用EBT3放射变色薄膜和蒙特卡罗模拟对六种Ru-106眼膜进行剂量学研究。

Dosimetric Investigation of Six Ru-106 Eye Plaques by EBT3 Radiochromic Films and Monte Carlo Simulation.

作者信息

Arjmand Mojtaba, Ghassemi Fariba, Rafiepour Payman, Zeinali Reyhaneh, Riazi-Esfahani Hamid, Beiki-Ardakani Akbar

机构信息

Ocular Oncology service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

Retina & Vitreous Service- Ocular Oncology Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

出版信息

J Biomed Phys Eng. 2023 Aug 1;13(4):309-316. doi: 10.31661/jbpe.v0i0.2010-1206. eCollection 2023 Aug.

DOI:10.31661/jbpe.v0i0.2010-1206

PMID:37609514

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10440413/

Abstract

BACKGROUND

Ophthalmic brachytherapy using radioactive plaques is an effective technique for the treatment of uveal melanoma. Ru-106 eye plaques are considered as interesting issue due to their steep gradient dose. The pre-planning evaluation of dosimetric parameters is essential for the treatment planning system.

OBJECTIVE

The current study aims at providing dose distributions of six Ru-106 eye plaques (CCA, CCB, CGD, CIB, COB and COD) using radiochromic EBT3 film, Geant4 Monte Carlo toolkit and the treatment planning software (Plaque Simulator).

MATERIAL AND METHODS

In this experimental study, an in-house phantom was employed for depth dose measurements with EBT3 films. Also, Geant4.10.5 scoring mesh was implemented to obtain the 2D dose distribution of the plaques. The results were compared with Plaque Simulator software and the manufacturer's (BEBIG) data. The gamma index criterion (3%/3 mm) was used to evaluate dose distributions obtained by the film measurements and Geant4 simulation.

RESULTS

A good agreement was achieved between simulation and experimental results. Gamma index passing rate was 94.2%, 89.3%, 88.2%, 82.2%, 92.2% and 90.1% for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Absolute dose rate (mGy/min) obtained by EBT3 film at the depth of 2 mm was 79.4 mGy/min, 81.0 mGy/min, 78.6 mGy/min, 62.2 mGy/min, 75.2 mGy/min and 81.2 mGy/min for CCA, CCB, CGD, CIB, COB and COD plaques, respectively.

CONCLUSION

The measured dose distributions and lateral dose profiles may be utilized in the treatment planning system to cover clinical volumes such as the clinical target volume and the gross tumor volume.

摘要

背景

使用放射性敷贴器的眼科近距离放射治疗是治疗葡萄膜黑色素瘤的有效技术。由于其陡峭的剂量梯度，Ru-106眼用敷贴器被视为一个有趣的研究对象。剂量学参数的预规划评估对于治疗计划系统至关重要。

目的

本研究旨在使用放射变色EBT3胶片、Geant4蒙特卡罗工具包和治疗计划软件（敷贴器模拟器）提供六种Ru-106眼用敷贴器（CCA、CCB、CGD、CIB、COB和COD）的剂量分布。

材料与方法

在本实验研究中，使用自制体模结合EBT3胶片进行深度剂量测量。此外，实施Geant4.10.5评分网格以获得敷贴器的二维剂量分布。将结果与敷贴器模拟器软件和制造商（BEBIG）的数据进行比较。使用伽马指数标准（3%/3 mm）评估通过胶片测量和Geant4模拟获得的剂量分布。

结果

模拟结果与实验结果达成了良好的一致性。CCA、CCB、CGD、CIB、COB和COD敷贴器的伽马指数通过率分别为94.2%、89.3%、88.2%、82.2%、92.2%和90.1%。EBT3胶片在2 mm深度处获得的绝对剂量率（mGy/min），CCA、CCB、CGD、CIB、COB和COD敷贴器分别为79.4 mGy/min、81.0 mGy/min、78.6 mGy/min、62.2 mGy/min、75.2 mGy/min和81.2 mGy/min。