Head and Neck Unit, Imperial College Healthcare NHS Trust, Fulham Palace Road, London W6 8RF, UK; Department of Surgery and Cancer, Imperial College, London, UK.
Head and Neck Unit, The Royal Marsden Hospital, 203 Fulham Road, London SW3 6JJ, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, 237 Fulham Road, London SW6 4NE, UK.
Oral Oncol. 2018 Nov;86:225-233. doi: 10.1016/j.oraloncology.2018.09.011. Epub 2018 Oct 4.
Intensity modulated radiotherapy (IMRT) in head and neck cancer allows sculpting of radiation dose to conform closely to target volumes and spare organs at risk. However, this may be offset by an increased risk of a geographical miss and reduction in survival outcomes. We reviewed the data from 5 prospective randomized controlled trials, one prospective phase II trial and 10 retrospective comparative series in terms of patterns of failure, treatment outcomes and late toxicities to determine any compromise in survival outcomes in favour of reduced late toxicity. Whilst there was some variablility in target volume delineation, radiation dose and technique, the published data consistently show reduced long term xerostomia (ranging from 0.5 to 87%) with IMRT compared to older radiation techniques. Some studies showed reduced incidence of >10% weight loss and grade ≥2 dysphagia with IMRT, and 2 studies reported higher rates of dysphagia with IMRT. Most studies demonstrated better, though non-significant, locoregional, disease-free and overall survival. The 4 studies that did demonstrate significantly better overall survival with IMRT were the largest cohorts with around 250 patients or greater. Standardization of target volume delineation, treatment verification protocols and outcome reporting will reduce heterogeneity and allow data to be pooled in order to be adequately powered for survival analyses.
调强放疗（IMRT）在头颈部肿瘤中可以使放射剂量精确地适形于靶区并保护危险器官。然而，这可能会导致局部控制率降低和生存结果的恶化。我们回顾了 5 项前瞻性随机对照试验、1 项前瞻性 II 期试验和 10 项回顾性比较系列的资料，以评估失败模式、治疗结果和晚期毒性，以确定在生存结果方面是否存在因降低晚期毒性而产生的妥协。尽管靶区勾画、放射剂量和技术存在一定的变异性，但已发表的资料一致显示，与传统放疗技术相比，IMRT 可显著降低长期口干症（0.5%至 87%）的发生率。一些研究显示，IMRT 可降低 10%以上体重减轻和 2 级以上吞咽困难的发生率，而 2 项研究则报告了 IMRT 后吞咽困难发生率更高。大多数研究显示，尽管无统计学意义，但局部区域无病生存率和总生存率有所改善。4 项显示 IMRT 可显著提高总体生存率的研究是规模最大的队列研究，每组患者超过 250 例。靶区勾画、治疗验证方案和结果报告的标准化将减少异质性，并允许对数据进行汇总，以便对生存分析进行充分的统计学检验。
