Department of Radiation Oncology, the Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
Department of Biostatistics, the Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada.
Cancer. 2017 Oct 1;123(19):3691-3700. doi: 10.1002/cncr.30803. Epub 2017 Jun 13.
Osteoradionecrosis (ORN) of the mandible is a late toxicity affecting patients treated with radiotherapy for head and neck malignancies. To the authors' knowledge, ORN has no standardized grading system and its reporting is based on retrospective findings in heterogeneous patient populations. The rate of ORN in the era of intensity-modulated radiotherapy (IMRT) still is unknown.
The authors report the incidence of ORN from prospectively collected data regarding 1196 patients who were diagnosed with squamous cell carcinoma of the oropharynx and treated with curative-intent IMRT, with or without concomitant systemic treatment, from January 2005 to December 2014. Each case of ORN was graded according to its severity. Clinical and dosimetric comparisons were performed between patients with ORN and a matched control cohort of patients without ORN.
The actuarial rate of ORN of the mandible was 3% at 1 year, 5% at 3 years, and 7% at 5 years. On multivariable analysis, smoking (hazard ratio, 1.9; 95% confidence interval, 1.07-3.4 [P = .03]) and T classification (hazard ratio, 1.78; 95% confidence interval, 1.02-3.1 [P = .041]) were found to be statistically significant risk factors. The presence of cardiovascular comorbidities, use of bisphosphonates, and pre-IMRT dental extractions were found to be different between the matched cohorts. The mandibular volume receiving 50 grays (Gy) (in cm ) and the volume receiving 60 Gy (in cm ) were found to be associated with ORN on multivariable analysis in the matched cohort patients receiving an IMRT regimen of 2 Gy per fraction.
ORN is relatively uncommon among patients with oropharyngeal carcinoma who are treated with IMRT, but continues to occur beyond 5 years after treatment. Modifiable risk factors that are associated with higher rates of ORN include smoking and the use of bisphosphonates. Minimizing the volumes of the mandible receiving >50 Gy or > 60 Gy also may have an effect on the ORN rate. Cancer 2017;123:3691-3700. © 2017 American Cancer Society.
下颌骨放射性骨坏死（ORN）是一种影响头颈部恶性肿瘤放疗后患者的迟发性毒性。据作者所知，ORN 尚无标准化的分级系统，其报告基于回顾性发现，这些发现来自于异质性患者群体。调强放疗（IMRT）时代的 ORN 发生率仍不清楚。
作者报告了前瞻性收集的数据中 ORN 的发生率，这些数据涉及 1196 例经诊断为口咽鳞癌的患者，他们在 2005 年 1 月至 2014 年 12 月期间接受了根治性 IMRT 治疗，无论是否联合全身治疗。根据严重程度对每个 ORN 病例进行分级。对 ORN 患者和无 ORN 的匹配对照组患者进行临床和剂量学比较。
下颌骨 ORN 的 1 年、3 年和 5 年 actuarial 发生率分别为 3%、5%和 7%。多变量分析发现，吸烟（风险比，1.9；95%置信区间，1.07-3.4[P = .03]）和 T 分类（风险比，1.78；95%置信区间，1.02-3.1[P = .041]）是统计学上的显著危险因素。在匹配队列中，发现心血管合并症的存在、使用双膦酸盐和 IMRT 前拔牙存在差异。在接受 2 Gy 分割的 IMRT 方案的匹配队列患者中，发现下颌骨接受 50 Gy（Gy）（cm ）和接受 60 Gy（cm ）的体积与 ORN 相关。
在接受 IMRT 治疗的口咽癌患者中，ORN 相对少见，但在治疗后 5 年仍持续发生。与更高 ORN 发生率相关的可改变危险因素包括吸烟和使用双膦酸盐。尽量减少下颌骨接受>50 Gy 或>60 Gy 的体积也可能对 ORN 发生率有影响。癌症 2017；123：3691-3700。©2017 美国癌症协会。
