Lingshu Yin, Daniel Sforza, Devin Miles, Umezawa Masumi, Kan Ota, Xun Jia, Heng Li
{"title":"同步加速器质子治疗系统中142.4 MeV超高剂量率（UHDR）质子束线的调试","authors":"Lingshu Yin, Daniel Sforza, Devin Miles, Umezawa Masumi, Kan Ota, Xun Jia, Heng Li","doi":"10.1002/mp.18008","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Background</h3>\n \n <p>Recent studies suggest that radiotherapy at ultrahigh dose rates (>40 Gy/s, FLASH) offers normal tissue sparing effects while maintaining tumor control. There is significant interest in preclinical studies investigating the mechanism of FLASH sparing effects.</p>\n </section>\n \n <section>\n \n <h3> Purpose</h3>\n \n <p>This study aims to commission a fixed proton beamline within a synchrotron-based proton therapy system for preclinical proton FLASH research.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>Modifications were made to the Hitachi PROBEAT-CR synchrotron system to enhance RF extraction power and increase proton beam current at 142.4 MeV. A high-speed electrometer and an optimized transmission ion chamber (IC) were implemented for ultra-high dose rate (UHDR) beam monitoring and delivery, replacing the conventional beam monitoring IC. Beam output was measured using a Faraday cup in both UHDR and clinical modes. Gafchromic film measurements and Monte Carlo simulations were employed to validate dose delivery in a solid water phantom with various spot scanning patterns.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>The calibration of transmission IC against Faraday cup shows sufficient charge collection efficiency at both clinical dose rates and UHDR. The UHDR PBS beamline demonstrates better than 1% reproducibility and linearity in the absolute beam output. Due to the limited charge per spill, the delivered dose per spill is inversely proportional to the field size. However, the system can deliver up to 41.4 Gy (268.1 Gy/sec) at 2 cm depth with a field size (FWHM) of 8.2 mm, demonstrating suitability for small animal proton FLASH irradiation studies.</p>\n </section>\n \n <section>\n \n <h3> Conclusion</h3>\n \n <p>We successfully commissioned a fixed beam proton UHDR PBS beamline in a synchrotron-based proton therapy system. Despite synchrotron-specific system constraints, our system enables controlled UHDR delivery for preclinical proton FLASH research.</p>\n </section>\n </div>","PeriodicalId":18384,"journal":{"name":"Medical physics","volume":"52 7","pages":""},"PeriodicalIF":3.2000,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mp.18008","citationCount":"0","resultStr":"{\"title\":\"Commissioning of a 142.4 MeV ultra-high dose rate (UHDR) proton beamline in a synchrotron-based proton therapy system\",\"authors\":\"Lingshu Yin, Daniel Sforza, Devin Miles, Umezawa Masumi, Kan Ota, Xun Jia, Heng Li\",\"doi\":\"10.1002/mp.18008\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div>\\n \\n \\n <section>\\n \\n <h3> Background</h3>\\n \\n <p>Recent studies suggest that radiotherapy at ultrahigh dose rates (>40 Gy/s, FLASH) offers normal tissue sparing effects while maintaining tumor control. There is significant interest in preclinical studies investigating the mechanism of FLASH sparing effects.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Purpose</h3>\\n \\n <p>This study aims to commission a fixed proton beamline within a synchrotron-based proton therapy system for preclinical proton FLASH research.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Methods</h3>\\n \\n <p>Modifications were made to the Hitachi PROBEAT-CR synchrotron system to enhance RF extraction power and increase proton beam current at 142.4 MeV. A high-speed electrometer and an optimized transmission ion chamber (IC) were implemented for ultra-high dose rate (UHDR) beam monitoring and delivery, replacing the conventional beam monitoring IC. Beam output was measured using a Faraday cup in both UHDR and clinical modes. Gafchromic film measurements and Monte Carlo simulations were employed to validate dose delivery in a solid water phantom with various spot scanning patterns.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Results</h3>\\n \\n <p>The calibration of transmission IC against Faraday cup shows sufficient charge collection efficiency at both clinical dose rates and UHDR. The UHDR PBS beamline demonstrates better than 1% reproducibility and linearity in the absolute beam output. Due to the limited charge per spill, the delivered dose per spill is inversely proportional to the field size. However, the system can deliver up to 41.4 Gy (268.1 Gy/sec) at 2 cm depth with a field size (FWHM) of 8.2 mm, demonstrating suitability for small animal proton FLASH irradiation studies.</p>\\n </section>\\n \\n <section>\\n \\n <h3> Conclusion</h3>\\n \\n <p>We successfully commissioned a fixed beam proton UHDR PBS beamline in a synchrotron-based proton therapy system. 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Commissioning of a 142.4 MeV ultra-high dose rate (UHDR) proton beamline in a synchrotron-based proton therapy system
Background
Recent studies suggest that radiotherapy at ultrahigh dose rates (>40 Gy/s, FLASH) offers normal tissue sparing effects while maintaining tumor control. There is significant interest in preclinical studies investigating the mechanism of FLASH sparing effects.
Purpose
This study aims to commission a fixed proton beamline within a synchrotron-based proton therapy system for preclinical proton FLASH research.
Methods
Modifications were made to the Hitachi PROBEAT-CR synchrotron system to enhance RF extraction power and increase proton beam current at 142.4 MeV. A high-speed electrometer and an optimized transmission ion chamber (IC) were implemented for ultra-high dose rate (UHDR) beam monitoring and delivery, replacing the conventional beam monitoring IC. Beam output was measured using a Faraday cup in both UHDR and clinical modes. Gafchromic film measurements and Monte Carlo simulations were employed to validate dose delivery in a solid water phantom with various spot scanning patterns.
Results
The calibration of transmission IC against Faraday cup shows sufficient charge collection efficiency at both clinical dose rates and UHDR. The UHDR PBS beamline demonstrates better than 1% reproducibility and linearity in the absolute beam output. Due to the limited charge per spill, the delivered dose per spill is inversely proportional to the field size. However, the system can deliver up to 41.4 Gy (268.1 Gy/sec) at 2 cm depth with a field size (FWHM) of 8.2 mm, demonstrating suitability for small animal proton FLASH irradiation studies.
Conclusion
We successfully commissioned a fixed beam proton UHDR PBS beamline in a synchrotron-based proton therapy system. Despite synchrotron-specific system constraints, our system enables controlled UHDR delivery for preclinical proton FLASH research.
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
Medical Physics is a journal of global scope and reach. By publishing in Medical Physics your research will reach an international, multidisciplinary audience including practicing medical physicists as well as physics- and engineering based translational scientists. We work closely with authors of promising articles to improve their quality.
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