Research Center for Charged Particle Therapy Hospital, National Institute of Radiological Sciences, Chiba, Japan.
Radiat Oncol. 2014 Apr 3;9(1):92. doi: 10.1186/1748-717X-9-92.
Osteoradionecrosis (ORN) is a critical complication after carbon ion (C-ion) or photon radiotherapy (RT) for head and neck tumors. However, the risk factors for ORN after C-ion RT remain unclear. Therefore, the present study aimed to investigate the effects of the dose-volume relationship on and risk factors for ORN development after C-ion RT. We, however, focused on the maxillary bone because most tumors treated with C-ion RT were primarily located in the sinonasal cavity.
The patients enrolled in this study received more than 10% of the prescribed total dose of 57.6 Gy equivalent (GyE) in 16 fractions to their maxilla. All patients were followed up for more than 2 years after C-ion RT. Those with tumor invasion to the maxilla before C-ion RT or local recurrence after the treatment were excluded from the study to accurately evaluate the effects of irradiation on the bone. Sixty-three patients were finally selected. The severity of ORN was assessed according to the Common Terminology Criteria for Adverse Events version 4.0. The correlation between clinical and dosimetric parameters and ORN incidence was retrospectively analyzed.
The median follow-up period was 79 months. Of the 63 enrolled patients, 26 developed ORN of grade ≥1. Multivariate analysis revealed that the maxilla volume receiving more than 50 GyE (V50) and the presence of teeth within the planning target volume were significant risk factors for ORN. Dose-volume histogram analysis revealed that V10 to V50 parameters were significantly higher in patients with ORN than in those without ORN.
V50 and the presence of teeth within the planning target volume were independent risk factors for the development of ORN after C-ion RT using a 16-fraction protocol.
骨放射性坏死（ORN）是头颈部肿瘤碳离子（C-离子）或光子放射治疗（RT）后的一种严重并发症。然而，C-离子 RT 后 ORN 的危险因素尚不清楚。因此，本研究旨在探讨剂量-体积关系及 C-离子 RT 后 ORN 发生的危险因素。然而，我们主要关注上颌骨，因为大多数接受 C-离子 RT 治疗的肿瘤主要位于鼻窦腔内。
本研究纳入的患者上颌骨接受的处方总剂量 57.6GyE 的 16 分次剂量超过 10%。所有患者在 C-离子 RT 后均随访超过 2 年。在 C-离子 RT 前有肿瘤侵犯上颌骨或治疗后局部复发的患者被排除在研究之外，以准确评估照射对骨骼的影响。最终选择了 63 例患者。根据不良事件通用术语标准 4.0 评估 ORN 的严重程度。回顾性分析临床和剂量学参数与 ORN 发生率的相关性。
中位随访时间为 79 个月。63 例入组患者中，26 例发生≥1 级 ORN。多变量分析显示，上颌骨接受超过 50GyE（V50）的体积和计划靶区（PTV）内存在牙齿是 ORN 的显著危险因素。剂量-体积直方图分析显示，ORN 患者的 V10 至 V50 参数明显高于无 ORN 患者。
在 16 分次方案中，V50 和 PTV 内存在牙齿是 C-离子 RT 后 ORN 发生的独立危险因素。
