MR加速器在肺癌放疗中的应用及基本应用流程北大核心CSCD

放疗是肿瘤治疗的重要手段之一。图像引导放疗是目前实现肿瘤精准放疗的主流技术。MR加速器能在放疗过程中对肿瘤进行MRI, 实现肿瘤的实时追踪与监控, 完成MR引导的自适应放疗。本文将综述MR加速器在肺癌中的相关研究与应用。     

MR加速器在乳腺癌放疗中的临床应用北大核心CSCD

目的介绍MR加速器应用于乳腺癌术前放疗的应用流程和注意事项, 并报告不良反应。方法中国医学科学院肿瘤医院拟开展一项单臂、Ⅱ期临床研究, 入组患者实施MR加速器下术前瘤床补量, 2周内进行保乳手术, 术后6周内接受辅助全乳照射, 研究终点为≥2级急性不良反应。首例应用MR加速器术前放疗乳腺癌患者43岁, 为右乳外象限浸润性癌, cT_(2)N_(0)M_(0)期, AJCC第8版ⅡA期。患者接受CT和MR定位、MR指导下靶区勾画、Monaco系统计划设计, MR加速器下摆位并基于位移适应调整, 单次8 Gy照射。患者的剂量计算考虑了1.5 T磁场存在下的电子回旋效应(ERE)及电子束效应(ESE)。结果首例患者治疗顺利, 计划的正常器官满足限量要求, 因ERE及ESE导致的皮肤剂量增加幅度不大(D_(max) 8.44 Gy), 下颌及右上臂受量均很低(D_(max) 28.5、17.8 cGy), 无>1级急性不良反应。患者放疗后第7天接受保乳术, 未出现严重手术并发症, 伤口愈合及时。结论 1.5 T磁场对皮肤、下颌和手臂的剂量影响较小, 放疗及放疗后手术均无明显并发症增加。MR加速器下乳腺癌的放疗尚需更大样本的经验积累, 以不断优化治疗流程。     

MR加速器在肝脏肿瘤放疗中的临床应用北大核心CSCD

目的初步探讨MR加速器在肝脏肿瘤中的应用流程、疗效及安全性。方法回顾性分析2019—2021年15例采用MR加速器治疗的肝脏肿瘤患者的临床数据, 探讨肝脏肿瘤采用MR加速器治疗的流程, 分析患者肿瘤的图像识别率、疗效及不良反应。结果全组15例患者中肝细胞癌6例、结直肠癌肝转移8例、乳腺癌肝转移1例;肝内1个病灶10例、2个病灶4例、3个病灶1例;中位肿瘤最长径2.4 cm (0.8~9.8 cm)。MR加速器大体肿瘤体积(GTV)识别率达13/15, 2例患者GTV显示不清, 采用肿瘤周边大血管或胆管识别辅助仍可达精准配准。全组患者均接受体部立体定向放疗。肝细胞癌患者中位分割次数9次(5~10次), GTV或计划靶体积(PGTV)中位单次剂量6 Gy (5~10 Gy), 中位总剂量52 Gy (50~54 Gy), α/β=10的中位2 Gy等效剂量(EQD2Gy)为72 Gy (62.5~83.3 Gy)。肝转移瘤患者中位分割次数10次(5~10次), GTV或PGTV的中位单次剂量5 Gy (5~10 Gy), 中位总剂量50 Gy (40~50 Gy), α/β=5的中位EQD2Gy为71.4 Gy (71.4~107.1 Gy)。放疗后1个月野内总有效率8/13, 疾病控制率13/13, 放疗后3~6个月野内总有效率6/6。全组患者中位随访4.0个月(0.3~11.6个月), 4个月局部无进展生存、无进展生存和总生存分别为15/15、11/15和15/15。放疗不良反应轻微, 未见≥3级不良反应。结论 MR加速器对肝内肿瘤显示率高, 且可通过周边大血管或胆管的显示辅助精准配准, 在肝脏肿瘤的精准治疗上初步展现优势, 局部疗效肯定, 耐受性好。     

自适应放疗在头颈部肿瘤治疗中的应用

头颈部肿瘤在放疗过程中每次治疗时的靶区位置和形状都会存在差异,为了避免造成靶区漏照或正常组织受到过多照射,精确放疗的准确性显得尤为重要。自适应放疗(adaptive radiation therapy,ART)是在三维适形放疗(3D-CRT)和调强放射治疗(IMRT)基础上出现的新型放疗技术,它是图像引导放射治疗(IGRT)的进一步提高和发展。治疗实施通过患者图像、剂量等反馈信息对原治疗计划重新优化和调整,这是一种基于反馈控制理论的治疗策略。其目的是使放射治疗更加精确化、个体化。     

自适应放疗在头颈部肿瘤治疗中的应用

头颈部肿瘤在放疗过程中每次治疗时的靶区位置和形状都会存在差异,为了避免造成靶区漏照或正常组织受到过多照射,精确放疗的准确性显得尤为重要。自适应放疗（adaptive radiation therapy,ART）是在三维适形放疗（3D-CRT）和调强放射治疗（IMRT）基础上出现的新型放疗技术,它是图像引导放射治疗（IGRT）的进一步提高和发展。治疗实施通过患者图像、剂量等反馈信息对原治疗计划重新优化和调整,这是一种基于反馈控制理论的治疗策略。其目的是使放射治疗更加精确化、个体化。     

MR引导放疗在胰腺癌中的应用

放疗是治疗胰腺癌的重要手段。但受胰腺运动等因素影响,放疗疗效难以充分发挥。更高效的胰腺癌放疗有赖于运动管理方式的改进与高质量的图像引导。新兴的MR引导放疗技术软组织分辨率高、无额外辐射、能进行功能成像,经过大量研究评估与验证,其在靶区与危及器官的精准勾画、辅助运动管理和自适应放疗等方面有着巨大优势,有望更好地发挥放疗在...     

MR引导的放疗系统临床应用

目的:探讨MR引导的Unity放疗系统在临床应用中的可行性。方法:临床试验入选24例患者,按治疗部位分为头颈组、胸腹组、盆腔组、脊柱组和肢体组,总共384个治疗分次。在无外置激光的情况下进行摆位,统计在线治疗流程中不同阶段所需时间和每个分次的配准误差。每周利用MR几何形变模体检测MR图像几何形变大小。并利用ArcChe...     

Unity MR加速器临床应用各阶段时间统计分析北大核心CSCD

目的探索Unity MR加速器放疗系统在临床应用中各阶段的时间特征,为临床优化流程时间提供参考。方法回顾性研究使用Unity MR加速器治疗的患者55例,根据治疗计划方式分为位置自适应(ATP)和形状自适应(ATS)两组,统计对比两种治疗流程中各阶段所需时间、各部位的扫描序列名称和序列所需时长、计划射野数、子野数及跳数。此外,按治疗部位不同统计摆位时间。两种流程各分步时间及各部位摆位时间的结果采用中位数M(Q_(1),Q_(3))方式描述,各计划的子野数、射野数及跳数采用Mean±SD方式描述。结果行ATP治疗流程42例,共计305治疗分次:摆位、MR扫描、配准、自适应计划、出束、总时间分别为3(2,5)、5(4,7)、3(3,4)、8(4,12)、8(6,11)、30(25,36)min;行ATS治疗流程13例,共计65治疗分次:摆位、MR扫描、配准、靶区及OAR勾画、自适应计划、出束、总时间分别为2(2,3)、7(5,8)、4(3,5)、12(9,16)、11(10,14)、10(9,11)、55(49,61)min。按治疗部位统计摆位时间:头颈、胸、腹部分别为4(2,4)、2(2,4)、3(2,5)min;行ATP各计划的子野数、射野数及跳数分别为:头颈部8.1±1.7、49.9±31.2、846.75±363.44 MU,胸部8.0±2.0、60.7±13.3、790.21±279.00 MU,腹部9.7±2.0、81.2±22.3、2007.32±1053.81 MU;行ATS计划的子野数、射野数及跳数分别为:头颈部(仅1例)13、39、993.07 MU,腹部9.5±1.5、65.5±6.3、2763.26±835.41 MU。结论MR引导放疗具有较大临床应用潜力,目前整体治疗时间较长,但仍有改进的空间。     

基于MR引导放疗系统肺癌SBRT初步临床应用

目的:初步观察MR引导下非小细胞肺癌体部立体定向放疗(SBRT)的可行性,并对有无磁场环境下剂量学差异进行分析。方法:前瞻性的入组3例SBRT的非小细胞肺癌患者,均应用MR引导加速器放疗。治疗计划分别应用有磁场模型和无磁场模型进行优化和剂量计算,同时在常规加速器进行患者备用计划的制备。比较有无磁场模型剂量的分布差异。同...     

头颈部肿瘤自适应放疗的研究进展

调强放射治疗(intensity-modulated radiation therapy,IMRT)是头颈部恶性肿瘤的重要治疗方法之一。但在IMRT过程中,摆位误差、解剖结构的移位及变形、肿瘤退缩或进展及形状改变等,可导致靶区和危及器官的照射剂量和体积出现“偏差”,影响IMRT的精确性。图像引导的放射治疗(image-guidedradiotherapy,IGRT)可部分纠正摆位误差,从而提高放疗精度,但不能解决非刚性误差以及解剖结构变化带来的剂量差异。自适应放射治疗(adaptive radiation therapy,ART)是在IMRT和IGRT基础上出现的新型放疗技术,能修正IMRT和IGRT靶区和危及器官的偏差。通过患者图像、剂量等反馈信息对原治疗计划重新优化和调整,这是一种基于反馈控制理论的治疗策略。其目的是使放射治疗更加精确化、个体化。     

头颈部肿瘤IMRT中适应性再计划预测因素和时间节点的研究进展

在头颈部肿瘤IMRT疗程中,适应性再计划有助于改善由于解剖结构变化导致的剂量学不确定性,并能提高患者的局部控制率和生活质量。研究表明患者治疗前有较大淋巴结、治疗中体重明显下降等是疗程中再计划的重要预测因素;在放疗开始第4周后靶区及危及器官的缩小趋于稳定,建议第3或第4周行 1~2次适应性再计划。     

头颈部肿瘤放疗者营养与支持治疗专家共识

放疗是头颈部肿瘤最常用的治疗手段。恶性肿瘤本身代谢异常及治疗过程中伴随的急性和晚期毒性等极易导致患者发生营养不良,其发生率高达44%~88%,其中重度营养不良的发生率为20%~40%。患者一旦发生营养不良,其治疗耐受性和敏感性会降低,治疗并发症会进一步增高,从而延长住院时间增加治疗费用,最终影响患者疗效。因此,营养与支持治疗是头颈肿瘤患者治疗的重要组成部分。为了使这部分患者得到合理、有效的营养与支持治疗,根据我国目前的肿瘤放疗和肿瘤营养治疗现状,参考国内外相关指南,制定适合我国情况的头颈部肿瘤放疗患者营养与支持治疗专家共识非常必要。     

Intensity-modulated radiation therapy for head and neck cancer: Systematic review and meta-analysis

Background and purpose

Intensity-modulated radiation therapy (IMRT) provides the possibility of dose-escalation with better normal tissue sparing. This study was performed to assess whether IMRT can improve clinical outcomes when compared with two-dimensional (2D-RT) or three-dimensional conformal radiation therapy (3D-CRT) in patients with head and neck cancer.

Methods and materials

Only prospective phase III randomized trials comparing IMRT with 2D-RT or 3D-CRT were eligible. Combined surgery and/or chemotherapy were allowed. Two authors independently selected and assessed the studies regarding eligibility criteria and risk of bias.

Results

Five studies were selected. A total of 871 patients were randomly assigned for 2D-RT or 3D-CRT (437), versus IMRT (434). Most patients presented with nasopharyngeal cancers (82%), and stages III/IV (62.1%). Three studies were classified as having unclear risk and two as high risk of bias. A significant overall benefit in favor of IMRT was found (hazard ratio – HR = 0.76; 95% CI: 0.66, 0.87; p < 0.0001) regarding xerostomia scores grade 2–4, with similar loco-regional control and overall survival.

Conclusions

IMRT reduces the incidence of grade 2–4 xerostomia in patients with head and neck cancers without compromising loco-regional control and overall survival.     

影像组学在头颈部肿瘤放疗的研究进展

头颈部肿瘤具有复杂的解剖和高度的异质性,放疗是主要的治疗手段之一,治疗策略和预后评估往往依据TNM分期,缺乏个体化的参考信息。影像组学高通量的提取与肿瘤生物学有关的图像特征,用于无创定量评价整体肿瘤的异质性,为实现精准放疗开拓了新的途径。本文将介绍影像组学近年来在头颈部肿瘤放疗的应用和挑战。     

Randomized trial of conventional versus high fractional dose radiation therapy in the treatment of advanced head and neck cancer

A prospectively randomized clinical trial was undertaken to compare conventionally fractionated radiation therapy and high fractional dose irradiation in the treatment of advanced, surgically unresectable head and neck squamous cell carcinoma. Sixty-four patients were entered into the study between 1973 and 1979 and were randomized to receive either 200 rad daily to total tumor doses of 6000-7000 rad in 6-7 weeks, or 400 rad daily to a total of approximately 4400 rad in 2-3 weeks. The distribution of patients between the two fractionation schedules was comparable regarding site of the primary tumor, extent of disease, degree of histologic differentiation and performance status. Twenty-nine of 31 (94%) patients in the 200 rad group and 29 of 33 (88%) in the 400 rad group has Stage IV disease. Twenty-six in the former group and 30 in the latter completed radiation therapy as planned. Acute skin and mucosal reactions occurred earlier in patients treated with 400 rad daily, but were of equivalent intensity and well within acceptable levels in both groups. No increase in late adverse effects was seen with high daily doses. Palliation of tumor-related symptoms and extent of tumor control were comparable in the two groups. Actuarial five year disease-free survival rates were approximately 10% in both treatment groups with a mean follow-up period of 5 1/2 years. We conclude that high fractional dose irradiation is equivalent to conventionally fractionated radiation therapy in the treatment of advanced head and neck cancer.     

The function of the parotid gland following radiation therapy for head and neck cancer

The parotid gland was selected for study of its salivary output before and after radiation therapy for head and neck cancer. Before radiation therapy, a sialogram of the parotid gland was performed with the patient's head positioned for radiation therapy; a lateral radiographic view of the parotid gland was used to compare with the radiation treatment portal to determine the portion of the parotid gland to he irradiated. Samples of stimulated saliva were collected from the parotid gland before and at 1 and 6 months post-radiation. Eighteen patients with head and neck cancer who received radiation therapy were studied. The data showed that in the irradiation of nasopharyageal, advanced oropbaryngeal and Waldeyer's ring lesions, 100% of the parotid gland was irradiated; for the early oropharyageal and hypopbaryugeal lesions, from 30 to 90% of the parotid gland was irradiated and for the supragiottic and oral cavity lesions, 25–30% of the parotid gland was irradiated. When 100% of the parotid gland was irradiated, no saliva was produced at 1 month post-radiation; this remained the same when re-tested at 4–8 months, however, when any portion of the parotid gland was not irradiated, there was residual salivary function.