Up modulation of dose-averaged linear energy transfer by simultaneous integrated boost in carbon-ion radiotherapy for pancreatic carcinoma.

Autor: Wang W; Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China.; Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai, China., Sun J; Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China., Zhao J; Department of Medical Physics, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China.; Department of Radiation Oncology, Fudan University Cancer Center, Shanghai, China., Cheng J; Department of Nuclear Medicine, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China., Jiang GL; Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China., Wang Z; Department of Radiation Oncology, Shanghai Proton and Heavy Ion Center, Fudan University Cancer Hospital, Shanghai Key Laboratory of Radiation Oncology (20dz2261000), Shanghai Engineering Research Center of Proton and Heavy Ion Radiation Therapy, Shanghai, China.
Jazyk: angličtina
Zdroj: Journal of applied clinical medical physics [J Appl Clin Med Phys] 2024 Jun; Vol. 25 (6), pp. e14279. Date of Electronic Publication: 2024 Jan 23.
DOI: 10.1002/acm2.14279
Abstrakt: Background: Local recurrence in locally advanced pancreatic cancer (LAPC) after carbon-ion radiotherapy (CIRT) may partly attribute to low dose-averaged linear energy transfer (LET d ), despite high CIRT dose.
Purpose: This study aimed to investigate the approaches to up-modulate the CIRT LET d and to evaluate the corresponding oxygen enhancement ratio (OER) reduction.
Methods: 10 LAPCs that had been irradiated by CIRT with 67.5 Gy (RBE) in 15 fractions were selected. Their original plans were taken as the control plan for the LET d and OER investigations. Our considerations for up-modulating LET d were: (1) to deliver high doses to gross tumor volume core (GTVcore), while keeping dose constraints of the gastrointestinal (GI) tract in tolerance; (2) to put more Bragg-peak (BP) within the modulated targets; (3) to increase the BP density, high doses were necessary; (4) CIRT LET d could be effectively increased to small volumes; and (5) simultaneous integrated boost technique (SIB) could achieve the aforementioned tasks. The LET d and the corresponding OER distributions of each type of SIB plan were evaluated.
Results: We delivered up to 100 Gy (RBE) to GTVcore using SIB. The mean LET d of GTV increased significantly by 21.3% from 47.8 to 58.0 keV/μm (p < 0.05). Meanwhile, the mean OER of GTVcore decreased by 6.6%, from 1.51 to 1.41 (p < 0.05). The GI LET d S in all modulated plans were not more than those in the original plans.
Conclusions: SIB could effectively increase CIRT LET d to LAPC, thus producing reduced OER, which may effectively overcome the radioresistance of LAPCs.
(© 2024 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)
Databáze: MEDLINE
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