一种基于Halcyon加速器的共面容积旋转调强海马保护全脑放疗计划

Coplanar volumetric modulated arc therapy plan for hippocampal avoidance whole-brain radiotherapy implemented on a Halcyon linear accelerator

摘要

目的：比较瓦里安Halcyon、TrueBeam和联影uRT-506c加速器在海马保护全脑放疗中的剂量学差异。方法：选取15例已接受过海马保护全脑放疗的患者进行回顾性分析。分别采用Halcyon、TrueBeam和uRT-506c加速器模型设计共面双弧容积旋转调强放疗（VMAT）计划，准直器角度分别为23°和293°。根据海马位置，将全脑靶区拆分成3个子结构（zPTV_up、zPTV_mid和zPTV_down），给予不同权重参数优化。记录并分析3组计划的靶区（PTV）剂量学参数、危及器官受量和机器跳数的差异。结果：所有患者的VMAT计划均能满足临床治疗标准。Halcyon计划的PTV D_2%、V_{30 Gy}和HI，海马D_100%、D_mean和D_max，晶体和视神经的D_max，均优于TrueBeam和uRT-506c计划，差异有统计学意义（P<0.05）。结论：Halcyon直线加速器在保护海马的全脑放疗中具有更优的剂量分布和可靠的计划计算结果，环形机架既保证了高效的执行效率，又展示出了精准放疗的优势，具有不错的临床应用前景。

Abstract

Objective To compare the dosimetric differences among Varian Halcyon, TrueBeam, and United Imaging uRT-506c linear accelerator in hippocampal avoidance whole-brain radiotherapy. Methods A retrospective analysis was conducted on 15 patients who had previously received hippocampal avoidance whole-brain volumetric modulated arc therapy (VMAT). Dual-arc coplanar VMAT plans were created using the Halcyon, TrueBeam, and uRT-506c accelerator models, with collimator angles of 23° and 293°, respectively. Based on the position of the hippocampus, the whole-brain target volume was divided into 3 substructures (zPTV_up, zPTV_mid, and zPTV_down), each optimized using different weight factors. The dosimetric parameters of the planning target volume, organ-at-risk doses, and monitor unit in the 3 groups were recorded and analyzed. Results VMAT plans for all patients satisfied clinical treatment criteria. Halcyon plans were superior to True Beam and uRT-506c plans in the D_2%, V_{30 Gy}, and HI of planning target volume, the D_100%, D_mean, and D_max of the hippocampus, as well as the D_max of the lens and optic nerves, with statistically significant differences (P<0.05). Conclusion For hippocampus avoidance whole-brain radiotherapy, the Halcyon linear accelerator delivers superior dose distribution and robust plan calculation results, and its ring gantry ensures efficient treatment delivery while highlighting the strengths of precise radiotherapy, showing great potential for clinical practice.

关键词

Halcyon加速器 / 海马保护 / 全脑放疗 / 容积旋转调强

Key words

Halcyon accelerator / hippocampus avoidance / whole-brain radiotherapy / volumetric modulated arc therapy

参考文献

[1] Brown PD, Ahluwalia MS, Khan OH, et al. Whole—brain radiotherapy for brain metastases: evolution or revolution?[J]. J Clin Oncol, 2018, 36(5): 483-491.

[2] Sperduto PW, Kased N, Roberge D, et al. Effect of tumor subtype on survival and the graded prognostic assessment for patients with breast cancer and brain metastases[J]. Int J Radiat Oncol Biol Phys, 2012, 82(5): 2111-2117.

[3] Gore EM, Bae K, Wong SJ, et al. Phase III comparison of prophylactic cranial irradiation versus observation in patients with locally advanced non—small—cell lung cancer: primary analysis of radiation therapy oncology group study RTOG 0214[J]. J Clin Oncol, 2011, 29(3): 272-278.

[4] Tallet AV, Azria D, Barlesi F, et al. Neurocognitive function impairment after whole brain radiotherapy for brain metastases: actual assessment[J]. Radiat Oncol, 2012, 7: 77.

[5] Gondi V, Pugh SL, Tome WA, et al. Preservation of memory with conformal avoidance of the hippocampal neural stem—cell compartment during whole—brain radiotherapy for brain metastases (RTOG 0933): a phase II multi—institutional trial[J]. J Clin Oncol, 2014, 32(34): 3810-3816.

[6] 苏洁洪, 魏夏平, 周子涵, 等 . Halcyon直线加速器在鼻咽癌放疗中靶区外放边界及摆位误差分析[J]. 中国医学物理学杂志, 2023, 40(12): 1459-1462.

[7] Su JH, Wei XP, Zhou ZH, et al. Target volume margins and positioning errors in radiotherapy for nasopharyngeal carcinoma using Halcyon linear accelerator[J]. Chinese Journal of Medical Physics, 2023, 40(12): 1459-1462.

[8] 黄元彤, 许青, 李乾永, 等 . Halcyon 3.0加速器在乳腺癌放射治疗中的精度分析: 摆位误差与移床差量的相关性研究[J]. 中国医疗器械信息, 2025, 31(20): 1-3.

[9] Huang YT, Xu Q, Li QY, et al. Precision analysis of halcyon 3.0 accelerator in breast cancer radiotherapy: a correlation study between setup errors and couch shifts[J]. China Medical Device Information, 2025, 31(20): 1-3.

[10] 祝起禛, 杨波, 汪之群, 等 . 基于Halcyon 2.0和Truebeam的多部位VMAT计划剂量学质量与复杂度综合对比研究[J]. 中华放射肿瘤学杂志, 2023, 32(3): 241-247.

[11] Zhu QZ, Yang B, Wang ZQ, et al. Comprehensive comparison between Halcyon 2.0 and Truebeam VMAT plans for different treatment sites: dosimetric quality and plan complexity[J]. Chinese Journal of Radiation Oncology, 2023, 32(3): 241-247.

[12] 曾宏伟, 张瑜, 鄂翔宇, 等 . 基于Halcyon 3.0海马保护全脑放疗计划中不同子野调制参数的剂量学评估[J]. 中华放射医学与防护杂志, 2023, 43(9): 682-688.

[13] Zeng HW, Zhang Y, E XY, et al. Dosimetric evaluation of different aperture shape controller parameters based on the Halcyon 3.0 accelerator in the hippocampal avoidance—whole brain radiotherapy[J]. Chinese Journal of Radiological Medicine and Protection, 2023, 43(9): 682-688.

[14] 胡俏俏, 吴昊, 蒋藩, 等 . 瓦里安Halcyon加速器的安装验收测试[J]. 中华放射肿瘤学杂志, 2021, 30(7): 712-716.

[15] Hu QQ, Wu H, Jiang F, et al. Installation product acceptance of Varian Halcyon accelerator[J]. Chinese Journal of Radiation Oncology, 2021, 30(7): 712-716.

[16] 尹楚欧, 邓娟, 梅国建, 等 . Halcyon加速器在乳腺癌保乳术后放射治疗中的临床应用[J]. 生物医学工程与临床, 2024, 28(5): 641-646.

[17] Yin CO, Deng J, Mei GJ, et al. Clinical application of radiotherapy for breast cancer after breast—conserving surgery on Halcyon accelerator[J]. Biomedical Engineering and Clinical Medicine, 2024, 28(5): 641-646.

[18] Tang R, Li AM, Li YJ, et al. Dosimetric comparison of two dose expansion methods in intensity modulated radiotherapy for breast cancer[J]. Radiat Oncol, 2023, 18(1): 23.

[19] Oskan F, Ganswindt U, Schwarz SB, et al. Hippocampus sparing in whole—brain radiotherapy[J]. Strahlenther Onkol, 2014, 190(4): 337-341.

[20] Zhang HW, Hu B, Pang HW . Dosimetric comparison of helical tomotherapy and volumetric modulated arc therapy in hippocampal avoidance whole—brain radiotherapy[J]. J Appl Clin Med Phys, 2024, 25(1): e14218.

[21] Gondi V, Tolakanahalli R, Mehta MP, et al. Hippocampal—sparing whole—brain radiotherapy: a "how—to" technique using helical tomotherapy and linear accelerator—based intensity—modulated radiotherapy[J]. Int J Radiat Oncol Biol Phys, 2010, 78(4): 1244-1252.

[22] Hernandez V, Saez J, Angerud A, et al. Dosimetric leaf gap and leaf trailing effect in a double—stacked multileaf collimator[J]. Med Phys, 2021, 48(7): 3413-3424.

[23] Lim TY, Dragojević I, Hoffman D, et al. Characterization of the halcyon(TM) multileaf collimator system[J]. J Appl Clin Med Phys, 2019, 20(4): 106-114.

[24] Li YH, Chen LX, Zhu JH, et al. A quantitative method to the analysis of MLC leaf position and speed based on EPID and EBT3 film for dynamic IMRT treatment with different types of MLC[J]. J Appl Clin Med Phys, 2017, 18(4): 106-115.

[25] Vorwerk H, Wagner D, Hess CF . Impact of different leaf velocities and dose rates on the number of monitor units and the dose—volume—histograms using intensity modulated radiotherapy with sliding—window technique[J]. Radiat Oncol, 2008, 3: 31.

[26] Rong Y, Evans J, Xu—Welliver M, et al. Dosimetric evaluation of intensity—modulated radiotherapy, volumetric modulated arc therapy, and helical tomotherapy for hippocampal—avoidance whole brain radiotherapy[J]. PLoS One, 2015, 10(4): e0126222.

[27] Takaoka T, Tomita N, Mizuno T, et al. Dosimetric comparison of helical tomotherapy and intensity—modulated proton therapy in hippocampus— and scalp—sparing whole brain radiotherapy[J]. Technol Cancer Res Treat, 2021, 20: 15330338211060170.

[28] Nevelsky A, Ieumwananonthachai N, Kaidar—Person O, et al. Hippocampal—sparing whole—brain radiotherapy using Elekta equipment[J]. J Appl Clin Med Phys, 2013, 14(3): 4205.

[29] Xue J, Jin SN, Zhang HT, et al. A simplified non—coplanar volumetric modulated arc therapy for the whole brain radiotherapy with hippocampus avoidance[J]. Front Oncol, 2023, 13: 1143564.

[30] Sun WJ, Chen KZ, Li Y, et al. Optimization of collimator angles in dual—arc volumetric modulated arc therapy planning for whole—brain radiotherapy with hippocampus and inner ear sparing[J]. Sci Rep, 2021, 11(1): 19035.

[31] Fu Q, Chen DQ, Yan H, et al. Treatment planning of volumetric modulated arc therapy and positioning optimization for hippocampal—avoidance prophylactic cranial irradiation[J]. J Appl Clin Med Phys, 2021, 22(5): 15-23.

基金资助

广东省医学科研基金(A2023250)