Organ motion in image-guided radiotherapy: lessons from real-time tumor-tracking radiotherapy

External radiotherapy using imaging technology for patient setup is often called image-guided radiotherapy (IGRT). The most important problem to solve in IGRT is organ motion. Four-dimensional radiotherapy (4DRT), in which the accuracy of localization is improved – not only in space but also in time – in comparison to 3DRT, is required in IGRT. Real-time tumor-tracking radiotherapy (RTRT) has been shown to be feasible for performing 4DRT with the aid of a fiducial marker near the tumor. Lung, liver, prostate, spinal/paraspinal, gynecological, head and neck, esophagus, and pancreas tumors are now ready for dose escalation studies using RTRT.     

国产威达（WD－H·D·R18）后装腔内治疗机的临床应用（附380例疗效观察）

我院自１９９２年６月至１９９３年６月使用广东威达（ＷＤ·Ｈ·Ｄ·Ｒ·１８型）后装腔内治疗机，施行腔内放疗、组织间插植、术中置管和表面敷贴放疗等方法，治疗各种癌瘤共３８０例，其近期疗效为：完全消失７９．７４％（３０３／３８０）部分消失：１４．７４％（５６／３８０）无效：５．５３％（２１／３８０）；总有效率：９４．４８％（３５９／３８０）。全组随诊时间为１－１２个月。结合临床应用的若干问题对该机作出初步评价。     

2019年中国大陆地区放疗人员和设备基本情况调查研究

[目的]了解我国大陆地区放疗人才及设备情况。[方法]2019年4月10日至9月20日期间,中华医学会放射肿瘤治疗学分会通过线上问卷的形式进行了全国第九次行业调查,调查2018年度全国各个医院从事放疗的人员、设备、技术、年放疗人次以及主要放疗病种等数据。[结果]本次问卷回收率100%,所有放疗单位数据通过各省医学会再次确认。中国大陆地区放疗单位1463家。从事放疗的工作人员共29096人,其中放疗医师14575人、物理师4172人、技师8940人、维修师1409人。共有直线加速器2021台(含进口和国产),钴60远距离治疗机66台,近距离治疗机339台,质子重离子机5台,常规模拟机1453台,CT模拟机355台。能开展二维放疗1002家,三维适形放疗1272家,静态调强放疗1121家,Rapid Arc145家,容积旋转调强放疗279家,立体定向放射治疗297家,近距离治疗273家,全身X线治疗75家,全身电子线治疗73家,Tomo治疗38家,质子/重离子治疗5家。病床数97836张(含综合医院肿瘤科病床),放疗年治疗人数1259602人。[结论]中国大陆地区放疗单位数目缓慢增长,放疗从业人员较前稍减少,开展放疗新技术单位逐年增加,全国每百万人口放疗设备(加速器+钴60)仅1.5,仍低于WHO的要求。     

Clinician's guide to prostate IMRT plan assessment and optimisation

Intensity-modulated radiotherapy (IMRT) offers dosimetric benefit for irregularly shaped treatment volumes compared to three-dimensional conformal approaches. Some groups advocate IMRT as the standard of care for prostate radiotherapy. For clinicians, assessment of an IMRT plan can introduce new opportunities and challenges. Although a standard IMRT plan may be deemed acceptable by meeting pre-set dose constraints, further optimisation may yield a superior treatment plan by further reducing dose to critical structures or improving target volume homogeneity. The aim of this article is to present aspects of IMRT planning relevant to clinicians to aid in plan critiquing.     

Evaluation of a Novel Field-placement Algorithm for Locoregional Breast Cancer Radiotherapy Including the Internal Mammary Chain

Aims

Irradiation of the internal mammary chain (IMC) is increasing following recently published data, but the need for formal delineation of lymph node volumes is slowing implementation in some healthcare settings. A field-placement algorithm for irradiating locoregional lymph nodes including the IMC could reduce the resource impact of introducing irradiation of the IMC. This study describes the development and evaluation of such an algorithm.

非小细胞肺癌3D-CRT与IMRT立体定向放疗剂量学比较

目的:研究三维适形(3D-CRT)和逆向调强(IMRT)两种计划方式在进行早期非小细胞肺癌(NSCLC)立体定向放射治疗(SBRT)的剂量学差异。方法:选取接受放射治疗的早期NSCLC患者12例,分别采用3D-CRT和IMRT技术设计SBRT治疗计划。比较两种计划方式下PTV的相关剂量学参数(CI、HI、D1%、D99%),肺、胸壁、心脏及脊髓的剂量学参数(Vx、Dmean、Dmax),以及加速器的机器跳数、治疗时间等差异。结果:在PTV相关参数比较中,3D-CRT计划的CI、HI以及D1%均差于IMRT,差异有统计学意义,P<0.05;但是两者的D99%差异无统计学意义,P>0.05。在危及器官受量的比较中,3D-CRT与IMRT计划的患侧肺V5～V40、健侧肺V5～V15、双侧肺V5～V40、胸壁V5～V40、Dmean、心脏V20～V40、Dmean及脊髓Dmax的差异均无统计学意义,P>0.05。3D-CRT计划的机器跳数及治疗时间较IMRT计划分别减少了53%和78%,P<0.05。在绝对剂量体积比较中,3D-CRT的V60～V75及V45～V60均大于IMRT,V20～V45小于IMRT,差异均无统计学意义,P>0.05。结论:IMRT计划在早期NSCLC行SBRT治疗中不具有明显的剂量学优势。考虑到IMRT实施过程的复杂性和不确定性,早期NSCLC行SBRT治疗时3D-CRT可作为首选。     

The Long and the Short of it: the Role of Short-course Radiotherapy in the Neoadjuvant Management of Rectal Cancer

Total mesorectal excision is the cornerstone of treatment for rectal cancer. Multiple randomised trials have shown a reduction in local recurrence rates with the addition of preoperative radiotherapy, either as a 1-week hypofractionated short-course (SCRT) or a conventionally fractionated long-course (LCRT) schedule with concurrent chemotherapy. There is also increasing interest in the addition of neoadjuvant chemotherapy to radiotherapy with the aim of improving disease-free survival. The relative use of SCRT and LCRT varies considerably across the world. This is reflected in, and is probably driven in part by, disparity between international guideline recommendations. In addition, different approaches to treatment may exist both between and within countries, with variation related to patient, disease and treatment centre and financial factors. In this review, we will specifically focus on the use of SCRT for the treatment of rectal cancer. We will discuss the literature base and current guidelines, highlighting the challenges and controversies in clinical application of this evidence. We will also discuss potential future applications of SCRT, including its role in optimisation and intensification of treatment for rectal cancer.     

A Randomised Phase II Clinical Trial Comparing the Deliverability and Acute Toxicity of Wide Tangent versus Volumetric Modulated Arc Therapy to the Breast and Internal Mammary Chain

AimsInclusion of the internal mammary chain in the radiotherapy target volume (IMC-RT) improves disease-free and overall survival in higher risk breast cancer patients, but increases radiation doses to heart and lungs. Dosimetric data show that either modified wide-tangential fields (WT) or volumetric modulated arc therapy (VMAT) together with [AQ1]voluntary deep inspiration breath hold (vDIBH) keep mean heart doses below 4 Gy in most patients. However, the impact on departmental resources has not yet been documented. This phase II clinical trial compared the time taken to deliver IMC-RT using either WT and vDIBH or VMAT and vDIBH, together with planning time, dosimetry, set-up reproducibility and toxicity.Materials and methodsLeft-sided breast cancer patients requiring IMC-RT were randomised to receive either WT(vDIBH) or VMAT radiotherapy. The primary outcome was treatment time, powered to detect a minimum difference of 75 min (5 min/fraction) between techniques. The population mean displacement, systematic error and random error for cone beam computed tomography chest wall matches in three directions of movement were calculated. Target volume and organ at risk doses were compared between groups. Side-effects, including skin (Radiation Therapy Oncology Group), lung and oesophageal toxicity (Common Terminology Criteria for Adverse Events v 4.03) rates, were compared between the groups over 3 months. Patient-reported outcome measures, including shoulder toxicity at baseline, 6 months and 1 year, were compared.ResultsTwenty-one patients were recruited from a single UK centre between February 2017 and January 2018. The mean (standard deviation) total treatment time per fraction for VMAT treatments was 13.2 min (1.7 min) compared with 28.1 min (3.3 min) for WT(vDIBH). There were no statistically significant differences in patient set-up errors in between groups. The average mean heart dose for WT(vDIBH) was 2.6 Gy compared with 3.4 Gy for VMAT(vDIBH) (P = 0.13). The mean ipsilateral lung V_17Gy was 32.8% in the WT(vDIBH) group versus 34.4% in the VMAT group (P = 0.2). The humeral head (mean dose 16.8 Gy versus 2.8 Gy), oesophagus (maximum dose 37.3 Gy versus 20.1 Gy) and thyroid (mean dose 22.0 Gy versus 11.2 Gy) all received a statistically significantly higher dose in the VMAT group. There were no statistically significant differences in skin, lung or oesophageal toxicity within 3 months of treatment. Patient-reported outcomes of shoulder toxicity, pain, fatigue, breathlessness and breast symptoms were similar between groups at 1 year.ConclusionVMAT(vDIBH) and WT(vDIBH) are feasible options for locoregional breast radiotherapy including the IMC. VMAT improves nodal coverage and delivers treatment more quickly, resulting in less breath holds for the patient. This is at the cost of increased dose to some non-target tissues. The latter does not appear to translate into increased toxicity in this small study.     

Radiothérapie adaptative : stratégies et bénéfices selon les localisations tumorales

Adaptive radiotherapy (ART) is a complexe image-guided radiotherapy modality that comprises multiple planning to account for anatomical variations occurring during irradiation. Schematically, two strategies of RTA can be distinguished and combined according to tumor locations. One or more replanning can be proposed to correct systematic variations such as tumor shrinkage. A library of treatment plans with day-to-day plan selection from cone-beam CT imaging can also be proposed to correct random variations such as uterine motion or bladder/rectum volume changes. Because of strong anatomical variations occurring during irradiation, RTA appears therefore particularly justified in head and neck, lung, bladder, cervical and rectum and pancreas tumors, and to a lesser extent for prostate tumors and other digestive tumors. For these tumor locations, ART provides a fairly clear dosimetric benefit but a clinical benefit not yet formally demonstrated. ART cannot be proposed in a routine practice but must be evaluated medico-economically in the context of prospective trials. A rigorous quality control must be associated.     

分次立体定向放射治疗颅内良性肿瘤疗效分析

目的：回顾性分析分次立体定向放射治疗31例颅内良性肿瘤的疗效及并发症。方法：采用单纯分次立体定向放射治疗，每次剂量2．5—5Gy，总量35—52．5Gy，等效常规分割剂量50～62．4Gy。结果：症状消失22例，症状缓解8例，总有效率96，8％(30／31)；病变消失8例，缩小2l例，无1例出现脑血管意外，亦无视神经、面神经、脑干损伤及放射性脑坏死发生，垂体瘤患者无1例激素水平低下。结论：分次立体定向放射治疗颅内良性病变安全有效。有利于降低并发症。     

原发性肝癌三维适形放疗114例疗效评价

观察三维适形放射治疗（three-dimensional conformal radiotherapy,3DCRT）原发性肝癌的临床疗效.对114 例原发性肝癌患者在CT 定位下以3～5 mm层厚连续扫描,静脉双期碘造影剂增强扫描,精确定位治疗靶区并制定3DCRT计划,使90%等剂量曲线包绕计划靶体积（planning target volume,PTV）.以Varian 2100C 直线加速器实施放疗计划照射剂量1.8～2 Gy/次,5次/周,总剂量50～66 Gy,总疗程5～7周.治疗后1个月33例部分缓解,3个月42例部分缓解,6个月53例部分缓解.1、2和3年生存率分别为52.6%、35.1%和 28.9%.初步研究结果提示,3DCRT是原发性肝癌的有效无创治疗手段.     

Image-Guided Radiotherapy for Pelvic Cancers: A Review of Current Evidence and Clinical Utilisation

The meticulous selection and utilisation of image-guided radiotherapy (IGRT) are essential for optimal radiotherapy treatment delivery when using highly conformal treatment techniques in pelvic radiotherapy. Pelvic IGRT has several general IGRT issues to consider (such as choice of match strategy, prioritisation between multiple treatment targets and margin estimates) as well as issues specific to pelvic radiotherapy, in particular large inter-fraction organ variation. A range of interventions, including adaptive treatment strategies, have been developed to address these challenges. This review covers general considerations for the clinical implementation of pelvic IGRT in routine practice and provides an overview of current knowledge regarding pelvic inter-fraction organ motion. Published IGRT evidence for each of the major tumour sites (gynaecological, prostate, bladder, rectal and anal cancer) is summarised, as are state-of-the-art adaptive approaches. General recommendations for the implementation of an institutional pelvic IGRT strategy include.•Ensuring consistency between treatment intent and the IGRT approach utilised.•Ensuring minimum national and international IGRT guidance is followed while considering the benefit of daily volumetric IGRT.•Ensuring the appropriate allied health professionals (namely therapy radiographers/radiation therapists) lead on undertaking IGRT.•Ensuring the IGRT workflow procedure is clear and includes an escalation process for difficult set-ups.•Ensuring a robust IGRT service is in place before implementing advanced adaptive approaches.     

直肠癌术后放疗（附45例分析）

放疗在直肠癌的综合治疗中占有重要地位,特别是术后预防照射能够起到减少复发提高生存率的作用.本文收集1970年2月至1989年12月治疗的45例直肠癌术后病例:术后预防照射25例和术后复发治疗的20例.两组病例的临床所见和病理检查结果大致相同,前者5年生存率为37%(7/19),后者仅有2例活过3年,可见术后预防照射的预后明显优于复发放疗者.所以对病期偏晚的直肠癌应做预防放疗,可望改善本病的预后.     

直肠癌手术前后辅助放疗疗效比较

［目的］探讨比较术前单次、术前４０Ｇｙ放疗及术后放疗对直肠癌疗效的影响。〔方法）１２７例病理证实的直肠癌患者, 于１９９０年 ４月至 １９９４年 １２月随机分为 ３组,分别为术前单次组 ３９例,术前４０Ｇｙ组 ４３例和术后放疗组 ４５例。术前放疗组中病理 若属Ｔ_３期以上,则加用术后放疗。术前单次组放疗剂量为５Ｇｙ－６Ｇｙ／次,放疗后４８ 小时内手术。术前４０Ｇｙ组中位剂量为４０Ｇｙ／２０ 次（２０Ｇｙ－ ４０Ｇｙ）,放疗后休息 ４周手术。术后放疗组中位剂量为 ５５．１Ｇ ｙ／２９次（３０Ｇｙ－ ６３Ｇｙ／１５次～ ３５次）,手术放疗间隔为 ３～ ４ 周。［结果］全部病例中位随访７８个月,３组中位生存期分别为５５、５８、４７个月,Ｋａｐｌａｎ Ｍｅｉｅｒ法计算３年及５年生存率分别为 ７４．３％、４８７％,６７．４％、４８９％和６２２％、４２２％。局部复发率分别为１２．８％、２３．１％,１４．０％、２３．３％和２２．２％、２８．９％。单因素Ｌｏｇ ｒａｎｋ检验术前放疗２组３年局部复发率低于术后放疗（Ｐ＜０．０５）。５年局部复发率和生存率无差别。［结论］适当剂量的术前放 疗较术后放疗具有更高的局控率和较低的副反应。     

ADAC逆向调强放射治疗计划的验证

目的验证ADAC逆向调强治疗计划系统的物理精度.方法用胶片和电离室,检测IMRT 的MLC形状、空间点的绝对吸收剂量和等剂量曲线.结果IMRT的 MLC形状符合度误差1 mm,空间点绝对吸收剂量与计划计算的误差3.6%,等剂量曲线分布的胶片测量结果与计划计算的很接近.结论ADAC逆向治疗计划系统符合临床要求.     

局部进展期胃癌术后调强放疗的剂量学研究

目的:通过比较局部进展期胃癌术后调强放疗(IMRT)与三维适形放疗(3D-CRT)计划,评价IMRT与3D-CRT靶区与危及器官剂量分布的优劣。方法:对29例D2手术后完全切除的局部进展期胃癌病例同时作IMRT和3D-CRT计划,处方剂量45 Gy,依据DVH和等剂量曲线评价上述两种治疗计划。结果:与3D-CRT相比,IMRT靶区剂量适形性更好,平均剂量更高(均为P<0.001);IMRT靶区剂量均匀性亦更好(P<0.05)。肝脏平均剂量V5、V20均明显降低(分别为P<0.001及P<0.05);左肾平均剂量、V12、V22.5亦显著减低(均为P<0.001);而右肾平均剂量、V12、V22.5及脊髓最高剂量两者相比差异均无统计学意义。结论:局部进展期胃癌术后患者,IMRT比3D-CRT靶区剂量分布更好,同时能使肝脏和左肾得到更好的保护。     

我国食管癌放射治疗进展

食管癌是我国常见的恶性肿瘤之一,早期诊断滞后,确诊时80%的病例局部病灶已很广泛或远处转移。放射治疗是食管癌治疗最主要手段之一。本文介绍近年来我国在食管癌放射治疗和多学科综合治疗方面进展,包括单纯放射治疗、放疗与手术、放疗与化疗、放疗与腔内热疗综合治疗的进展。