Monte Carlo investigation of Ge-doped silica fiber detectors for precision small field dosimetry

IF 1.8 3区物理与天体物理 Q2 NUCLEAR SCIENCE & TECHNOLOGY

Radiation Measurements Pub Date : 2026-01-01 Epub Date: 2025-10-31 DOI:10.1016/j.radmeas.2025.107552

A. Khodaei , F. Moradi , H.T. Zubair , S.A. Ibrahim , H.A. Abdul-Rashid

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引用次数: 0

Abstract

Accurate dosimetry in small radiation fields remains a critical challenge in modern radiotherapy due to high dose gradients and limited detector spatial resolution. This study investigates the dosimetric performance of Ge-doped silica fiber radioluminescence (RL) detectors for small field measurements through Monte Carlo simulations using the TOPAS tool. Reference data from IAEA database were utilized for implementation of small radiation fields and validation, by comparing experimental beam profile and depth dose measurements for various field sizes. Quality dependence factors (QDFs) were calculated based on the formalism of the IAEA-AAPM working group, considering a Varian Clinac iX linear accelerator with a 10 × 10 cm² reference field and various small fields of 0.5 × 0.5 cm², 1 × 1 cm², 2 × 2 cm² and 4 × 4 cm². The study explored different fiber detector diameters from 125 μm to 2 mm to optimize spatial resolution for small field dosimetry. Simulated electron spectra in various situations were analyzed in both water and fiber volumes to understand reasons behind detector response variations. Notably, the detector diameter significantly influenced quality dependence, with competing effects between energy dependence and a field size dependent spectral discrepancy leading to an optimal balance at a 0.5 mm fiber diameter. Calculated QDFs aligned well within the range reported for other detector types, supporting the applicability of Ge-doped silica fiber RL detectors for precise dose measurements in small radiation fields, offering a potential alternative for advanced radiotherapy applications.

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用于精密小场剂量测定的掺锗二氧化硅光纤探测器的蒙特卡罗研究

由于高剂量梯度和探测器空间分辨率有限，小辐射场的精确剂量测量仍然是现代放射治疗的一个关键挑战。本研究利用TOPAS工具通过蒙特卡罗模拟研究了掺锗硅纤维辐射发光（RL）探测器在小场测量中的剂量学性能。利用国际原子能机构数据库的参考数据实施小辐射场并进行验证，通过比较不同场大小的实验光束剖面和深度剂量测量。考虑瓦里安Clinac iX直线加速器的参考场为10 × 10 cm2，小场为0.5 × 0.5 cm2、1 × 1 cm2、2 × 2 cm2和4 × 4 cm2，根据IAEA-AAPM工作组的公式计算了质量依赖因子（qdf）。为了优化小场剂量测量的空间分辨率，研究了直径为125 μm至2 mm的不同光纤探测器。分析了不同情况下水和纤维体积下的模拟电子能谱，以了解探测器响应变化背后的原因。值得注意的是，探测器直径显著影响了质量依赖性，在能量依赖性和场尺寸依赖性光谱差异之间存在竞争效应，导致在0.5 mm光纤直径处达到最佳平衡。计算出的qdf在其他探测器类型的报告范围内排列良好，支持掺锗硅光纤RL探测器在小辐射场中进行精确剂量测量的适用性，为高级放射治疗应用提供了潜在的替代方案。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Radiation Measurements 工程技术-核科学技术

CiteScore

4.10

自引率

20.00%

发文量

116

审稿时长

48 days

期刊介绍： The journal seeks to publish papers that present advances in the following areas: spontaneous and stimulated luminescence (including scintillating materials, thermoluminescence, and optically stimulated luminescence); electron spin resonance of natural and synthetic materials; the physics, design and performance of radiation measurements (including computational modelling such as electronic transport simulations); the novel basic aspects of radiation measurement in medical physics. Studies of energy-transfer phenomena, track physics and microdosimetry are also of interest to the journal. Applications relevant to the journal, particularly where they present novel detection techniques, novel analytical approaches or novel materials, include: personal dosimetry (including dosimetric quantities, active/electronic and passive monitoring techniques for photon, neutron and charged-particle exposures); environmental dosimetry (including methodological advances and predictive models related to radon, but generally excluding local survey results of radon where the main aim is to establish the radiation risk to populations); cosmic and high-energy radiation measurements (including dosimetry, space radiation effects, and single event upsets); dosimetry-based archaeological and Quaternary dating; dosimetry-based approaches to thermochronometry; accident and retrospective dosimetry (including activation detectors), and dosimetry and measurements related to medical applications.