Up modulation of dose-averaged linear energy transfer by simultaneous integrated boost in carbon-ion radiotherapy for pancreatic carcinoma.
J Appl Clin Med Phys
; 25(6): e14279, 2024 Jun.
Article
em En
| MEDLINE
| ID: mdl-38259194
ABSTRACT
BACKGROUND:
Local recurrence in locally advanced pancreatic cancer (LAPC) after carbon-ion radiotherapy (CIRT) may partly attribute to low dose-averaged linear energy transfer (LETd), despite high CIRT dose.PURPOSE:
This study aimed to investigate the approaches to up-modulate the CIRT LETd 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 LETd and OER investigations. Our considerations for up-modulating LETd 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 LETd could be effectively increased to small volumes; and (5) simultaneous integrated boost technique (SIB) could achieve the aforementioned tasks. The LETd 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 LETd 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 LETdS in all modulated plans were not more than those in the original plans.CONCLUSIONS:
SIB could effectively increase CIRT LETd to LAPC, thus producing reduced OER, which may effectively overcome the radioresistance of LAPCs.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Pancreáticas
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Dosagem Radioterapêutica
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Planejamento da Radioterapia Assistida por Computador
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Transferência Linear de Energia
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Radioterapia de Intensidade Modulada
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Radioterapia com Íons Pesados
Limite:
Humans
Idioma:
En
Revista:
J Appl Clin Med Phys
Assunto da revista:
BIOFISICA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China