Gunma University Heavy Ion Medical Center, Maebashi, Japan.
Gunma University Heavy Ion Medical Center, Maebashi, Japan.
Radiother Oncol. 2017 Oct;125(1):36-40. doi: 10.1016/j.radonc.2017.08.014. Epub 2017 Aug 31.
We aimed to evaluate the relationship between brainstem necrosis and dose-volume histograms in patients with head and neck tumors after carbon-ion radiotherapy.
We evaluated 85 patients with head and neck tumors who underwent carbon-ion radiotherapy and were followed-up for ≥12months. Brainstem necrosis was evaluated using the Common Terminology Criteria for Adverse Events (version 4.0).
The median follow-up was 24months, and four patients developed grade 1 brainstem necrosis, with 2-year and 3-year cumulative rates of 2.8% and 6.5%, respectively. Receiver operating characteristic curve analysis revealed the following significant cut-off values: a maximum brainstem dose of 48Gy (relative biological effectiveness [RBE]), D1cm of 27Gy (RBE), V40Gy (RBE) of 0.1cm, V30Gy (RBE) of 0.7cm, and V20Gy (RBE) of 1.4cm. Multivariate analysis revealed that V30Gy (RBE) was most significantly associated with brainstem necrosis. The 2-year cumulative rates were 33% and 0% for V30Gy (RBE) of ≥0.7cm and <0.7cm, respectively (p<0.001).
The present study indicated that the dose constraints might help minimize brainstem necrosis after carbon-ion radiotherapy.
本研究旨在评估碳离子放疗后头颈部肿瘤患者脑干坏死与剂量-体积直方图的关系。
我们评估了 85 例接受碳离子放疗且随访时间≥12 个月的头颈部肿瘤患者。采用常见不良事件术语标准（第 4.0 版）评估脑干坏死。
中位随访时间为 24 个月，4 例患者发生 1 级脑干坏死，2 年和 3 年累积发生率分别为 2.8%和 6.5%。受试者工作特征曲线分析显示以下显著截断值：最大脑干剂量 48Gy（相对生物效应[RBE]）、D1cm 为 27Gy（RBE）、V40Gy（RBE）为 0.1cm、V30Gy（RBE）为 0.7cm 和 V20Gy（RBE）为 1.4cm。多因素分析显示，V30Gy（RBE）与脑干坏死最显著相关。V30Gy（RBE）≥0.7cm 和<V0.7cm 的 2 年累积发生率分别为 33%和 0%（p<0.001）。
本研究表明，剂量限制可能有助于最小化碳离子放疗后脑干坏死的发生。
