber with each end coupled to a 5 m long transmission fiber followed by a silicon photomultiplier. The scintillating fiber was enclosed inside the grooves of a plastic cylindrical shell. Two sets of experiments were performed to test the NID against a previously validated microfluidic positron detector. A closed-loop microfluidic system combined with a wrist phantom was used. During the first experiment, the three PET radioisotopes 18F, 11C and 68Ga were tested. After optimizing the detector, a second series of tests were performed using only 18F and 11C. The maximum pulse amplitude to electronic noise ratio was 52 obtained with 11C. Linear regressions showed a linear relation between the two detectors. These preliminary results show that the NID can accurately detect positrons from a patient's wrist and has the potential to non-invasively measure the AIF during a dynamic PET scan. The accuracy of these measurements needs to be determined.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Carroll, Liam
First prize for best presentation at the congrès annuel de l'AQPMC award
2020.
@award{Carroll2020b,
title = {First prize for best presentation at the congrès annuel de l'AQPMC},
author = {Liam Carroll},
year = {2020},
date = {2020-07-01},
urldate = {2020-07-01},
organization = {Congrès Annuel de l'AQPMC},
abstract = {Nous tenons particulièrement à féliciter Liam Carroll, étudiant à McGill Medical Physics qui a remporté le prix de la meilleure présentation.},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Carroll, Liam
Excellence Award from Department of Biological and Biomedical Engineering award
2020.
@award{Carroll2020,
title = {Excellence Award from Department of Biological and Biomedical Engineering},
author = {Liam Carroll},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
organization = {McGill University},
school = {Bioengineering and Biomedical Engineering Program},
abstract = {The award recognizes excellent performance in the PhD Program of the BBME/BME graduate program. The selection is based on a combination of overall excellence, performance in the program, grades, progress in project and publications. },
howpublished = {Department of Biological and Biomedical Engineering},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
2019
Mégrourèche, Julien; Childress, Lilian; Sankey, Jack; Bui, Alaina; Enger, Shirin A.
Development of an in-vivo radiation dosimeter for radiotherapy. Winner of the best in Physics Award. award
2019.
@award{Mégrourèche2019,
title = {Development of an in-vivo radiation dosimeter for radiotherapy. Winner of the best in Physics Award.},
author = {Julien Mégrourèche and Lilian Childress and Jack Sankey and Alaina Bui and Shirin A. Enger},
year = {2019},
date = {2019-10-01},
urldate = {2019-10-01},
howpublished = {Radiation Association of Radiation Oncology (CARO)},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Turgeon, Vincent; Kertzscher, Gustavo; Carroll, Liam; Hopewell, Robert; Massarweh, Gassan; Enger, Shirin A.
Characterization of scintillating fibers for use as positron detector in positron emission tomography Journal Article
In: Physica medica: PM: an international journal devoted to the applications of physics to medicine and biology: official journal of the Italian Association of Biomedical Physics (AIFB), vol. 65, pp. 114–120, 2019, ISSN: 1724-191X.
@article{turgeon_characterization_2019,
title = {Characterization of scintillating fibers for use as positron detector in positron emission tomography},
author = {Vincent Turgeon and Gustavo Kertzscher and Liam Carroll and Robert Hopewell and Gassan Massarweh and Shirin A. Enger},
doi = {10.1016/j.ejmp.2019.08.009},
issn = {1724-191X},
year = {2019},
date = {2019-09-01},
journal = {Physica medica: PM: an international journal devoted to the applications of physics to medicine and biology: official journal of the Italian Association of Biomedical Physics (AIFB)},
volume = {65},
pages = {114--120},
abstract = {PURPOSE: Manual and automatic blood sampling at different time intervals is considered the gold standard to determine the arterial input function (AIF) in dynamic positron emission tomography (PET). However, blood sampling is characterized by poor time resolution and is an invasive procedure. The aim of this study was to characterize the scintillating fibers used to develop a non-invasive positron detector.
METHODS: The detector consists of a scintillating fiber coupled at each end to transmission fiber-optic cables that are connected to photo multiplier tubes in a dual readout setup. The detector is designed to be wrapped around the wrist of the patient undergoing dynamic PET. The attenuation length and bending losses were measured with excitation from gamma radiation (137Cs) and ultraviolet (UV) light. The response to positron-emitting radio-tracers was evaluated with 18F and 11C.
RESULTS: The attenuation length for a 3.0 m and 1.5 m long scintillating fiber both coincides with the attenuation length given by the manufacturer when excited with the 137Cs source, but not with the UV source due to the differences in scintillation mechanisms. The bending losses are smaller than the measurement uncertainty for the 137Cs source irradiation, and increase when the bending radius decrease for the UV source irradiation. The signal-to-noise ratio for 18F and 11C solutions are 1.98 and 22.54 respectively. The measured decay constant of 11C agrees with its characteristic value.
CONCLUSION: The performed measurements in the dual readout configuration suggest that scintillating fibers may be suitable to determine the AIF non-invasively.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
METHODS: The detector consists of a scintillating fiber coupled at each end to transmission fiber-optic cables that are connected to photo multiplier tubes in a dual readout setup. The detector is designed to be wrapped around the wrist of the patient undergoing dynamic PET. The attenuation length and bending losses were measured with excitation from gamma radiation (137Cs) and ultraviolet (UV) light. The response to positron-emitting radio-tracers was evaluated with 18F and 11C.
RESULTS: The attenuation length for a 3.0 m and 1.5 m long scintillating fiber both coincides with the attenuation length given by the manufacturer when excited with the 137Cs source, but not with the UV source due to the differences in scintillation mechanisms. The bending losses are smaller than the measurement uncertainty for the 137Cs source irradiation, and increase when the bending radius decrease for the UV source irradiation. The signal-to-noise ratio for 18F and 11C solutions are 1.98 and 22.54 respectively. The measured decay constant of 11C agrees with its characteristic value.
CONCLUSION: The performed measurements in the dual readout configuration suggest that scintillating fibers may be suitable to determine the AIF non-invasively.
Mégrourèche, Julien; Childress, Lilian; Sankey, Jack; Bui, Alaina; Enger, Shirin A.
Development of a hydrated electron dosimeter for in vivo applications in radiotherapy: A proof of concept. Winner of the J.R. Cunningham Young Investigators Award award
2019.
@award{Mégrourèche2019b,
title = {Development of a hydrated electron dosimeter for in vivo applications in radiotherapy: A proof of concept. Winner of the J.R. Cunningham Young Investigators Award},
author = {Julien Mégrourèche and Lilian Childress and Jack Sankey and Alaina Bui and Shirin A. Enger },
year = {2019},
date = {2019-09-01},
urldate = {2019-09-01},
howpublished = {Canadian Organization of Medical Physicists (COMP)},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Carroll, Liam; Croteau, Etienne; Kertzscher, Gustavo; Sarrhini, Otman; Lecomte, Roger; Enger, Shirin A.
Validation of a Non-Invasive Positron Detector for Use with Dynamic PET Under Clinical Conditions Presentation
AAPM 61st Annual Meeting, 14.07.2019.
@misc{nokey,
title = {Validation of a Non-Invasive Positron Detector for Use with Dynamic PET Under Clinical Conditions},
author = {Liam Carroll and Etienne Croteau and Gustavo Kertzscher and Otman Sarrhini and Roger Lecomte and Shirin A. Enger},
year = {2019},
date = {2019-07-14},
howpublished = {AAPM 61st Annual Meeting},
keywords = {},
pubstate = {published},
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}
Mégrourèche, Julien; Childress, Lilian; Sankey, Jack; Enger, Shirin A.
Development of a hydrated electron dosimeter for radiotherapy applications Presentation
AAPM 61st Annual Meeting, 14.07.2019.
@misc{Mégrourèche2019d,
title = {Development of a hydrated electron dosimeter for radiotherapy applications},
author = {Julien Mégrourèche and Lilian Childress and Jack Sankey and Shirin A. Enger},
year = {2019},
date = {2019-07-14},
howpublished = {AAPM 61st Annual Meeting},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Carroll, Liam; Croteau, Etienne; Kertzscher, Gustavo; Sarrhini, Otman; Lecomte, Roger; Enger, Shirin A.
Cross-validation of a non-invasive positron detector to measure the arterial input function for pharmacokinetic modelling in dynamic PET imaging Presentation
Society of Nuclear Medicine and Molecular Imaging (SNMMI), 24.06.2019.
@misc{Carroll2019c,
title = {Cross-validation of a non-invasive positron detector to measure the arterial input function for pharmacokinetic modelling in dynamic PET imaging},
author = {Liam Carroll and Etienne Croteau and Gustavo Kertzscher and Otman Sarrhini and Roger Lecomte and Shirin A. Enger},
year = {2019},
date = {2019-06-24},
howpublished = {Society of Nuclear Medicine and Molecular Imaging (SNMMI)},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Carroll, Liam; Kertzscher, Gustavo; Enger, Shirin A.
Winners of the Marika Zelenka Roy Innovation Prize award
2019.
@award{Carroll2019b,
title = {Winners of the Marika Zelenka Roy Innovation Prize},
author = {Liam Carroll and Gustavo Kertzscher and Shirin A. Enger},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
organization = {McGill University},
abstract = {(50 k CAD) at McGill University Clinical Innovation Competition for the detector BetaSense (A non-invasive positron detector to measure the arterial input function for pharmacokinetic modelling in dynamic positron emission tomography imaging). },
howpublished = {McGill University Clinical Innovation Competition},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Carroll, Liam; Kertzscher, Gustavo; Enger, Shirin A.
Winners of the Centech propulsion program award
2019.
@award{Carroll2019,
title = {Winners of the Centech propulsion program},
author = {Liam Carroll and Gustavo Kertzscher and Shirin A. Enger},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
organization = {Centech},
abstract = {Two years’ business incubator, (50 k CAD) + access to consulting firms to build a commercial version of BetaSense that can be used in a clinical environment for patient measurements. },
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Mégrourèche, Julien; Bui, Alaina; Sankey, Jack; Childress, Lilian; Enger, Shirin A.
2nd prize in the Young Investigator Competition award
2019.
@award{Mégrourèche2019c,
title = {2nd prize in the Young Investigator Competition},
author = {Julien Mégrourèche and Alaina Bui and Jack Sankey and Lilian Childress and Shirin A. Enger},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
organization = {McGill University Health Center},
abstract = {Development of a Hydrated Electron Dosimeter for Radiotherapy
Applications: A Proof of Concept. 2nd prize in the Young Investigator Competition award at the Research Institute of McGill University Health Center, Cancer Research program.},
howpublished = {Research Institute of McGill University Health Center},
keywords = {},
pubstate = {published},
tppubtype = {award}
}
Applications: A Proof of Concept. 2nd prize in the Young Investigator Competition award at the Research Institute of McGill University Health Center, Cancer Research program.
2018
Turgeon, Vincent; Kertzscher, Gustavo; Enger, Shirin A.
Best abstracts to compete in the young investigator symposium Miscellaneous
CARO-COMP. Joint Scientific Meeting, Young Investigator Symposium, 2018.
@misc{Turgeon2018,
title = {Best abstracts to compete in the young investigator symposium},
author = {Vincent Turgeon and Gustavo Kertzscher and Shirin A. Enger},
year = {2018},
date = {2018-09-12},
abstract = {Non-invasive Positron Detector for the Monitoring of the Arterial Input Function in PET.
This abstract was selected as one of the best abstracts to compete in this year’s young investigator symposium, CARO-COMP.},
howpublished = {CARO-COMP. Joint Scientific Meeting, Young Investigator Symposium},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
This abstract was selected as one of the best abstracts to compete in this year’s young investigator symposium, CARO-COMP.
Turgeon, Vincent; Kertzscher, Gustavo; Enger, Shirin A.
Non-invasive Positron Detector for the Monitoring of the Arterial Input Function in PET Presentation
CARO-COMP-CAMRT 2018 Joint Scientific Meeting, Young Investigator Symposium, 12.09.2018.
@misc{Turgeon2018b,
title = {Non-invasive Positron Detector for the Monitoring of the Arterial Input Function in PET},
author = {Vincent Turgeon and Gustavo Kertzscher and Shirin A. Enger},
year = {2018},
date = {2018-09-12},
howpublished = {CARO-COMP-CAMRT 2018 Joint Scientific Meeting, Young Investigator Symposium},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Turgeon, Vincent; Kertzscher, Gustavo; Enger, Shirin A.
Non-Invasive Positron Detector to Monitor the Input Function in PET Presentation
AAPM Annual meeting, 29.07.2018.
@misc{nokey,
title = {Non-Invasive Positron Detector to Monitor the Input Function in PET},
author = {Vincent Turgeon and Gustavo Kertzscher and Shirin A. Enger},
year = {2018},
date = {2018-07-29},
howpublished = {AAPM Annual meeting},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Turgeon, Vincent; Kertzscher, Gustavo; Enger, Shirin A.
Enabling Dynamic PET Imaging Beyond Academic Centers Presentation
The Cancer Research Program Research day at RI-MUHC, 22.05.2018.
@misc{Turgeon2018c,
title = {Enabling Dynamic PET Imaging Beyond Academic Centers},
author = {Vincent Turgeon and Gustavo Kertzscher and Shirin A. Enger},
year = {2018},
date = {2018-05-22},
howpublished = {The Cancer Research Program Research day at RI-MUHC},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}