Characterizing diamond detectors for various dose and dose rate measurements in scanned carbon and oxygen beams

IF 3.2 2区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Medical physics Pub Date : 2025-06-02 DOI:10.1002/mp.17893

Celine Karle, Gianluca Verona-Rinati, Stephan Brons, Rainer Cee, Stefan Scheloske, Christian Schömers, Rafael Kranzer, Thomas Haberer, Marco Marinelli, Andrea Mairani, Thomas Tessonnier

{"title":"Characterizing diamond detectors for various dose and dose rate measurements in scanned carbon and oxygen beams","authors":"Celine Karle, Gianluca Verona-Rinati, Stephan Brons, Rainer Cee, Stefan Scheloske, Christian Schömers, Rafael Kranzer, Thomas Haberer, Marco Marinelli, Andrea Mairani, Thomas Tessonnier","doi":"10.1002/mp.17893","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Background</h3>\n \n <p>The emerging FLASH radiotherapy technique employs “Ultra-High Dose Rate” (UHDR) irradiations and offers the potential to spare normal tissue while maintaining iso-effective tumor treatment. Given the physical and biological advantages inherent to high “Linear Energy Transfer” (LET) particles, the combination of UHDR and high LET has the capability to enhance the normal tissues sparing, as indicated by initial in vivo trials. However, to ensure a safe implementation of this combined modality, it is essential to establish robust dosimetric protocols utilizing dose-, dose rate-, and LET-independent detectors.</p>\n </section>\n \n <section>\n \n <h3> Purpose</h3>\n \n <p>The objective of this study is to characterize the dose, dose rate, and LET dependency of two diamond detectors with high LET carbon and oxygen ion irradiation under “Standard Dose Rate” (SDR) and UHDR conditions.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>The “microDiamond” (mD) and a “flashDiamond” (fD) prototype were benchmarked against measurements with a monitoring ionization chamber, Advanced Markus chamber (AMC), and simulations for carbon and oxygen irradiation, with energies of 274.98 MeV/u and 325.98 MeV/u under SDR and UHDR conditions. First, the entire depth-dose profiles obtained during SDR irradiations and the partial in-depth profiles of the Bragg peak region in UHDR were compared to the corresponding simulation values. Secondly, the linearity of the diamond detector response during dose escalation measurements was investigated for both dose rates.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>The two detectors exhibited alignment with the simulated depth-dose distributions for oxygen and carbon irradiations across both dose rate conditions. The mD overestimated the dose values for carbon and oxygen measurements. This overestimation increased with “dose-averaged LET” (LETd) during SDR irradiation and maintained a stable value of 5% for UHDR. Meanwhile, the fD demonstrated a high degree of agreement with the simulation, with a maximum discrepancy of 5% across all irradiation modalities in the plateau and “Bragg Peak” (BP). Deviations were observed in the BP fall-off region, while both diamond detectors exhibited a strong alignment with the AMC measurements. Furthermore, both detectors exhibited dose linearity under SDR and UHDR irradiation for both carbon and oxygen irradiation, with a coefficient of determination (<i>R</i><sup>2</sup>) above 0.99.</p>\n </section>\n \n <section>\n \n <h3> Conclusion</h3>\n \n <p>In the context of heavy ion carbon and oxygen irradiation in UHDR and SDR, the two diamond detectors demonstrated dose-rate independence. While the mD exhibited a tendency to overestimate dose values with increasing LETd, the fD was found to be LET-independent. The fD appears to offer accurate and reliable dose assessments for UHDR heavy ion experiments.</p>\n </section>\n </div>","PeriodicalId":18384,"journal":{"name":"Medical physics","volume":"52 7","pages":""},"PeriodicalIF":3.2000,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mp.17893","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Medical physics","FirstCategoryId":"3","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/mp.17893","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}

引用次数: 0

Abstract

Background

The emerging FLASH radiotherapy technique employs “Ultra-High Dose Rate” (UHDR) irradiations and offers the potential to spare normal tissue while maintaining iso-effective tumor treatment. Given the physical and biological advantages inherent to high “Linear Energy Transfer” (LET) particles, the combination of UHDR and high LET has the capability to enhance the normal tissues sparing, as indicated by initial in vivo trials. However, to ensure a safe implementation of this combined modality, it is essential to establish robust dosimetric protocols utilizing dose-, dose rate-, and LET-independent detectors.

Purpose

The objective of this study is to characterize the dose, dose rate, and LET dependency of two diamond detectors with high LET carbon and oxygen ion irradiation under “Standard Dose Rate” (SDR) and UHDR conditions.

Methods

The “microDiamond” (mD) and a “flashDiamond” (fD) prototype were benchmarked against measurements with a monitoring ionization chamber, Advanced Markus chamber (AMC), and simulations for carbon and oxygen irradiation, with energies of 274.98 MeV/u and 325.98 MeV/u under SDR and UHDR conditions. First, the entire depth-dose profiles obtained during SDR irradiations and the partial in-depth profiles of the Bragg peak region in UHDR were compared to the corresponding simulation values. Secondly, the linearity of the diamond detector response during dose escalation measurements was investigated for both dose rates.

Results

The two detectors exhibited alignment with the simulated depth-dose distributions for oxygen and carbon irradiations across both dose rate conditions. The mD overestimated the dose values for carbon and oxygen measurements. This overestimation increased with “dose-averaged LET” (LETd) during SDR irradiation and maintained a stable value of 5% for UHDR. Meanwhile, the fD demonstrated a high degree of agreement with the simulation, with a maximum discrepancy of 5% across all irradiation modalities in the plateau and “Bragg Peak” (BP). Deviations were observed in the BP fall-off region, while both diamond detectors exhibited a strong alignment with the AMC measurements. Furthermore, both detectors exhibited dose linearity under SDR and UHDR irradiation for both carbon and oxygen irradiation, with a coefficient of determination (R²) above 0.99.

Conclusion

In the context of heavy ion carbon and oxygen irradiation in UHDR and SDR, the two diamond detectors demonstrated dose-rate independence. While the mD exhibited a tendency to overestimate dose values with increasing LETd, the fD was found to be LET-independent. The fD appears to offer accurate and reliable dose assessments for UHDR heavy ion experiments.

Abstract Image

查看原文本刊更多论文

在扫描的碳和氧光束中测量不同剂量和剂量率的金刚石探测器的特性。

背景：新兴的FLASH放射治疗技术采用“超高剂量率”（UHDR）照射，在保持肿瘤治疗等效的同时，提供了保留正常组织的潜力。鉴于高“线性能量传递”（LET）粒子所固有的物理和生物优势，正如最初的体内试验所表明的那样，UHDR和高LET的结合具有增强正常组织保留的能力。然而，为了确保这种组合方式的安全实施，必须建立可靠的剂量学方案，利用剂量、剂量率和let无关的探测器。目的：本研究的目的是表征两种高LET碳氧离子辐照的金刚石探测器在“标准剂量率”（SDR）和UHDR条件下的剂量、剂量率和LET依赖性。方法：采用监测电离室、先进Markus室（AMC）和碳、氧辐照模拟，对“microDiamond”（mD）和“flashDiamond”（fD）原型进行了基准测试，在SDR和UHDR条件下的能量分别为274.98 MeV/u和325.98 MeV/u。首先，将SDR辐照获得的整个深度-剂量谱和UHDR中布拉格峰区域的部分深度谱与相应的模拟值进行比较。其次，研究了两种剂量率下金刚石探测器在剂量递增测量过程中的线性响应。结果：在两种剂量率条件下，两个探测器与模拟的氧和碳辐照深度剂量分布一致。mD高估了碳和氧测量的剂量值。在SDR照射期间，这种高估随着“剂量平均LET”（LETd）的增加而增加，并在UHDR中保持5%的稳定值。同时，fD显示了与模拟的高度一致，在高原和“布拉格峰”（BP）的所有照射模式中，最大差异为5%。在BP衰减区观察到偏差，而两个金刚石探测器都显示出与AMC测量结果强烈的一致性。此外，两种探测器在SDR和UHDR辐照下，碳和氧辐照均表现出剂量线性，决定系数（R2）均在0.99以上。结论：在UHDR和SDR的重离子碳氧照射下，两种金刚石探测器表现出剂量率无关性。虽然mD显示出高估剂量值的趋势，但发现fD与let无关。fD似乎为UHDR重离子实验提供了准确可靠的剂量评估。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Medical physics 医学-核医学

CiteScore

6.80

自引率

15.80%

发文量

660

审稿时长

1.7 months

期刊介绍： Medical Physics publishes original, high impact physics, imaging science, and engineering research that advances patient diagnosis and therapy through contributions in 1) Basic science developments with high potential for clinical translation 2) Clinical applications of cutting edge engineering and physics innovations 3) Broadly applicable and innovative clinical physics developments Medical Physics is a journal of global scope and reach. By publishing in Medical Physics your research will reach an international, multidisciplinary audience including practicing medical physicists as well as physics- and engineering based translational scientists. We work closely with authors of promising articles to improve their quality.