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Background: Accurate absolute dosimetry is essential for achieving high-precision proton beam therapy. Consequently, a comprehensive characterization of the ionization chamber's response properties is necessary.
Purpose: This study aimed to evaluate the average using Monte Carlo (MC) code PHITS to assess uncertainties among different MC simulation tools. Additionally, values for PTW 30013, NACP-02, and PTW 31013 ionization chambers are calculated using PHITS to provide new reference data for . Furthermore, a new factor for PTW 31013 chamber is established using MC method, contributing to advancements in proton beam dosimetry protocols.
Methods: Monoenergetic proton beams were employed to calculate , , and for Farmer, Semiflex, and plane-parallel chambers. The absorbed dose deposited within the sensitive volume of each chamber was determined via simulations employing PHITS, thereby providing the basis for the estimation of these factors. Computed values were compared with previous reports, while and were benchmarked against literature and Technical Reports Series No. 398 (TRS-398) Rev.1 guideline.
Results: Incorporating PHITS-derived values reduced the uncertainty of compared to previous findings. The factor for PTW 31013 followed trends observed in cylindrical chambers with varying sensitive volumes; notably, this study represents the first MC estimation of for this chamber. values for values deviated by up to 1.7% from unity.
Conclusion: The data generated in this study provide important insights for refining proton beam dosimetry, contributing to the improvement of treatment precision.
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http://dx.doi.org/10.1016/j.tipsro.2025.100325 | DOI Listing |
Indian J Nucl Med
August 2025
Department of Physics, Shi.C., Islamic Azad University, Shiraz, Iran.
Background: Another approach to improve the dose conformity is to use charged particles like protons instead of the conventional X- and γ-rays. Protons exhibit a specific depth-dose distribution which allows to achieve a more targeted dose deposition and a significant sparing of healthy tissue behind the tumor. In particular, proton therapy has, therefore, become a routinely prescribed treatment for tumors located close to sensitive structures.
View Article and Find Full Text PDFPhys Imaging Radiat Oncol
July 2025
Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy.
Biology-guided voxel-level inverse prescription mapping for dose painting (DP) using diffusion-weighted magnetic resonance imaging was evaluated for technical feasibility in proton therapy for 10 skull-base chordoma patients. Patient-specific DP prescriptions were generated from tumour cellularity and implemented in a clinical treatment planning system. Compared with uniform plans, DP achieved lower conformity (although >97 %), improved target dose metrics, reduced doses to most organs at risk, and increased tumour control probability without exceeding clinical constraints.
View Article and Find Full Text PDFMed Phys
September 2025
Department of Radiation Oncology, Mayo Clinic in Florida, Jacksonville, Florida, USA.
Background: Dose-driven continuous scanning (DDCS) enhances the efficiency and precision of proton pencil beam delivery by reducing beam pauses inherent in discrete spot scanning (DSS). However, current DDCS optimization studies using traveling salesman problem (TSP) formulations often rely on fixed beam intensity and computationally expensive interpolation for move spot generation, limiting efficiency and methodological robustness.
Purpose: This study introduces a Break Spot-Guided (BSG) method, combined with two acceleration strategies-dose rate skipping and bounding-to optimize beam intensity while minimizing beam delivery time (BDT).
Med Phys
September 2025
Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
Background: Integrated mode proton imaging is a clinically accessible method for proton radiographs (pRads), but its spatial resolution is limited by multiple Coulomb scattering (MCS). As the amplitude of MCS decreases with increasing particle charge, heavier ions such as carbon ions produce radiographs with better resolution (cRads). Improving image resolution of pRads may thus be achieved by transferring individual proton pencil beam images to the equivalent carbon ion data using a trained image translation network.
View Article and Find Full Text PDFOral Dis
September 2025
Clinical Department, Radiation Oncology Unit, National Center for Oncological Hadrontherapy (CNAO), Pavia, Italy.
Aim: To evaluate the outcomes of combining carbon ion radiotherapy boost (CIRTb) with photons (Ph) or protons (PT) for locally advanced salivary gland and sinonasal cancers (SGCs and SNCs).
Materials And Methods: Sixty-nine patients with SGCs and SNCs received CIRTb to high-risk CTV and Ph or PT to low-risk CTV (LR-CTV) from October 2014 to September 2022. Two-year local relapse-free survival (LRFS) was analyzed with Kaplan-Meier.