Fractionation dose optimization facilities the implementation of transmission proton FLASH-RT.

Autor: Zeng Y; Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China.; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China., Zhang Q; Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China.; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China., Pang B; Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China.; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China., Liu M; Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China.; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China., Chang Y; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China., Wang Y; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China., Quan H; Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China., Yang Z; Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
Jazyk: angličtina
Zdroj: Physics in medicine and biology [Phys Med Biol] 2024 Sep 19; Vol. 69 (19). Date of Electronic Publication: 2024 Sep 19.
DOI: 10.1088/1361-6560/ad75e3
Abstrakt: Objective. The beam switching time and fractional dose influence the FLASH effect. A single-beam-per-fraction (SBPF) scheme using uniform fractional dose (UFD) has been proposed for FLASH- radiotherapy (FLASH-RT) to eliminate the beam switching time. Based on SBPF schemes, a fractionation dose optimization algorithm is proposed to optimize non-UFD plans to maximize the fractionation effect and dose-dependent FLASH effect. Approach. The UFD plan, containing five 236 MeV transmission proton beams, was optimized for 11 patients with peripheral lung cancer, with each beam delivering a uniform dose of 11 Gy to the target. Meanwhile, the non-UFD plan was optimized using fractionation dose optimization. To compare the two plans, the equivalent dose to 2 Gy (EQD2) for the target and normal tissues was calculated with an α / β ratio of 10 and 3, respectively. Both UFD and non-UFD plans ensured that the target received an EQD2 of 96.3 Gy. To investigate the overall improvement in normal tissue sparing with the non-UFD plan, the FLASH-enhanced EQD2 was calculated. Main results. The fractional doses in non-UFD plans ranged between 5.0 Gy and 24.2 Gy. No significant differences were found in EQD2 2% and EQD2 98% of targets between UFD and non-UFD plans. However, the D 95% of the target in non-UFD plans was significantly reduced by 15.1%. The sparing effect in non-UFD plans was significantly improved. The FLASH-enhanced EQD2 mean in normal tissue and ipsilateral lung was significantly reduced by 3.5% and 10.4%, respectively, in non-UFD plans. The overall improvement is attributed to both the FLASH and fractionation effects. Significance. The fractionation dose optimization can address the limitation of multiple-beam FLASH-RT and utilize the relationship between fractional dose and FLASH effect. Consequently, the non-UFD scheme results in further improvements in normal tissue sparing compared to the UFD scheme, attributed to enhanced fractionation and FLASH effects.
(© 2024 Institute of Physics and Engineering in Medicine. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)
Databáze: MEDLINE
Externí odkaz: