Liang Xue, Zhang Jingyang, Peng Guang, Li Jiyao, Bai Sen
State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu, China.
J Dent Sci. 2016 Mar;11(1):1-7. doi: 10.1016/j.jds.2015.09.003. Epub 2015 Dec 17.
BACKGROUND/PURPOSE: The exact dose of intensity-modulated radiation therapy (IMRT) associated with tooth damage is mostly unknown. We aim to evaluate the severity of dental lesions after IMRT and the correlation with the radiation dose to the dentition in patients with nasopharyngeal carcinoma (NPC).
This was a cross-sectional study of 42 patients with NPC who completed IMRT in 2011. Each premolar tooth was divided into 13 sites. Teeth were evaluated using a validated index and subsequently categorized at each divided site. The relationship between dose distribution and the caries severity score was analyzed using logistic models. The odds of developing caries damage were evaluated using odds ratios.
A total of 4342 sites from 334 premolar teeth were evaluated. For sites exposed to 30-60 Gy, the odds of developing caries damage were 12-200 times greater compared with sites unexposed to IMRT. A new radiation caries lesion was likely to occur when the dose was >35.8 Gy after 17 days' radiation therapy (P < 0.05).
The findings suggest that new tooth damage was likely to occur at doses > 35.8 Gy, and care should be taken throughout the treatment planning process to limit tooth doses to < 50 Gy in NPC patients.
背景/目的：与牙齿损伤相关的调强放射治疗（IMRT）的确切剂量大多未知。我们旨在评估鼻咽癌（NPC）患者接受IMRT后牙齿病变的严重程度以及与牙列辐射剂量的相关性。
这是一项对2011年完成IMRT的42例NPC患者的横断面研究。每颗前磨牙分为13个部位。使用经过验证的指数对牙齿进行评估，随后在每个划分部位进行分类。使用逻辑模型分析剂量分布与龋齿严重程度评分之间的关系。使用比值比评估发生龋齿损伤的几率。
共评估了334颗前磨牙的4342个部位。对于暴露于30 - 60 Gy的部位，与未接受IMRT的部位相比，发生龋齿损伤的几率高12 - 200倍。放射治疗17天后，当剂量>35.8 Gy时，可能会出现新的放射性龋损（P < 0.05）。
研究结果表明，剂量>35.8 Gy时可能会出现新的牙齿损伤，在整个治疗计划过程中应注意将NPC患者的牙齿剂量限制在<50 Gy。
