Volumetric modulated arc therapy

体积调制电弧疗法
  • 文章类型: Journal Article
    背景:局部晚期直肠癌(LARC)的标准治疗包括新辅助放化疗,然后全直肠系膜切除术。文献中的不同数据显示,使用放疗剂量递增对肿瘤降低分期和病理完全缓解(pCR)率有益,然而,缺乏使用LARC创新技术(T3-4或N1-2)的剂量递增研究。
    目的:分析使用创新的放疗技术对LARC新辅助放疗剂量递增的作用。
    方法:2020年12月,我们对以下电子数据库进行了全面的文献检索:PubMed,WebofScience,Scopus和Cochrane图书馆。研究的限制期包括2009年1月至2020年12月发表的文章。通过标题和摘要进行筛选,以确定仅使用辐射剂量等效剂量2Gy分数(EQD2)≥54Gy和体积调制电弧疗法(VMAT)的研究,调强放射治疗或图像引导放射治疗(IGRT)技术。作者搜索总共产生了2287个结果,根据PRISMA集团(2009)的筛选过程,21种出版物符合选择标准,并被纳入审查。
    结果:使用的主要放射治疗技术包括VMAT和IGRT模式。主要剂量处方为55Gy至高风险体积,45Gy作为预防体积,在25个部分中使用同时集成增强技术(42.85%)。平均pCR为28.2%,处方剂量与缓解率之间无相关性(P值≥0.5)。R0边缘和括约肌保存率分别为98.88%和76.03%,分别。经过35个月的平均随访,局部控制为92.29%。G3或更高的毒性为11.06%,剂量处方和毒性之间没有相关性。与其他组相比,接受EQD2剂量>58.9Gy和BED>70.7Gy的患者手术并发症发生率更高(P值=0.047)。
    结论:使用创新技术的剂量递增新辅助放疗对于实现较高pCR率的LARC是安全的。EQD2剂量>58.9Gy与较高的手术并发症发生率相关。
    BACKGROUND: The standard treatment of locally advanced rectal cancers (LARC) consists on neoadjuvant chemoradiotherapy followed by total mesorectal excision. Different data in literature showed a benefit on tumor downstaging and pathological complete response (pCR) rate using radiotherapy dose escalation, however there is shortage of studies regarding dose escalation using the innovative techniques for LARC (T3-4 or N1-2).
    OBJECTIVE: To analyze the role of neoadjuvant radiotherapy dose escalation for LARC using innovative radiotherapy techniques.
    METHODS: In December 2020, we conducted a comprehensive literature search of the following electronic databases: PubMed, Web of Science, Scopus and Cochrane library. The limit period of research included articles published from January 2009 to December 2020. Screening by title and abstract was carried out to identify only studies using radiation doses equivalent dose 2 Gy fraction (EQD2) ≥ 54 Gy and Volumetric Modulated Arc Therapy (VMAT), intensity-modulated radiotherapy or image-guided radiotherapy (IGRT) techniques. The authors\' searches generated a total of 2287 results and, according to PRISMA Group (2009) screening process, 21 publications fulfil selection criteria and were included for the review.
    RESULTS: The main radiotherapy technique used consisted in VMAT and IGRT modality. The mainly dose prescription was 55 Gy to high risk volume and 45 Gy as prophylactic volume in 25 fractions given with simultaneous integrated boosts technique (42.85%). The mean pCR was 28.2% with no correlation between dose prescribed and response rates (P value ≥ 0.5). The R0 margins and sphincter preservation rates were 98.88% and 76.03%, respectively. After a mean follow-up of 35 months local control was 92.29%. G3 or higher toxicity was 11.06% with no correlation between dose prescription and toxicities. Patients receiving EQD2 dose > 58.9 Gy and BED > 70.7 Gy had higher surgical complications rates compared to other group (P value = 0.047).
    CONCLUSIONS: Dose escalation neoadjuvant radiotherapy using innovative techniques is safe for LARC achieving higher rates of pCR. EQD2 doses > 58.9 Gy is associated with higher rate of surgical complications.
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  • 文章类型: Case Reports
    恶性阴茎异常勃起是由肿瘤转移浸润继发的疼痛性硬结和阴茎勃起的病症。这种情况与不良预后有关。我们报道了一个87岁的男人,在诊断为转移性Gleason4+5前列腺癌后,阴茎部分竖立。磁共振成像(MRI)显示他的海绵体弥漫性双侧浸润。阴茎结节的核心活检显示它是与前列腺起源一致的低分化癌。大剂量姑息适形放疗(16分40Gy)治疗后,患者症状完全缓解。我们系统地审查了姑息性放疗治疗恶性阴茎异常勃起的临床报告,目的是获得有关这种罕见疾病治疗的更多信息。
    Malignant priapism is a condition of painful induration and erection of the penis secondary to metastatic infiltration by a neoplasm. This condition is associated with a poor prognosis. We report on a case of an 87-year-old man who presented with a painful, partially erected penis subsequent to a diagnosis of metastatic Gleason 4+5 prostate cancer. Magnetic resonance imaging (MRI) showed diffuse bilateral infiltration of his corpora cavernosa. The core biopsy of the penile nodule revealed it to be a poorly differentiated carcinoma consistent with prostatic origin. The patient\'s symptoms were completely resolved after treatment with high-dose palliative conformal radiotherapy (40Gy in 16 fractions). We systemically reviewed clinical reports of palliative radiotherapy for malignant priapism with the aim to gain more information on the management of this rare condition.
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  • 文章类型: Journal Article
    Despite the introduction of new radiotherapy techniques, such as intensity modulated radiation therapy or stereotactic body radiation therapy, radiation induced lung injury remains a significant treatment related adverse event of thoracic radiation therapy. Functional lung avoidance radiation therapy is an emerging concept in the treatment of lung disease to better preserve lung function and to reduce pulmonary toxicity. While conventional ventilation/perfusion (V/Q) lung scintigraphy is limited by a relatively low spatial and temporal resolution, the recent advent of 68Gallium V/Q lung PET/CT imaging offers a potential to increase the accuracy of lung functional mapping and to better tailor lung radiation therapy plans to the individual\'s lung function. Lung PET/CT imaging may also improve our understanding of radiation induced lung injury compared to the current anatomical based dose-volume constraints. In this review, recent advances in radiation therapy for the management of primary and secondary lung tumors and in V/Q PET/CT imaging for the assessment of functional lung volumes are reviewed. The new opportunities and challenges arising from the integration of V/Q PET/CT imaging in radiation therapy planning are also discussed.
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  • 文章类型: Journal Article
    脊索瘤是生长缓慢的侵袭性肿瘤,占所有骨肿瘤的1-4%。脊索瘤的解剖分布包括骶尾部区域的50-60%,25-30%的颅底和15%的移动脊柱。Virchow于1857年第一个将这些肿瘤描述和命名为“湿疹physaliophora”,Muller于1895年建立了它们的脊索起源。鼻咽骨外脊索瘤非常罕见,它们与鼻咽部的其他病变相似,表现为软组织肿块。大体全切除结合术后放疗提供了长期控制的最佳机会。我们在此介绍了一名63岁的女性患者,患有左颞叶头痛,头晕,左鼻塞,左上颌区麻木,左耳听力损失和吞咽困难。计算机断层扫描检查显示鼻咽和口咽部有8.2x3.2x5.7cm占位性病变伴中央坏死,部分阻塞咽腔;肿块浸润左侧咽旁间隙,左内侧和外侧翼状肌和左腮腺,左下颌骨骨侵蚀。病人被诊断为鼻咽骨外脊索瘤,传统型,阶段IIB。患者接受了手术和大剂量放疗,并实现了脊索瘤的局部控制。然而,病人死于肺转移.案件的细节进行了讨论,并对当前的医学文献进行了综述,以提供有关鼻咽脊索瘤研究现状的最新讨论。
    Chordomas are slow-growing aggressive tumors that account for 1-4% of all bone tumors. The anatomical distribution of chordomas includes 50-60% in the sacrococcygeal region, 25-30% in the skull base and 15% in the mobile spine. Virchow was the first to describe and term these tumors as \'ecchordosis physaliphora\' in 1857, and Muller established their notochordal origin in 1895. Extraosseous chordomas of the nasopharynx are very rare, and they exhibit similarities with other lesions of the nasopharynx, presenting as a soft tissue mass. Gross total resection combined with postoperative radiotherapy offers the best chance of long-term control. We herein present the case of a 63-year-old female patient with complaints of left temporal headaches, dizziness, left nasal obstruction, left maxillary area numbness, left ear hearing loss and swallowing difficulty. Computed tomography imaging examination revealed an 8.2x3.2x5.7-cm space-occupying lesion with central necrosis in the nasopharynx and oropharynx, partially occluding the pharyngeal lumen; the mass had infiltrated the left parapharyngeal space, the left medial and lateral pterygoid muscle and the left parotid gland, with bone erosion of the left mandible. The patient was diagnosed with extraosseous chordoma of the nasopharynx, conventional type, stage IIB. The patient underwent surgery and high-dose radiotherapy and local control of the chordoma was achieved. However, the patient succumbed to a lung metastasis. The details of the case are discussed, and a review of the current medical literature is presented to provide an updated discussion on the current status of nasopharyngeal chordoma research.
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  • 文章类型: Journal Article
    OBJECTIVE: Fixed-field intensity modulated radiation therapy (FF-IMRT) or volumetric modulated arc therapy (VMAT) beams complexity is due to fluence fluctuation. Pre-treatment Quality Assurance (PTQA) failure could be linked to it. Several plan complexity metrics (PCM) have been published to quantify this complexity but in a heterogeneous formalism. This review proposes to gather different PCM and to discuss their eventual PTQA failure identifier abilities.
    METHODS: A systematic literature search and outcome extraction from MEDLINE/PubMed (National Center for Biotechnology Information, NCBI) was performed. First, a list and a synthesis of available PCM is made in a homogeneous formalism. Second, main results relying on the link between PCM and PTQA results but also on other uses are listed.
    RESULTS: A total of 163 studies were identified and n = 19 were selected after inclusion and exclusion criteria application. Difference is made between fluence and degree of freedom (DOF)-based PCM. Results about the PCM potential as PTQA failure identifier are described and synthesized. Others uses are also found in quality, big data, machine learning and audit procedure.
    CONCLUSIONS: A state of the art is made thanks to this homogeneous PCM classification. For now, PCM should be seen as a planning procedure quality indicator although PTQA failure identifier results are mitigated. However limited clinical use seems possible for some cases. Yet, addressing the general PTQA failure prediction case could be possible with the big data or machine learning help.
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  • 文章类型: Case Reports
    UNASSIGNED: To evaluate the dose sparing efficacy of intraoral customized stents in combination with IGRT/VMAT in Head & Neck cancer patients.
    UNASSIGNED: Despite advances in high-dose conformal radiotherapy (RT) techniques, adverse effects (such as oral mucositis) during and after RT often require temporary suspension of treatment and affect the quality of life in survivors. Intraoral customized stents can decrease radiation doses in healthy tissues and minimize damage from radiations. At the best of our knowledge the clinical impact of such devices in combination with VMAT (volumetric modulated arc therapy) is not reported in the literature.
    UNASSIGNED: Three Head & Neck cancer patients were submitted to image guided (IG) RT/VMAT in their treatment protocol. Dose distribution with and without the use of an intraoral stent was compared in each patient. Mean radiation doses proved to be lower in all patients, especially in the subsite: oral cavity.
    UNASSIGNED: There are several reports on the efficacy of IS during RT for Head & Neck cancer. Despite technological advances, the combination between high conformal RT and intraoral stents could still play a role in the management of this kind of patients. This strengthens the usefulness of the individualization of treatments and multidisciplinary approach.
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  • 文章类型: Review
    BACKGROUND: Radiotherapy management of patients with brain metastases most commonly involve a whole-brain radiation therapy (WBRT) regime, as well as newer techniques such as stereotactic radiosurgery (SRS) and intensity modulated radiotherapy (IMRT). The long treatment times incurred by these techniques indicates the need for a novel technique that has shorter treatment times, whilst still producing highly conformal treatment with the potential to deliver escalated doses to the target area. Volumetric modulated arc therapy (VMAT) is a dynamic, highly conformal technique that may deliver high doses of radiation through a single gantry arc and reduce overall treatment times. The aim of this systematic review is to determine the feasibility and benefits of VMAT treatment in regard to overall survival rates and local control in patients with brain metastases, in comparison with patients treated with WBRT, SRS and IMRT.
    METHODS: A search of the literature identified 23 articles for the purpose of this review. Articles were included on the basis they were human-based studies, with sample sizes of more than five patients who were receiving treatment for 1-10 metastatic brain lesions.
    RESULTS: VMAT was found to be highly conformal, have a reduced treatment delivery time and incurred no significant toxicities in comparison with WBRT, SRS and IMRT.
    CONCLUSIONS: Compared to other treatment techniques, VMAT proved to have fewer toxicities than conventional WBRT, shorter treatment times than SRS and similar dose distributions to IMRT plans. Future prospective studies are needed to accurately assess the prognostic benefits of VMAT as well as the occurrence of late toxicities.
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    文章类型: Case Reports
    目的:在本文中,我们回顾了体积调制电弧疗法(VMAT)对位于纵隔结构中央的小肺结节的应用。
    方法:一名无法手术的患者,临床IA期右肺腺癌在15个派别中接受了52.5Gy的外束放射治疗。使用单个360°共面弧VMAT计划(360-VMAT)进行治疗,并与步进射击强度调制放射疗法(IMRT)和单个180°同侧部分弧VMAT计划(180-VMAT)进行比较。
    结果:规划目标量(PTV)覆盖范围没有差异,360-VMAT的剂量均匀性最高。与IMRT相比,360-VMAT和180-VMAT均降低了食道剂量。虽然IMRT的肺剂量最低,所有3个计划均实现了可接受的肺保留。180-VMAT具有最高的剂量一致性。与IMRT相比,360-VMAT和180-VMAT均改善了食管保留。
    结论:在早期阶段使用VMAT,位于中央的NSCLC是一种有希望的治疗方法,值得进一步研究.
    OBJECTIVE: In the present article we review on the use of Volumetric Modulated Arc Therapy (VMAT) for a small lung nodule that was centrally located in close proximity to the mediastinal structures.
    METHODS: An inoperable patient with central, clinical stage IA adenocarcinoma of the right lung was treated with external-beam radiation therapy of 52.5 Gy in 15 factions. A single 360° coplanar arc VMAT plan (360-VMAT) was used for treatment and compared to step-and-shoot Intensity Modulation Radiotherapy (IMRT) and a single 180° ipsilateral partial arc VMAT plan (180-VMAT).
    RESULTS: Planning Target Volume (PTV) coverage was not different, and 360-VMAT had the highest dose homogeneity. Both 360-VMAT and 180-VMAT reduced esophageal dose compared to IMRT. While IMRT had the lowest lung dose, all 3 plans achieved acceptable sparing of the lung. 180-VMAT had the highest dose conformity. Both 360-VMAT and 180-VMAT improved esophageal sparing compared to IMRT.
    CONCLUSIONS: Use of VMAT in early-stage, centrally located NSCLC is a promising treatment approach and merits additional investigation.
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