应用密度填充及伪影消减技术提高带金属植入物患者IMRT剂量准确度研究

doi:10.3760/cma.j.cn113030-20190801-00012

摘要
图/表
参考文献(16)
相关文章 (10)
点击分布统计
下载分布统计

全文: PDF (0 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS) 背景资料

摘要目的探讨提高带金属植入物患者放射治疗计划剂量计算准确度的方法。方法利用具有金属伪影消减技术的CT模拟机对插入金属棒的CIRS调强模体和8例椎体中植入了钢钉并接受放疗的患者进行扫描,在获得的常规CT图像、金属伪影消减技术CT图像及对其金属区域进行密度填充的图像上设计治疗计划。在模体中比较单个射野及IMRT计划的计算结果与剂量测量结果,同时对患者IMRT计划中金属植入物及其伪影对照射剂量产生的影响进行分析。结果基于常规CT图像的放疗计划中,射野入射路径未通过金属区域时,单个射野的剂量计算误差为3.85%,通过金属区域时射野计算误差范围达4.46%~74.11%。IMRT计划中存在入射路径通过金属区域的射野时,其误差可能超出临床可接受的范围,计算误差随这种射野所占剂量权重的增加而变大。当采用密度填充及伪影消减技术处理图像后,上述单个射野的计算误差分别为1.23%和0.89%~4.73%,IMRT计划的剂量误差为1.84%。若单独采用密度填充技术处理金属区域,IMRT计划的剂量误差为1.88%。基于常规CT图像的患者IMRT计划中,受金属植入物及其伪影的影响,实际靶区受到的最小剂量、平均剂量及处方剂量覆盖率较计划结果下降,危及器官剂量相近。结论基于常规CT图像的放疗计划中,入射路径通过金属区域的射野可能产生较大的剂量计算误差。如果植入的金属材料已知,在计划系统中对金属区域进行密度填充能有效提高计划的剂量计算准确度。伪影消减技术能显著改善图像质量,进一步减少剂量计算误差,对于配备这种功能的CT机进行带金属植入物患者的模拟定位时应作为常规技术。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	赵培峰
	周钢
	孙彦泽
	杨咏强
	邢鹏飞

关键词 ：金属植入物, 调强放射治疗, 剂量计算, 准确度

Abstract：Objective To explore the method of improving the accuracy of dose calculation of treatment plan in radiotherapy for patients with metal implants. Methods A CT simulator with metal artifact reduction technique (MAR) was utilized to scan the CIRS intensity-modulated phantom with metal rods and 8 patients with steel nails implanted in the centrum for radiotherapy. Radiotherapy plans were designed using conventional CT images, MAR images and density-filled images. The dose calculation errors between single field and intensity-modulated radiotherapy (IMRT) plan were compared. The effect of mental implants and their artifacts on the irradiation dose of IMRT plan was evaluated. Results In the conventional CT images of the phantom, when the incident path of the field failed to pass through the metal region, the dose calculation error for a single field was 3.85%, and the range of dose error for the field was 4.46%-74.11% when passing through the metal region. IMRT planning errors might exceed the clinically acceptable range when the incident path of the field passed through the metal region, and the errors tended to increase with the increase of dose weight of this field. After processing the images with density filling and artifact reduction techniques, the errors of the single field were 1.23% and 0.89%-4.73%, respectively, and the dose error of IMRT was 1.84%. The error of IMRT plan was 1.88% if density filling technique alone was employed to process the metal region. Due to the influence of metal implants and their artifacts, the minimum dose, average dose and prescription dose coverage actually received in the tumor target area were lower than IMRT plan results based on conventional CT images. The dosimetric difference of organs at risk was not statistically significant. Conclusions In the radiotherapy plan based on conventional CT images, there may be a large dose calculation error when the incident path of field passes through the metal region. If the metal material is known, density filling of the metal region in the planning system can effectively improve the accuracy of dose calculation. Metal artifact reduction technique can significantly improve the image quality and further reduce dose calculation error, which should be a routine technique for CT machines equipped with this function to perform simulated localization of patients with metal implants.

Key words： Metal implant Intensity-modulated radiotherapy Dose calculation Accuracy

收稿日期: 2019-08-01

基金资助:江苏省医学创新团队(CXDT-37);苏州市科技发展计划项目(SS201642)

通讯作者: 周钢,Email:zhougang0626@163.com

引用本文:

赵培峰,周钢,孙彦泽等. 应用密度填充及伪影消减技术提高带金属植入物患者IMRT剂量准确度研究[J]. 中华放射肿瘤学杂志, 2020, 29(5): 378-382.

Zhao Peifeng,Zhou Gang,Sun Yanze et al. Study of improving IMRT dose accuracy in patients with metal implants by density filling and artifact reduction[J]. Chinese Journal of Radiation Oncology, 2020, 29(5): 378-382.

链接本文:

http://journal12.magtechjournal.com/Jweb_fszlx/CN/10.3760/cma.j.cn113030-20190801-00012 或 http://journal12.magtechjournal.com/Jweb_fszlx/CN/Y2020/V29/I5/378

[1] Axente M, Paidi A, Von Eyben R, et al. Clinical evaluation of the iterative metal artifact reduction algorithm for CT simulation in radiotherapy[J]. Med Phys, 2015, 42(3):1170-1183. DOI:10.1118/1.4906245.
[2] Kim C, Pua R, Lee CH, et al. An additional tited-scan-based CT metal-artifact-reduction method for radiation therapy planning[J]. J Appl Clin Med Phys, 2019, 20(1):237-249. DOI:10.1002/acm2.12523.
[3] Giantsoudi D, De Man B, Verburg J, et al. Metal artifacts in computed tomography for radiation therapy planning:dosimetric effects and impact of metal artifact reduction[J]. Phys Med Biol, 2017, 62(8):R49-R80. DOI:10.1088/1361-6560/aa5293.
[4] Ziemann C, Stille M, Cremers F, et al. Improvement of dose calculation in radiation therapy due to metal artifact correction using the augmented likelihood image reconstruction[J]. J Appl Clin Med Phys, 2018, 19(3):227-233. DOI:10.1002/acm2.12325.
[5] Huang JY, Followill DS, Howell RM, et al. Approaches to reducing photo dose calculation errors near metal implants[J]. Med Phys, 2016, 43(9):5117-5130. DOI:10.1118/1.4960632.
[6] 张若辉,白文文,樊晓妹,等. Monaco计划系统中构建治疗床模型对放疗剂量控制意义探讨[J]. 中华肿瘤防治杂志, 2016, 23(2):105-109. DOI:10.16073/j.cnki.cjcpt.2016.02.013.
Zhang RH, Bai WW, Fan XM, et al. Significance of modeling the treatment couch in the Monaco treatment planning system for dose control of radiotherapy[J]. Chin J Cancer Prev Treat, 2016, 23(2):105-109. DOI:10.16073/j.cnki.cjcpt.2016.02.013.
[7] 林涛,倪昕晔,高留刚,等. 对金属植入物模体不同剂量计算方法研究[J]. 中华放射肿瘤学杂志,2018, 27(7):680-684. DOI:10.3760/cma.j.issn.1004-4221.2018.07.012.
Lin T, Ni XY, Gao LG, et al. Study of different dose calculationalgorithms for the phantom of metallic implants[J]. Chin J Radiat Oncol, 2018, 27(7):680-684. DOI:10.3760/cma.j.issn.1004-4221.2018.07.012.
[8] Ni XY, Gao LG, Fang MM, et al. Application of metal implant 16-bit imaging:new technique in radiotherapy[J]. Technol Cancer Res Treat, 2017,16(2):188-194. DOI:10.1177/1533034616649530.
[9] Maerz M, Mittermair P, Krauss A, et al. Iterative metal artifact reduction improves dose calculation accuracy:Phantom study with dental implants[J]. Strahlenther Onkol, 2016, 192(6):403-413. DOI:10.1007/s00066-016-0958-z.
[10] Li H, Noel C, Chen H, et al. Clinical evaluation of a commercial orthopedic metal artifact reduction tool for CT simulation in radiation therapy[J]. Med Phys, 2012, 39(12):7507-7517. DOI:10.1118/1.4762814.
[11] 高留刚,孙鸿飞,谢凯,等. 基于12和16 bit CT图像的金属伪影校正对放疗剂量分布的影响[J]. 中华放射医学与防护杂志, 2017, 37(12):938-945. DOI:10.3760/cma.j.issn. 0254-5098.2017.12.012.
Gao LG, Sun HF, Xie K, et al. Effect of metal artifact correction based on 12 and 16 bit CT images on dose distribution in radiotherapy[J]. Chin J Radiol Med Prot, 2017, 37(12):983-945. DOI:10.3760/cma.j.issn. 0254-5098.2017.12.012.
[12] Ohira S, Washio H, Yaqi M, et al. Estimation of electron density, effective atomic number and stopping power ratio using dual-layer computed tomography for radiotherapy treatment planning[J]. Phys Med, 2018, 56:34-40. DOI:10.1016/j.ejmp.2018.11.008.
[13] Mei K, Ehn S, Oechsner M, et al. Dual-layer spectral computed tomography:measuring relative electron density[J]. Eur Radiol Exp, 2018, 2:20. DOI:10.1186/s41747-018-0051-8.
[14] Lin MH, Li J, Price RA, et al. The dosimetric impact of dental implants on head-and-neck volumetric modulated arc therapy[J]. Phys Med Biol, 2013,58(4):1027-1040. DOI:10.1088/0031-9155/58/4/1027.
[15] Hansen CR, Christiansen RL, Lorenzen EL, et al. Contouring and dose calculation in head and neck cancer radiotherapy after reduction of metal artifacts in CT images[J]. Acta Oncol, 2017,56(6):874-878. DOI:10.1080/0284186X.2017.12.
[16] 赵培峰,孙彦泽,周钢. 带金属植入物患者调强放射治疗计划中射野角度设置对剂量计算准确度的影响[J]. 中国医学物理学杂志, 2019, 36(8):882-886. DOI:10.3969/j.issn.1005-202X.2019.08.004.
Zhao PF, Sun YZ, Zhou G. Effect of field angle setting on dose calculation accuracy in intensity-modulated radiotherapy plans for patients with metal implants[J]. Chin J Med Phys, 2019,36(8):882-886. DOI:10.3969/j.issn.1005-202X.2019.08.004.