{"title":"In vitro and in silico study of biological effects on cancer cells in the presence of metallic materials during radiotherapy.","authors":"Takuya Nagano, Yusuke Matsuya, Atsushi Kaida, Hitomi Nojima, Takuya Furuta, Kaoru Sato, Ryoichi Yoshimura, Masahiko Miura","doi":"10.1093/jrr/rrae062","DOIUrl":null,"url":null,"abstract":"<p><p>X-ray therapy aims to eliminate tumours while minimizing side effects. Intense mucositis is sometimes induced when irradiating the oral cavity with a dental metal crown (DMC). However, the underlying mechanisms of such inducing radiosensitization by DMC remain uncertain. This study explored the radiosensitizing mechanisms around DMCs in an interdisciplinary approach with cell experiments and Monte Carlo simulation with the PHITS code. Clonogenic survival and nuclear 53BP1 foci of a cell line derived from cervical cancer cells (HeLa cells) were measured post-irradiation with therapeutic X-rays near high-Z materials such as Pb or Au plates, and the experimental sensitizer enhancement ratio (SER) was obtained. Meanwhile, the dose enhancement ratio (DER) and relative biological effectiveness for DNA damage yields were calculated using the PHITS code, by considering the corresponding experimental condition. The experiments show the experimental SER values for cell survival and 53BP1 foci near metals are 1.2-1.4, which agrees well with the calculated DER values. These suggest that the radiosensitizing effects near metal are predominantly attributed to the dose increase. In addition, as a preclinical evaluation, the spatial distributions of DER near DMC are calculated using Computed Tomography Digital Imaging and Communications in Medicine (CT-DICOM) data and a simple tooth model. As a result, the DER values evaluated using the CT-DICOM data were lower than those from a simple tooth model. These findings highlight the challenge of evaluating radiosensitizing effects near DMCs using Digital Imaging and Communications in Medicine (DICOM) images due to volume-averaging effects and emphasize the need for a high-resolution (<1 mm) dose assessment method unaffected by these effects.</p>","PeriodicalId":16922,"journal":{"name":"Journal of Radiation Research","volume":" ","pages":"628-639"},"PeriodicalIF":1.9000,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11420842/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Radiation Research","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1093/jrr/rrae062","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
X-ray therapy aims to eliminate tumours while minimizing side effects. Intense mucositis is sometimes induced when irradiating the oral cavity with a dental metal crown (DMC). However, the underlying mechanisms of such inducing radiosensitization by DMC remain uncertain. This study explored the radiosensitizing mechanisms around DMCs in an interdisciplinary approach with cell experiments and Monte Carlo simulation with the PHITS code. Clonogenic survival and nuclear 53BP1 foci of a cell line derived from cervical cancer cells (HeLa cells) were measured post-irradiation with therapeutic X-rays near high-Z materials such as Pb or Au plates, and the experimental sensitizer enhancement ratio (SER) was obtained. Meanwhile, the dose enhancement ratio (DER) and relative biological effectiveness for DNA damage yields were calculated using the PHITS code, by considering the corresponding experimental condition. The experiments show the experimental SER values for cell survival and 53BP1 foci near metals are 1.2-1.4, which agrees well with the calculated DER values. These suggest that the radiosensitizing effects near metal are predominantly attributed to the dose increase. In addition, as a preclinical evaluation, the spatial distributions of DER near DMC are calculated using Computed Tomography Digital Imaging and Communications in Medicine (CT-DICOM) data and a simple tooth model. As a result, the DER values evaluated using the CT-DICOM data were lower than those from a simple tooth model. These findings highlight the challenge of evaluating radiosensitizing effects near DMCs using Digital Imaging and Communications in Medicine (DICOM) images due to volume-averaging effects and emphasize the need for a high-resolution (<1 mm) dose assessment method unaffected by these effects.
X 射线疗法旨在消除肿瘤,同时尽量减少副作用。用牙科金属冠(DMC)照射口腔有时会诱发强烈的粘膜炎。然而,DMC 诱导放射增敏的基本机制仍不确定。本研究采用跨学科方法,通过细胞实验和 PHITS 代码蒙特卡罗模拟,探索了 DMC 的放射致敏机制。实验测量了宫颈癌细胞株(HeLa 细胞)在铅或金板等高 Z 材料附近接受治疗性 X 射线照射后的克隆存活率和核 53BP1 病灶,并得出了实验增敏剂增强比(SER)。同时,考虑到相应的实验条件,利用 PHITS 代码计算了剂量增强比(DER)和 DNA 损伤产率的相对生物有效性。实验结果表明,细胞存活率和金属附近 53BP1 病灶的实验 SER 值为 1.2-1.4,与计算得出的 DER 值十分吻合。这表明金属附近的辐射致敏效应主要归因于剂量的增加。此外,作为临床前评估,利用计算机断层扫描数字成像和医学通信(CT-DICOM)数据和一个简单的牙齿模型,计算了 DMC 附近的 DER 空间分布。结果,使用 CT-DICOM 数据评估的 DER 值低于简单牙齿模型的 DER 值。这些发现凸显了使用医学数字成像和通信(DICOM)图像评估 DMC 附近的放射增敏效应所面临的挑战,因为它具有体积平均效应,并强调了使用高分辨率 (
期刊介绍:
The Journal of Radiation Research (JRR) is an official journal of The Japanese Radiation Research Society (JRRS), and the Japanese Society for Radiation Oncology (JASTRO).
Since its launch in 1960 as the official journal of the JRRS, the journal has published scientific articles in radiation science in biology, chemistry, physics, epidemiology, and environmental sciences. JRR broadened its scope to include oncology in 2009, when JASTRO partnered with the JRRS to publish the journal.
Articles considered fall into two broad categories:
Oncology & Medicine - including all aspects of research with patients that impacts on the treatment of cancer using radiation. Papers which cover related radiation therapies, radiation dosimetry, and those describing the basis for treatment methods including techniques, are also welcomed. Clinical case reports are not acceptable.
Radiation Research - basic science studies of radiation effects on livings in the area of physics, chemistry, biology, epidemiology and environmental sciences.
Please be advised that JRR does not accept any papers of pure physics or chemistry.
The journal is bimonthly, and is edited and published by the JRR Editorial Committee.