The purpose of this work was to evaluate the effect of a strong, transverse magnetic field on the severity of radiation-induced lung damage in mice. This data can be used to support the safe clinical implementation of MRI-guided radiation therapy systems.
Monte Carlo simulations and EBT3 film measurements were used to determine an irradiator and magnetic field strength that would produce magnetic-field-induced dose perturbations in mice that were comparable to those seen in human simulations. We developed an irradiation scheme for C57L/J mice, which included irradiating mice to the whole thorax in a 3D-printed holder with parallel-opposed Co-60 beams. We developed non-invasive assays for evaluating the extent of radiation-induced lung injury, including a respiratory rate measurement technique and techniques for measuring lung damage on cone-beam CTs. We showed that these assays were correlated to survival, the ultimate predictor of radiation-induced lung injury.
The mice were irradiated to 9.0, 10.0, 10.5, 11.0, 12.0, or 13.0 Gy between the poles of an electromagnet in a 1.5 T field (n=60) or 0 T field (n=60). Twenty control mice did not receive radiation. Survival, respiratory rate measurements, and free-breathing cone-beam CT measurements (lung density and healthy lung volume) were used to assess the severity of radiation-induced pneumonitis.
Cox regression showed that dose was a much higher predictor of survival than magnetic field strength. The presence of a transverse 1.5 T field during irradiation had little to no effect on survival for each of the dose groups. The 1.5 T field did, however, have an effect on the severity of radiation-induced lung injury, as measured by respiratory rate, lung density, and lung volume.
The results of these studies suggest that it is possible to reduce magnetic-field-induced dose perturbations by using parallel-opposed fields, and in this case the impact of a strong, transverse magnetic field on survival would be expected to be insignificant. However, our results also suggest that there could be some impact on the severity of radiation-induced lung damage, though that impact is likely small.
","abstract_html":"<p>The purpose of this work was to evaluate the effect of a strong, transverse magnetic field on the severity of radiation-induced lung damage in mice. This data can be used to support the safe clinical implementation of MRI-guided radiation therapy systems.</p> <p>Monte Carlo simulations and EBT3 film measurements were used to determine an irradiator and magnetic field strength that would produce magnetic-field-induced dose perturbations in mice that were comparable to those seen in human simulations. We developed an irradiation scheme for C57L/J mice, which included irradiating mice to the whole thorax in a 3D-printed holder with parallel-opposed Co-60 beams. We developed non-invasive assays for evaluating the extent of radiation-induced lung injury, including a respiratory rate measurement technique and techniques for measuring lung damage on cone-beam CTs. We showed that these assays were correlated to survival, the ultimate predictor of radiation-induced lung injury.</p> <p>The mice were irradiated to 9.0, 10.0, 10.5, 11.0, 12.0, or 13.0 Gy between the poles of an electromagnet in a 1.5 T field (n=60) or 0 T field (n=60). Twenty control mice did not receive radiation. Survival, respiratory rate measurements, and free-breathing cone-beam CT measurements (lung density and healthy lung volume) were used to assess the severity of radiation-induced pneumonitis.</p> <p>Cox regression showed that dose was a much higher predictor of survival than magnetic field strength. The presence of a transverse 1.5 T field during irradiation had little to no effect on survival for each of the dose groups. The 1.5 T field did, however, have an effect on the severity of radiation-induced lung injury, as measured by respiratory rate, lung density, and lung volume.</p> <p>The results of these studies suggest that it is possible to reduce magnetic-field-induced dose perturbations by using parallel-opposed fields, and in this case the impact of a strong, transverse magnetic field on survival would be expected to be insignificant. However, our results also suggest that there could be some impact on the severity of radiation-induced lung damage, though that impact is likely small.</p>","abstract_has_math":false,"creators":["Rubinstein, Ashley E","orcid.org/0000-0003-0221-4603
"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation (PhD)","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Laurence E. Court","David S. Followill","Adam D. Melancon"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-08-01T07:00:00Z","date_published":"2017-08-01T07:00:00Z","updated_at":"2026-07-24T05:50:02Z","subjects":["MRIgRT","dose perturbations","mice","radiation-induced pneumonitis","MCNP6","magnetic-field-induced dose effects","MRI-guided radiation therapy","Biophysics","Medical Biophysics","Medicine and Health Sciences","Other Physics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.library.tmc.edu/utgsbs_dissertations/786","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Laurence E. Court","David S. Followill","Adam D. Melancon"]},{"key":"dc:creator","label":"Author","values":["Rubinstein, Ashley E","orcid.org/0000-0003-0221-4603
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Monte Carlo simulations and EBT3 film measurements were used to determine an irradiator and magnetic field strength that would produce magnetic-field-induced dose perturbations in mice that were comparable to those seen in human simulations. We developed an irradiation scheme for C57L/J mice, which included irradiating mice to the whole thorax in a 3D-printed holder with parallel-opposed Co-60 beams. We developed non-invasive assays for evaluating the extent of radiation-induced lung injury, including a respiratory rate measurement technique and techniques for measuring lung damage on cone-beam CTs. We showed that these assays were correlated to survival, the ultimate predictor of radiation-induced lung injury.
The mice were irradiated to 9.0, 10.0, 10.5, 11.0, 12.0, or 13.0 Gy between the poles of an electromagnet in a 1.5 T field (n=60) or 0 T field (n=60). Twenty control mice did not receive radiation. Survival, respiratory rate measurements, and free-breathing cone-beam CT measurements (lung density and healthy lung volume) were used to assess the severity of radiation-induced pneumonitis.
Cox regression showed that dose was a much higher predictor of survival than magnetic field strength. The presence of a transverse 1.5 T field during irradiation had little to no effect on survival for each of the dose groups. The 1.5 T field did, however, have an effect on the severity of radiation-induced lung injury, as measured by respiratory rate, lung density, and lung volume.
The results of these studies suggest that it is possible to reduce magnetic-field-induced dose perturbations by using parallel-opposed fields, and in this case the impact of a strong, transverse magnetic field on survival would be expected to be insignificant. However, our results also suggest that there could be some impact on the severity of radiation-induced lung damage, though that impact is likely small.
"]},{"key":"dc:title","label":"Title","values":["A Preclinical Study of Radiation-Induced Lung to xicity When Irradiating In A Strong Magnetic Field"]}]}],"canonical_facts":{"dc:contributor":["Laurence E. Court","David S. Followill","Adam D. Melancon"],"dc:creator":["Rubinstein, Ashley E","orcid.org/0000-0003-0221-4603
"],"dc:date.available":["2017-07-24T07:00:00Z"],"dc:description.abstract":["The purpose of this work was to evaluate the effect of a strong, transverse magnetic field on the severity of radiation-induced lung damage in mice. This data can be used to support the safe clinical implementation of MRI-guided radiation therapy systems.
Monte Carlo simulations and EBT3 film measurements were used to determine an irradiator and magnetic field strength that would produce magnetic-field-induced dose perturbations in mice that were comparable to those seen in human simulations. We developed an irradiation scheme for C57L/J mice, which included irradiating mice to the whole thorax in a 3D-printed holder with parallel-opposed Co-60 beams. We developed non-invasive assays for evaluating the extent of radiation-induced lung injury, including a respiratory rate measurement technique and techniques for measuring lung damage on cone-beam CTs. We showed that these assays were correlated to survival, the ultimate predictor of radiation-induced lung injury.
The mice were irradiated to 9.0, 10.0, 10.5, 11.0, 12.0, or 13.0 Gy between the poles of an electromagnet in a 1.5 T field (n=60) or 0 T field (n=60). Twenty control mice did not receive radiation. Survival, respiratory rate measurements, and free-breathing cone-beam CT measurements (lung density and healthy lung volume) were used to assess the severity of radiation-induced pneumonitis.
Cox regression showed that dose was a much higher predictor of survival than magnetic field strength. The presence of a transverse 1.5 T field during irradiation had little to no effect on survival for each of the dose groups. The 1.5 T field did, however, have an effect on the severity of radiation-induced lung injury, as measured by respiratory rate, lung density, and lung volume.
The results of these studies suggest that it is possible to reduce magnetic-field-induced dose perturbations by using parallel-opposed fields, and in this case the impact of a strong, transverse magnetic field on survival would be expected to be insignificant. However, our results also suggest that there could be some impact on the severity of radiation-induced lung damage, though that impact is likely small.
"],"dc:identifier":["https://digitalcommons.library.tmc.edu/utgsbs_dissertations/786"],"dc:subject":["MRIgRT","dose perturbations","mice","radiation-induced pneumonitis","MCNP6","magnetic-field-induced dose effects","MRI-guided radiation therapy","Biophysics","Medical Biophysics","Medicine and Health Sciences","Other Physics"],"dc:title":["A Preclinical Study of Radiation-Induced Lung to xicity When Irradiating In A Strong Magnetic Field"],"thesis:degree_level":["Dissertation (PhD)"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T05:50:02Z"}