LET
d Optimization Verification With an SOI Microdosimeter.
Int J Radiat Oncol Biol Phys 2024:S0360-3016(23)08310-4. [PMID:
38300188 DOI:
10.1016/j.ijrobp.2023.12.036]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 11/30/2023] [Accepted: 12/23/2023] [Indexed: 02/02/2024]
Abstract
PURPOSE
A first of its kind experimental verification of dose-averaged linear energy transfer (LETd) optimized treatment plans for proton therapy has been carried out using a silicon-on-insulator microdosimeter at the Massachusetts General Hospital (MGH), Boston, USA.
METHODS AND MATERIALS
Three clinical treatment plans of a typical ependymoma structure set were designed using the standard clinical approach, the proposed protocol approach, and a one-field approach. The plans were then reoptimized to reduce the LETd-weighted dose in the brain stem. All six plans were delivered in a solid water phantom and the experimental yD‾ measured.
RESULTS
After LETd optimization, a reduction in yD‾ was found within the brain stem by an average of 12%, 19%, and 4% for the clinical, protocol, and one-field plans, respectively, while maintaining adequate coverage of the tumor structure. The experimental LETd-weighted doses were in agreement with the treatment planning system calculations and Monte Carlo simulations and reinforced the improvement of the optimization.
CONCLUSIONS
This work demonstrates the first experimental verification of the clinical implementation of LETd optimization for patient treatment with proton therapy.
Collapse