Department of Oral Health Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, BC, Canada.
Provincial Practice Leader in Prosthodontics, Oral Oncology and Dentistry, BC Cancer, Vancouver, BC, Canada.
J Prosthodont. 2019 Jul;28(6):643-648. doi: 10.1111/jopr.13074. Epub 2019 Jun 11.
Radiotherapy is one of the main treatment modalities for head and neck cancers. To minimize damage to normal tissues during radiotherapy, various methods of stabilization have been used, including thermoplastic facemasks and repositioning stents. The goal is to assess the effect of using a customized oral repositioning stent on patient positioning during the course of radiotherapy.
Ten consecutive patients scheduled to undergo intensity modulated radiation therapy (IMRT) for cancers of the maxillary sinus, nasal cavity, or oral cavity were recruited to participate in the study (ST group). These patients were matched to 2 retrospective cohorts, one using the original repositioning stent design (OB group), and the other with no stabilization stent (NB group). Hard baseplate wax was used to create a customized wax pattern of the proposed acrylic stent chairside, and processed in heat-cured clear hard acrylic. Relative stability of the daily patient setup was assessed by comparing measurements from surrogate bony landmarks to radiation isocentres obtained from the initial reconstructed planning computed tomograph (CT) to each daily KeV image.
There was no stent fracture or distortion throughout treatments, and no patients' treatments were required to be aborted, delayed, or replanned. Mean 3D deviations for the ST, OB, and NB groups were 0.29 ± 0.10 cm, 0.32 ± 0.14 cm, and 0.31 ± 0.13 cm, respectively. The ANOVA test revealed no significant difference in triangulated variations between the treatment groups (F = 0.18, p = 0.84). Patient stability data demonstrated mean vertical, longitudinal, and lateral variations that did not appear different when compared to 2 retrospective cohorts. Although the deviations were not statistically significant between matched cohorts, the added durability of the stent and comfort for patients, without affecting IMRT timeline, are considered clinically significant.
By using a customized repositioning stent, it is possible to maintain patient stability comparable to prior protocols and within the range of clinical guidelines, while providing superior comfort and ease of insertion to the patients.
放射治疗是头颈部癌症的主要治疗方法之一。为了在放射治疗过程中最大限度地减少对正常组织的损伤，已经使用了各种稳定方法，包括热塑性面罩和重新定位支架。目的是评估在放射治疗过程中使用定制口腔重新定位支架对患者定位的影响。
招募了 10 名连续的上颌窦、鼻腔或口腔癌症接受调强放射治疗（IMRT）的患者（ST 组）参加研究。这些患者与两个回顾性队列相匹配，一个使用原始重新定位支架设计（OB 组），另一个没有稳定支架（NB 组）。在现场使用硬基托蜡制作拟议的丙烯酸支架的定制蜡模型，并在热固化透明硬丙烯酸中进行处理。通过将来自初始重建计划计算机断层扫描（CT）的替代骨性标志与从每日 KeV 图像获得的辐射等中心进行比较，评估每日患者设置的相对稳定性。
在整个治疗过程中，支架没有断裂或变形，也没有患者的治疗需要中止、延迟或重新计划。ST、OB 和 NB 组的平均 3D 偏差分别为 0.29 ± 0.10cm、0.32 ± 0.14cm 和 0.31 ± 0.13cm。方差分析显示，治疗组之间的三角变异没有显著差异（F = 0.18，p = 0.84）。患者稳定性数据表明，与 2 个回顾性队列相比，垂直、纵向和横向变化的平均值没有差异。尽管匹配队列之间的偏差没有统计学意义，但支架的耐用性和患者的舒适度增加，而不影响 IMRT 时间线，被认为具有临床意义。
通过使用定制的重新定位支架，可以保持与先前方案相当的患者稳定性，并在临床指南范围内，同时为患者提供更好的舒适度和插入的便利性。
