Thibault Bernelin, Bryan Muir, James Renaud, Karim Zerouali, Dominique Guillet, Louis Archambault, Arthur Lalonde
{"title":"用于超高剂量率电子束监测和剂量报告的屏蔽束电流互感器的特性。","authors":"Thibault Bernelin, Bryan Muir, James Renaud, Karim Zerouali, Dominique Guillet, Louis Archambault, Arthur Lalonde","doi":"10.1002/mp.17927","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Background</h3>\n \n <p>Real-time beam monitoring and accurate dose reporting is challenging in ultra-high dose rate (UHDR) electron beams. Although beam current transformers (BCTs) can effectively track parameters such as pulse width (PW) and repetition frequency for UHDR electron beams, recent work has highlighted their sensitivity to electric fields induced by transient charge buildup in irradiated media under UHDR conditions.</p>\n </section>\n \n <section>\n \n <h3> Purpose</h3>\n \n <p>This study evaluates the performance of a novel electrostatically shielded BCT for real-time, high-accuracy dose monitoring in UHDR electron beams.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>Irradiations were conducted using the Mobetron linear accelerator configured for UHDR electron beams with energies of 6 and 9 MeV. A shielded BCT was implemented to monitor beam delivery, with dose calibration established using alanine dosimeters in solid water phantoms. Dose stability was assessed over short (7-day) and long (16-week) periods. The BCT's response to variations in PW, pulse number, and pulse repetition frequency was also evaluated to determine its robustness across beam configurations.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>The BCT showed high reproducibility and accuracy, with standard deviations of the difference between BCT-predicted and alanine-measured doses within 0.21% over short-term measurements and 0.57% over long-term measurements, even when subject to large (10%) machine output adjustments. When varying beam parameters, the BCT maintained accurate dose prediction within 1.0% and 1.4% of alanine measurements for 6 and 9 MeV, respectively, with high linearity (<span></span><math>\n <semantics>\n <mrow>\n <msup>\n <mi>R</mi>\n <mn>2</mn>\n </msup>\n <mo>≥</mo>\n </mrow>\n <annotation>${\\rm R}^2\\ge$</annotation>\n </semantics></math> 0.9997) across total doses.</p>\n </section>\n \n <section>\n \n <h3> Conclusion</h3>\n \n <p>Shielded BCTs provide a stable and accurate solution for real-time dose monitoring in FLASH radiotherapy, demonstrating robustness against output fluctuations and beam parameter variations. While further calibration standardization is required, this study supports the feasibility of using shielded BCTs for reliable UHDR dose monitoring, facilitating safe and precise implementation of FLASH radiotherapy in preclinical and clinical settings.</p>\n </section>\n </div>","PeriodicalId":18384,"journal":{"name":"Medical physics","volume":"52 7","pages":""},"PeriodicalIF":3.2000,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mp.17927","citationCount":"0","resultStr":"{\"title\":\"Characterization of a shielded beam current transformer for ultra-high dose rate (FLASH) electron beam monitoring and dose reporting\",\"authors\":\"Thibault Bernelin, Bryan Muir, James Renaud, Karim Zerouali, Dominique Guillet, Louis Archambault, Arthur Lalonde\",\"doi\":\"10.1002/mp.17927\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n \\n <section>\\n \\n <h3> Background</h3>\\n \\n <p>Real-time beam monitoring and accurate dose reporting is challenging in ultra-high dose rate (UHDR) electron beams. Although beam current transformers (BCTs) can effectively track parameters such as pulse width (PW) and repetition frequency for UHDR electron beams, recent work has highlighted their sensitivity to electric fields induced by transient charge buildup in irradiated media under UHDR conditions.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Purpose</h3>\\n \\n <p>This study evaluates the performance of a novel electrostatically shielded BCT for real-time, high-accuracy dose monitoring in UHDR electron beams.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Methods</h3>\\n \\n <p>Irradiations were conducted using the Mobetron linear accelerator configured for UHDR electron beams with energies of 6 and 9 MeV. A shielded BCT was implemented to monitor beam delivery, with dose calibration established using alanine dosimeters in solid water phantoms. Dose stability was assessed over short (7-day) and long (16-week) periods. The BCT's response to variations in PW, pulse number, and pulse repetition frequency was also evaluated to determine its robustness across beam configurations.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Results</h3>\\n \\n <p>The BCT showed high reproducibility and accuracy, with standard deviations of the difference between BCT-predicted and alanine-measured doses within 0.21% over short-term measurements and 0.57% over long-term measurements, even when subject to large (10%) machine output adjustments. When varying beam parameters, the BCT maintained accurate dose prediction within 1.0% and 1.4% of alanine measurements for 6 and 9 MeV, respectively, with high linearity (<span></span><math>\\n <semantics>\\n <mrow>\\n <msup>\\n <mi>R</mi>\\n <mn>2</mn>\\n </msup>\\n <mo>≥</mo>\\n </mrow>\\n <annotation>${\\\\rm R}^2\\\\ge$</annotation>\\n </semantics></math> 0.9997) across total doses.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Conclusion</h3>\\n \\n <p>Shielded BCTs provide a stable and accurate solution for real-time dose monitoring in FLASH radiotherapy, demonstrating robustness against output fluctuations and beam parameter variations. While further calibration standardization is required, this study supports the feasibility of using shielded BCTs for reliable UHDR dose monitoring, facilitating safe and precise implementation of FLASH radiotherapy in preclinical and clinical settings.</p>\\n </section>\\n </div>\",\"PeriodicalId\":18384,\"journal\":{\"name\":\"Medical physics\",\"volume\":\"52 7\",\"pages\":\"\"},\"PeriodicalIF\":3.2000,\"publicationDate\":\"2025-06-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mp.17927\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Medical physics\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/mp.17927\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Medical physics","FirstCategoryId":"3","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/mp.17927","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
Characterization of a shielded beam current transformer for ultra-high dose rate (FLASH) electron beam monitoring and dose reporting
Background
Real-time beam monitoring and accurate dose reporting is challenging in ultra-high dose rate (UHDR) electron beams. Although beam current transformers (BCTs) can effectively track parameters such as pulse width (PW) and repetition frequency for UHDR electron beams, recent work has highlighted their sensitivity to electric fields induced by transient charge buildup in irradiated media under UHDR conditions.
Purpose
This study evaluates the performance of a novel electrostatically shielded BCT for real-time, high-accuracy dose monitoring in UHDR electron beams.
Methods
Irradiations were conducted using the Mobetron linear accelerator configured for UHDR electron beams with energies of 6 and 9 MeV. A shielded BCT was implemented to monitor beam delivery, with dose calibration established using alanine dosimeters in solid water phantoms. Dose stability was assessed over short (7-day) and long (16-week) periods. The BCT's response to variations in PW, pulse number, and pulse repetition frequency was also evaluated to determine its robustness across beam configurations.
Results
The BCT showed high reproducibility and accuracy, with standard deviations of the difference between BCT-predicted and alanine-measured doses within 0.21% over short-term measurements and 0.57% over long-term measurements, even when subject to large (10%) machine output adjustments. When varying beam parameters, the BCT maintained accurate dose prediction within 1.0% and 1.4% of alanine measurements for 6 and 9 MeV, respectively, with high linearity ( 0.9997) across total doses.
Conclusion
Shielded BCTs provide a stable and accurate solution for real-time dose monitoring in FLASH radiotherapy, demonstrating robustness against output fluctuations and beam parameter variations. While further calibration standardization is required, this study supports the feasibility of using shielded BCTs for reliable UHDR dose monitoring, facilitating safe and precise implementation of FLASH radiotherapy in preclinical and clinical settings.
期刊介绍:
Medical Physics publishes original, high impact physics, imaging science, and engineering research that advances patient diagnosis and therapy through contributions in 1) Basic science developments with high potential for clinical translation 2) Clinical applications of cutting edge engineering and physics innovations 3) Broadly applicable and innovative clinical physics developments
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