by Yuwei Zhu, Carla Riera-Llobet, Celeste Fleta, María Manna, Amélia Maia Leite, Gastón García López, Vicente García Távora, Diana Bachiller-Perea, Quentin Mouchard and Consuelo Guardiola
Abstract:
The experimental assessment of the linear energy transfer (LET) at micrometric scale with high resolution is mandatory to achieve biologically optimized treatment plans in hadron therapy. Therefore, it is crucial to create active radiation sensors able to quantify microdosimetry distributions in three-dimensions under clinical conditions. We have quantified the first microdosimetry 2D-maps delivered by alpha beams with the highest resolution so far (400 μm × 600 μm) using a customized sensor. It consists of 3 multi-arrays of 50 3 × 3 microdetectors with a pitch of 200 μm that cover a total radiation sensitive area of 9 cm × 0.4 mm. The microdetectors are based on a novel 3D-cylindrical silicon architecture with 25-μm diameter and 20-μm thickness. The back-side of these sensors is etched to avoid back-scattering contributions in heavy ion fields. This system was calibrated with alpha beams from 5.75 to 20 MeV in the Accelerateur Lineaire et Tandem a Orsay (ALTO), France, and irradiated with pulsed beams (from 1.4 μs to 3.3 μs pulse widths) of 7.5 MeV alphas in the Centro de Micro-Analisis de Materiales (CMAM), Spain. We worked with clinical equivalent fluence rates in both continuous irradiation mode ( 10 cm-2s-1) and in pulsed regimes with higher fluence rates up to 1010 cm-2-s-1. Measurements of pulse height spectra were collected with the sensor in both modes. The experimental results were crosschecked with Monte Carlo simulations using the GATE code. The simulated spectral shapes and peak positions showed good agreement with the experimental data, with relative differences of less than 3.5% for all the energies studied. Results show that the new microdosimetry array, specially manufactured for ions, is a reliable tool for LET characterization of ions in both continuous and pulsed modes.
Reference:
Yuwei Zhu, Carla Riera-Llobet, Celeste Fleta, María Manna, Amélia Maia Leite, Gastón García López, Vicente García Távora, Diana Bachiller-Perea, Quentin Mouchard and Consuelo Guardiola, “Microdosimetry Maps in Continuous and Pulsed Alpha Beams”, IEEE Transactions on Radiation and Plasma Medical Sciences, pp. 1–1.
Bibtex Entry:
@article{zhu_microdosimetry_2025,
title = {Microdosimetry {Maps} in {Continuous} and {Pulsed} {Alpha} {Beams}},
issn = {2469-7303},
url = {https://ieeexplore.ieee.org/abstract/document/11203787},
doi = {10.1109/TRPMS.2025.3620266},
abstract = {The experimental assessment of the linear energy transfer (LET) at micrometric scale with high resolution is mandatory to achieve biologically optimized treatment plans in hadron therapy. Therefore, it is crucial to create active radiation sensors able to quantify microdosimetry distributions in three-dimensions under clinical conditions. We have quantified the first microdosimetry 2D-maps delivered by alpha beams with the highest resolution so far (400 μm × 600 μm) using a customized sensor. It consists of 3 multi-arrays of 50 3 × 3 microdetectors with a pitch of 200 μm that cover a total radiation sensitive area of 9 cm × 0.4 mm. The microdetectors are based on a novel 3D-cylindrical silicon architecture with 25-μm diameter and 20-μm thickness. The back-side of these sensors is etched to avoid back-scattering contributions in heavy ion fields. This system was calibrated with alpha beams from 5.75 to 20 MeV in the Accelerateur Lineaire et Tandem a Orsay (ALTO), France, and irradiated with pulsed beams (from 1.4 μs to 3.3 μs pulse widths) of 7.5 MeV alphas in the Centro de Micro-Analisis de Materiales (CMAM), Spain. We worked with clinical equivalent fluence rates in both continuous irradiation mode ( 10 cm-2s-1) and in pulsed regimes with higher fluence rates up to 1010 cm-2-s-1. Measurements of pulse height spectra were collected with the sensor in both modes. The experimental results were crosschecked with Monte Carlo simulations using the GATE code. The simulated spectral shapes and peak positions showed good agreement with the experimental data, with relative differences of less than 3.5% for all the energies studied. Results show that the new microdosimetry array, specially manufactured for ions, is a reliable tool for LET characterization of ions in both continuous and pulsed modes.},
urldate = {2025-11-25},
journal = {IEEE Transactions on Radiation and Plasma Medical Sciences},
author = {Zhu, Yuwei and Riera-Llobet, Carla and Fleta, Celeste and Manna, María and Leite, Amélia Maia and López, Gastón García and Távora, Vicente García and Bachiller-Perea, Diana and Mouchard, Quentin and Guardiola, Consuelo},
year = {2025},
keywords = {Radiation effects, Silicon, Protons, alpha therapy, Electronic mail, Etching, Field programmable gate arrays, hadron therapy, Ions, Medical treatment, microdosimetry, particle detectors, Sensors, silicon microdosimeters, Tumors},
pages = {1--1},
file = {Full Text PDF:E:\Usuarios\Administrator\Zotero\storage\XV8TCHQE\Zhu et al. - 2025 - Microdosimetry Maps in Continuous and Pulsed Alpha Beams.pdf:application/pdf},
}