Speech Pathology Department, Prince of Wales Hospital (POWH), Randwick, Sydney, NSW, 2031, Australia.
School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, 4072, Australia.
Dysphagia. 2019 Dec;34(6):869-878. doi: 10.1007/s00455-019-09983-y. Epub 2019 Feb 11.
Recent evidence suggests that reducing radiotherapy dose delivered to specific anatomical swallowing structures [Swallowing Organs at Risk (SWOARs)] may improve swallowing outcomes post-treatment for patients with head and neck cancer. However, for those patients with tumours of the oropharynx, which typically directly overlap the SWOARs, reducing dose to these structures may be unachievable without compromising on the treatment of the disease. To assess the feasibility of dose reduction in this cohort, standard IMRT plans (ST-IMRT) and plans with reduced dose to the SWOARs (SW-IMRT) were generated for 25 oropharyngeal cancer patients (Brouwer et al. in Radiother Oncol 117(1):83-90, https://doi.org/10.1016/j.radonc.2015.07.041 , 2015; Christianen et al. in Radiother Oncol 101(3):394-402, https://doi.org/10.1016/j.radonc.2011.05.015 , 2011). ST-IMRT and SW-IMRT plans were compared for: mean dose to the SWOARs, volume of pharynx and larynx receiving 50 Gy and 60 Gy (V50 and V60 respectively) and overlap between the tumour volume and the SWOARs. Additionally, two different SWOARs delineation guidelines (Brouwer et al. in Radiother Oncol 117(1):83-90, https://doi.org/10.1016/j.radonc.2015.07.041 , 2015; Christianen et al. in Radiother Oncol 101(3):394-402, https://doi.org/10.1016/j.radonc.2011.05.015 , 2011) were used to highlight differences in calculated volumes between existing contouring guidelines. Agreement in SWOARs volumes between the two guidelines was calculated using a concordance index (CI). Despite a large overlap between the tumour and SWOARs, significant (p < 0.05) reductions in mean dose to 4 of the 5 SWOARs, and V50/V60 for the pharynx and larynx were achieved with SW-IMRT plans. Low CIs per structure (0.15-0.45) were found between the two guidelines highlighting issues comparing data between studies when different guidelines have been used (Hawkins et al. in Semin Radiat Oncol 28(1):46-52, https://doi.org/10.1016/j.semradonc.2017.08.002 , 2018; Brodin et al. in Int J Radiat Oncol Biol Phys 100(2):391-407, https://doi.org/10.1016/j.ijrobp.2017.09.041 , 2018). This study found reducing dose to the SWOARs is a feasible practice for patients with oropharyngeal cancer. However, future prospective research is needed to determine if the extent of dose reduction achieved equates to clinical benefits.
最近的证据表明，降低特定解剖结构（吞咽器官危险器官 [Swallowing Organs at Risk (SWOARs)]）的放疗剂量可能会改善头颈部癌症患者治疗后的吞咽功能。然而，对于那些患有口咽癌的患者，肿瘤通常直接与 SWOARs 重叠，因此如果不降低这些结构的剂量，就无法治疗肿瘤。为了评估在这一组患者中降低剂量的可行性，为 25 例口咽癌患者生成了标准调强放疗计划（ST-IMRT）和降低 SWOARs 剂量的计划（SW-IMRT）（Brouwer 等人，放射肿瘤学 117(1):83-90，https://doi.org/10.1016/j.radonc.2015.07.041，2015 年；Christianen 等人，放射肿瘤学 101(3):394-402，https://doi.org/10.1016/j.radonc.2011.05.015，2011 年）。对 ST-IMRT 和 SW-IMRT 计划进行了比较：SWOARs 的平均剂量、接受 50Gy 和 60Gy 的咽和喉的体积（分别为 V50 和 V60）以及肿瘤体积与 SWOARs 之间的重叠。此外，使用了两种不同的 SWOARs 勾画指南（Brouwer 等人，放射肿瘤学 117(1):83-90，https://doi.org/10.1016/j.radonc.2015.07.041，2015 年；Christianen 等人，放射肿瘤学 101(3):394-402，https://doi.org/10.1016/j.radonc.2011.05.015，2011 年）来突出现有勾画指南之间计算体积的差异。使用一致性指数（CI）计算了两个指南之间 SWOARs 体积的一致性。尽管肿瘤与 SWOARs 之间存在很大的重叠，但 SW-IMRT 计划显著（p<0.05）降低了 5 个 SWOARs 中的 4 个的平均剂量，以及咽和喉的 V50/V60。每个结构的低 CI（0.15-0.45）表明，当使用不同的指南时，比较研究之间的数据会出现问题（Hawkins 等人，放射肿瘤学 28(1):46-52，https://doi.org/10.1016/j.semradonc.2017.08.002，2018 年；Brodin 等人，国际放射肿瘤学杂志 100(2):391-407，https://doi.org/10.1016/j.ijrobp.2017.09.041，2018 年）。本研究发现，降低 SWOARs 的剂量对于口咽癌患者来说是一种可行的做法。然而，需要进一步的前瞻性研究来确定所实现的剂量降低程度是否等同于临床获益。
