图像引导放射治疗的临床应用

图像引导放射治疗(IGRT)是继三维适形放疗(3DCRT)和调强适形放疗(IMRT)之后,又一新的放疗技术,是提高放射治疗精度、保证与控制放疗质量的重要手段.这一技术发展快,普及快,有很强的治疗优势.     

利用锥形束CT图像分析非小细胞肺癌临床靶区外放的研究

目的 探讨非小细胞肺癌三维适形放射治疗临床靶区的外放范围。方法 8例非小细胞肺癌患者均采用三维适形放疗或调强放疗。分次放疗前、后患者在治疗床上进行锥形束CT扫描,并将锥形束CT图像与计划CT图像进行在线配准,根据配准得到的平移矢量调整治疗床的位置,从而修正摆位误差,并分别记录各个方向上平移矢量。结果 8例患者共计160组配准数据。如果放射治疗过程中未进行在线图像引导校正,在实际应用中临床靶区外放10.9 mm;如果每次放射治疗均进行在线图像引导校正,在实际应用中临床靶区外放2.2 mm。结论 非小细胞肺癌三维适形调强放疗时具有一定的摆位误差。基于锥形束CT图像分析的在线校正方法能减小该摆位误差,并有助于确定合适的临床靶区外放。     

非小细胞肺癌精确放疗技术的进展

放射治疗已经进入精确治疗时代,即＂精确定位、精确计划、精确治疗＂,从病人的定位至靶区的勾画、计划的设计以及治疗过程的实施,每一个环节都在努力减少各种因素所致的误差,目的 是提高局部肿瘤剂量,减少正常组织的并发症.近二十年,放射治疗技术发展迅速,已从三维适形放疗、调强放射治疗发展到图像引导放疗、容积弧形调强放射治疗,本文重点介绍以上技术在非小细胞肺癌中的临床应用及疗效,以及早期NSCLC放射治疗的相关研究.     

食管癌放射治疗技术的选择与应用

放射治疗是食管癌的根治性手段之一。随着医学影像学、计算机技术及放射物理学的快速发展,放疗技术取得了革命性的进步,从常规放疗迈进精确放疗时代。现综述放射治疗技术在食管癌放疗中的选择和应用,主要包括常规放射治疗、 X刀、γ刀、三维适形放疗、调强适形放疗、图像引导调强放疗、容积弧形调强放射治疗、自适应放疗及内照射后装治疗等。     

肺癌在线自适应放射治疗中国专家共识

摘 要：肺癌是我国发病率和死亡率最高的恶性肿瘤。精准放疗显著提高了肿瘤控制率、降低了不良反应,其中在图像引导放疗基础上发展起来的在线自适应放射治疗可以根据实时影像反馈动态调整放疗区域和剂量,已逐步应用于肺癌治疗。为规范临床应用、推动技术发展与临床协作,特制定本专家共识。该共识结合理论与实践,阐述肺癌在线自适应放射治疗的物理技术要求、临床实施规范和常见临床问题,以期更好地为放疗同道了解和开展该技术提供参考,使更多肺癌患者能从放射治疗中获益。     

多模医学图像引导的非小细胞肺癌放疗研究新进展

放射治疗是目前非小细胞肺癌的主要治疗手段之一,在放疗过程中,利用功能影像与CT解剖影像相结合,不但提高了肿瘤靶区的勾画精度,而且,还能利用功能影像显示的靶区细胞的生物学特性,进行生物功能图像引导的剂量雕刻（dose painting）治疗,这是放射治疗发展过程的一个重要转折点.对局部晚期非小细胞肺癌而言,采用累及野照射的方式优于选择性淋巴结照射.利用4D-CT图像引导的个体化靶区勾画、锥形束CT（cone beam CT,CBCT）图像引导放疗和自适应放疗（adaptive radiation therapy,ART）技术的应用,进一步提高了非小细胞肺癌放疗的精度,可望减少放射性肺炎等正常组织损伤、提高肿瘤控制率和改善疗后生存质量.     

影像学技术在图像引导宫颈癌近距离放射治疗中的应用

图像引导放射治疗是一种很有前途的放射治疗技术,可以提高宫颈癌患者的局部控制率,降低并发症发生率。MRI软组织分辨率高,是图像引导宫颈癌近距离放射治疗公认的金标准。CT软组织分辨率虽不及MRI,但更易识别施源器、源和源路径,在宫颈癌的放疗计划中,CT的使用率远远高于MRI。新的成像技术,如PET和MRI,改善了放疗计划中靶区的勾画,特别是PET联合CT、MRI,在功能成像方面也显得越来越重要。在病人初始分期方面,超声已经被MRI取代,但在图像引导妇科插植和腔内近距离治疗中起重要作用。本综述的目的是评估各种影像技术在图像引导宫颈癌近距离放射治疗中的应用。     

18F-FDGPET-CT用于胰腺癌放疗的研究进展

胰腺恶性肿瘤的治疗是消化系统恶性肿瘤治疗的一个难点,结合各种治疗手段的现状,目前胰腺癌治疗的观念及模式需进一步转变。然而随着现代放射治疗技术图像引导放射治疗（IGRT）等精确放疗技术在胰腺癌治疗中的广泛引用,胰腺癌患者得到了明显生存获益。先进的影像学设备为精确放疗技术提供了重要的基础,本文主要围绕18F-PDG PET-CT 检查在胰腺癌放射治疗中各方面的临床价值进行综述。     

鼻咽癌精确放疗的研究进展

鼻咽癌是我国最常见的恶性肿瘤之一, 全世界80%的鼻咽癌发生在我国。放射治疗是鼻咽癌首选治疗手段, 现代的放射治疗技术已从常规放疗发展至精确放疗, 从三维适形放射治疗至适形调强放射治疗再到图像引导放射治疗的出现, 不但提高了放疗的准确性, 而且大大减轻了放疗的副反应, 逐渐成为现代放疗的主流技术。本文主要介绍了以上技术在鼻咽癌治疗中的应用、疗效及国内外的研究现状。     

实现图像引导放射治疗的设备保证

图像引导放射治疗的发展(Image-guided radiation therapy,IGRT)是以图像引导设备的发展为基础的.随着放射物理学、医学影像学及计算机科学的快速发展,IGRT必将开创精确放疗的新时代.本文将对IGRT的设备和技术进行论述,并展望未来发展趋势.     

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.     

影像引导放射治疗系统

影像引导放射治疗(IGRT)是近年来放射肿瘤学领域最先进的治疗技术。通过新型IGRT系统,将影像获取、治疗计划设计、CT模拟定位及加速器治疗完美地整合到一套放疗系统之中,以精确实施放射治疗。目前IGRT设备主要有传统直线加速器结合影像系统、断层放射治疗机和影像引导的立体定向治疗机。现就该类新技术及其临床应用作一综述。     

From IMRT to IGRT: frontierland or neverland?

The recent enthusiasm for real-time image guidance in radiotherapy (IGRT) is in part due to the commercial availability of advanced on-line imaging technologies. Perhaps more important than its potential to improve conventional radiotherapy, IGRT may lead to a paradigm shift in facilitating hypo-fractionated or single-dose treatment. However, there are uncertainty regarding features and approaches of competing IGRT systems and as to whether a sub-set of the features of an ideal IGRT system would suffice for specific disease sites and clinical applications. Clinical studies are necessary for the quantification of benefit needed for evidence-based medicine.     

Faculty of Radiation Oncology Position Paper on the use of Image–Guided Radiation Therapy

The development of technology such as intensity‐modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and stereotactic ablative body radiotherapy (SABR) has resulted in highly conformal radiotherapy treatments. While such technology has allowed for improved dose delivery, it has also meant that improved accuracy in the treatment room is required. Image‐guided radiotherapy (IGRT), the use of imaging prior to or during treatment delivery, has been shown to improve the accuracy of treatment delivery and in some circumstances, clinical outcomes. Allied with the adoption of highly conformal treatments, there is a need for stringent quality assurance processes in a multidisciplinary environment. In 2015, the Royal Australian and New Zealand College of Radiologist (RANZCR) updated its position paper on IGRT. The draft document was distributed through the membership of the Faculty of Radiation Oncology (FRO) for review and the final version was endorsed by the board of FRO. This article describes issues that radiotherapy departments throughout Australia and New Zealand should consider. It outlines the role of IGRT and reviews current clinical evidence supporting the benefit of IGRT in genitourinary, head and neck, and lung cancers. It also highlights important international publications which provide guidance on implementation and quality assurances for IGRT. A set of key recommendations are provided to guide safe and effective IGRT implementation and practice in the Australian and New Zealander context.     

Image-guided radiotherapy: has it influenced patient outcomes?

Cancer control and toxicity outcomes are the mainstay of evidence-based medicine in radiation oncology. However, radiotherapy is an intricate therapy involving numerous processes that need to be executed appropriately in order for the therapy to be delivered successfully. The use of image-guided radiation therapy (IGRT), referring to imaging occurring in the radiation therapy room with per-patient adjustments, can increase the agreement between the planned and the actual dose delivered. However, the absence of direct evidence regarding the clinical benefit of IGRT has been a criticism. Here, we dissect the role of IGRT in the radiotherapy (RT) process and emphasize its role in improving the quality of the intervention. The literature is reviewed to collect evidence that supports that higher-quality dose delivery enabled by IGRT results in higher clinical control rates, reduced toxicity, and new treatment options for patients that previously were without viable options.     

Radiothérapie guidée par l’image des cancers prostatiques : concepts et implications

Intensity modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT) are technological developments, which when applied in a model of prostate cancer, led to a significant reduction in the toxicity and digestive and urinary sequelae of 3D conformational radiotherapy. The major clinical benefits of these techniques with regard to reduced digestive and urinary toxicity are unequivocal since very few sequelae have been reported at 10 years (2% of grade 2 and 1% of grade 3 digestive toxicity; 11% of grade 2 and 5% of grade 3 urinary toxicity). Even when these two techniques are combined, IG–IMRT significantly diminishes late genitourinary toxicity. In the absence of adaptive radiotherapy, there are many IGRT protocols and repositioning techniques, and every step in the IGRT process must be carried out with extreme rigor: installing the patient and contention system, repositioning technique with or without fiduciary markers, type of repositioning imaging, definition of margins inherent in each technique (prostate, seminal vesicles and/or pelvic lymph nodes), frequency of repositioning during treatment, dietary constraints with or without rectal lavage. For these reasons, every centre that performs IGRT must carefully and rigorously assess the uncertainties of repositioning linked to the IGRT technique. In this review, we analyzed data from the literature based on dosimetric studies and the proven clinical impact in order to answer the different questions asked by radiation oncologists at every step of the IGRT process for cancer of the prostate. Recommendations are made for the repositioning protocols according to the most widely used repositioning techniques: fiduciary markers or soft tissues, kV-CBCT or MV-CBCT, 3D ultrasonography.     

Image-guided Adaptive Radiotherapy for Bladder Cancer

Technological advancement has facilitated patient-specific radiotherapy in bladder cancer. This has been made possible by developments in image-guided radiotherapy (IGRT). Particularly transformative has been the integration of volumetric imaging into the workflow. The ability to visualise the bladder target using cone beam computed tomography and magnetic resonance imaging initially assisted with determining the magnitude of inter- and intra-fraction target change. It has led to greater confidence in ascertaining true anatomy at each fraction. The increased certainty of dose delivered to the bladder has permitted the safe reduction of planning target volume margins. IGRT has therefore improved target coverage with a reduction in integral dose to the surrounding tissue. Use of IGRT to feed back into plan and dose delivery optimisation according to the anatomy of the day has enabled adaptive radiotherapy bladder solutions. Here we undertake a review of the stepwise developments underpinning IGRT and adaptive radiotherapy strategies for external beam bladder cancer radiotherapy. We present the evidence in accordance with the framework for systematic clinical evaluation of technical innovations in radiation oncology (R-IDEAL).     

The Pivotal Role of the Therapeutic Radiographer/Radiation Therapist in Image-guided Radiotherapy Research and Development

The ability to personalise radiotherapy to fit the individual patient and their diagnosis has been realised through technological advancements. There is now more opportunity to utilise these technologies and deliver precision radiotherapy for more patients. Image-guided radiotherapy (IGRT) has enabled users to safely and accurately plan, treat and verify complex cases; and deliver a high dose to the target volume, while minimising dose to normal tissue. Rapid changes in IGRT have required a multidisciplinary team (MDT) approach, carefully deciding optimum protocols to achieve clinical benefit. Therapeutic radiographer/radiation therapists (RTTs) play a pivotal role in this MDT. There is already a great deal of evidence that illustrates the contribution of RTTs in IGRT development; implementation; quality assurance; and maintaining training and competency programmes. Often this has required the RTT to undertake additional roles and responsibilities. These publications show how the profession has evolved, expanding the scope of practice. There are now more opportunities for RTT-led IGRT research. This is not only undertaken in the more traditional aspects of practice, but in recent times, more RTTs are becoming involved in imaging biomarkers research and radiomic analysis. The aim of this overview is to describe the RTT contribution to the ongoing development of IGRT and to showcase some of the profession's involvement in IGRT research.     

La radiothérapie guidée par l’image (IGRT)

Image guided radiation therapy (IGRT) is a major technical innovation of radiotherapy. It allows locating the tumor under the linear accelerator just before the irradiation, by direct visualization (3D mode soft tissue) or indirect visualization (2D mode and radio-opaque markers). The technical implementation of IGRT is done by very different complex devices. The most common modality, because available in any new accelerator, is the cone beam CT. The main experiment of IGRT focuses on prostate cancer. Preliminary studies suggest the use of IGRT combined with IMRT should increase local control and decrease toxicity, especially rectal toxicity. In head and neck tumors, due to major deformation, a rigid registration is insufficient and replanning is necessary (adaptive radiotherapy). The onboard imaging delivers a specific dose, needed to be measured and taken into account, in order not to increase the risk of toxicity. Studies comparing different modalities of IGRT according to clinical and economic endpoints are ongoing; to better define the therapeutic indications.     

Effectiveness of intensity-modulated and image-guided radiotherapy to spare the mandible from excessive radiation

We would like to assess the effectiveness of intensity-modulated radiotherapy (IMRT) or image-guided radiotherapy (IGRT) to decrease the risk of osteoradionecrosis in locally advanced head and neck cancer. We conducted a retrospective study of 83 patients with head and neck cancer undergoing concurrent definitive chemoradiation, post-operative radiotherapy or chemoradiation, or radiotherapy alone with IMRT or IGRT. Mean mandibular dose was, respectively, 43.6Gy and 43.8Gy for the IMRT and IGRT technique. At a median follow-up of 28 months (5-55 months), only one patient developed osteoradionecrosis requiring hyperbaric oxygen. Sharp dose falloff associated with IMRT and IGRT decreased excessive radiation of the mandible and may reduce the risks of osteoradionecrosis.