Grant Stephen R, Williamson Tyler D, Stieb Sonja, Shah Shalin J, David Fuller C, Rosenthal David I, Frank Steven J, Garden Adam S, Morrison William H, Phan Jack, Moreno Amy C, Reddy Jay P, Cardoso Richard C, Liu Amy Y, Wu Richard Y, Gunn G Brandon
Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Adv Radiat Oncol. 2020 Aug 25;5(6):1359-1363. doi: 10.1016/j.adro.2020.08.007. eCollection 2020 Nov-Dec.
Tongue-deviating oral stents (TDOS) are commonly used during unilateral neck radiation therapy to reduce unnecessary dose to nontarget oral structures. Their benefit in the setting of highly conformal treatment techniques, however, is not defined. The goal of this study was to investigate the potential benefit of TDOS use on dosimetric parameters in unilateral intensity modulated radiation therapy (IMRT) and intensity modulated proton therapy (IMPT).
A total of 16 patients with T1-2 tonsil cancer treated at a single institution were selected, of which 8 were simulated/treated with a TDOS and 8 without a TDOS. All received definitive unilateral IMRT to a dose of 66 Gy in 30 fx. IMPT plans were generated for each patient for study purposes and optimized according to standard institutional practice.
For IMRT plans, the presence of a TDOS (vs without) was associated with a significantly lower oral mucosa mean dose (31.4 vs 35.3 Gy; = .020) and V30 (42.7% vs 57.1%; = .025). For IMPT plans, the presence of TDOS (vs without) was not associated with any improvement in oral mucosa mean dose (18.3 vs 19.9 Gy; = .274) or V30 (25.0% vs 26.2%; = .655). IMPT plans without TDOS compared with IMRT plans with TDOS demonstrated reduced oral mucosa mean dose ( < .001) and V30 ( < .001).
The use of a TDOS for the unilateral treatment of well-lateralized tonsil cancers was associated with oral mucosa sparing for IMRT, but not for IMPT. Moreover, mucosa sparing was improved for IMPT plans without a TDOS compared to IMRT plans with a TDOS.
舌偏位口腔支架（TDOS）常用于单侧颈部放射治疗，以减少非靶口腔结构所接受的不必要剂量。然而，在高适形治疗技术背景下其益处尚不明确。本研究的目的是探讨在单侧调强放射治疗（IMRT）和调强质子治疗（IMPT）中使用TDOS对剂量学参数的潜在益处。
选取在单一机构接受治疗的16例T1-2期扁桃体癌患者，其中8例在模拟/治疗时使用了TDOS，8例未使用。所有患者均接受单侧根治性IMRT，剂量为66 Gy，分30次照射。为每位患者生成IMPT计划用于研究目的，并根据机构标准做法进行优化。
对于IMRT计划，使用TDOS（与未使用相比）与口腔黏膜平均剂量显著降低相关（31.4 Gy对35.3 Gy；P = 0.020）以及V30降低相关（42.7%对57.1%；P = 0.025）。对于IMPT计划，使用TDOS（与未使用相比）与口腔黏膜平均剂量（18.3 Gy对19.9 Gy；P = 0.274）或V30（25.0%对26.2%；P = 0.655）的任何改善均无关。未使用TDOS的IMPT计划与使用TDOS的IMRT计划相比，口腔黏膜平均剂量降低（P < 0.001）且V30降低（P < 0.001）。
对于单侧定位良好的扁桃体癌治疗，使用TDOS可使IMRT的口腔黏膜得到保护，但对IMPT则不然。此外，与使用TDOS的IMRT计划相比，未使用TDOS的IMPT计划的黏膜保护效果更佳。
