Smet Stéphanie, Lambrecht Maarten, Vanstraelen Bianca, Nuyts Sandra
Department of Radiation Oncology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium,
Strahlenther Onkol. 2015 Jan;191(1):43-50. doi: 10.1007/s00066-014-0742-x. Epub 2014 Aug 29.
Several planning studies have already proven the substantial dosimetric advantages of RapidArc (RA) over standard intensity-modulated radiotherapy. We retrospectively compared RapidArc and standard sliding window IMRT (swIMRT) in locally advanced head and neck cancer, looking both at dosimetrics as well as toxicity and outcome.
CT datasets of 78 patients treated with swIMRT and 79 patients treated with RA were included. To compare the resulting dose distributions, the dose-volume parameters were evaluated for the planning target volumes (PTVs), clinical target volumes (CTVs), and organs at risk (OARs), and the number of MU were calculated. Acute toxicity was assessed by the Common Toxicity Criteria version 3.0.
PTV coverage with the 95% isodose was slightly better for RA. Dose distribution has proven to be significantly more homogenous with RA and led to a reduction of 62% in MU with better OAR sparing. As for toxicity, more grade 3 mucositis and dysphagia was observed for swIMRT, though we observed more grade 3 dermatitis for RA.
In our retrospective analysis, RA had better target coverage and better sparing of the OAR. Overall, the grade of acute toxicity was lower for RA than for swIMRT for the same types of tumor locations, except for the grade of dermatitis.
多项规划研究已证实，容积旋转调强放疗（RA）相对于标准调强放疗具有显著的剂量学优势。我们对局部晚期头颈癌患者的容积旋转调强放疗和标准滑动窗口调强放疗（swIMRT）进行了回顾性比较，同时考察了剂量学、毒性反应及治疗结果。
纳入78例接受标准滑动窗口调强放疗患者及79例接受容积旋转调强放疗患者的CT数据集。为比较所得剂量分布，对计划靶区（PTV）、临床靶区（CTV）及危及器官（OAR）的剂量体积参数进行评估，并计算机器跳数（MU）。采用3.0版常见毒性标准评估急性毒性反应。
容积旋转调强放疗在9５％等剂量线对计划靶区的覆盖略优。容积旋转调强放疗的剂量分布明显更均匀，机器跳数减少62％，对危及器官的保护更好。在毒性反应方面，标准滑动窗口调强放疗出现更多3级黏膜炎和吞咽困难，而容积旋转调强放疗出现更多3级皮炎。
在我们的回顾性分析中，容积旋转调强放疗对靶区的覆盖更好，对危及器官的保护更佳。总体而言，除皮炎分级外，对于相同肿瘤部位，容积旋转调强放疗的急性毒性反应等级低于标准滑动窗口调强放疗。
