Department of Radiation Oncology, Ankara University Faculty of Medicine, Ankara, Turkey.
Department of Radiology, University of Health Sciences, Diskapi Yildirim Beyazit Training and Research Hospital, Ankara, Turkey.
Head Neck. 2023 Nov;45(11):2907-2914. doi: 10.1002/hed.27524. Epub 2023 Sep 22.
We aimed to describe the association between trigeminal nerve (TN) dose and toxicity and determine a threshold value that leads to TN toxicity in patients with parotid tumors treated with adjuvant conventional fractionated radiation therapy.
Eighteen patients who underwent adjuvant radiotherapy (RT) between 2013 and 2018 were included in this retrospective study. TN and its branches were outlined subsequently on the planning CT scans. The doses received by TN were obtained based on the dose-volume histogram. The dose and toxicity relationship was investigated over the total prescribed dose. RT-related toxicity was graded according to Common Terminology Criteria for Adverse Events V4.0 (CTCAEv4.0).
The median follow-up was 29.5 months. After RT, 61% of patients had Grade I-II late TN toxicity divided into Grade I in 4 (22%) and Grade II in 7 (39%) patients. TN injury symptoms were as follows: loss of sensation in the chin area in 3, difficulty in jaw movements in 3, and paresthesia in 5 patients. The total RT dose (p = 0.001), Dmax (p = 0.001), PTV-TN Dmax (p = 0.001), D1cc (p = 0.004), D0.5cc (p = 0.001), and D0.1cc (p = 0.01) had a significant effect on TN toxicity. Cut-off values leading to toxicity were determined as 66, 65.5, 65.25, 63.6, and 62.7 Gy for Dmax, PTV-TN Dmax, D0.1cc, D 0.5cc, and D1cc, respectively.
Radiation-induced TN injury in head and neck cancer patients may further be investigated in clinically prospective trials by virtue of high toxicity rates with current RT doses in our retrospectively designed dosimetric study in parotid tumors.
我们旨在描述三叉神经（TN）剂量与毒性之间的关系，并确定在接受辅助常规分割放射治疗的腮腺肿瘤患者中导致 TN 毒性的阈值。
本回顾性研究纳入了 2013 年至 2018 年间接受辅助放疗（RT）的 18 名患者。在计划 CT 扫描上对 TN 及其分支进行轮廓勾画。根据剂量-体积直方图获得 TN 接受的剂量。研究了在总规定剂量下剂量与毒性的关系。根据常见不良事件术语标准第四版（CTCAEv4.0）对 RT 相关毒性进行分级。
中位随访时间为 29.5 个月。在 RT 后，61%的患者出现 I-II 级晚期 TN 毒性，分为 4 例（22%）I 级和 7 例（39%）II 级。TN 损伤症状如下：颏区感觉丧失 3 例，咀嚼困难 3 例，感觉异常 5 例。总 RT 剂量（p=0.001）、Dmax（p=0.001）、PTV-TN Dmax（p=0.001）、D1cc（p=0.004）、D0.5cc（p=0.001）和 D0.1cc（p=0.01）对 TN 毒性有显著影响。确定导致毒性的临界值分别为 Dmax、PTV-TN Dmax、D0.1cc、D0.5cc 和 D1cc 的 66、65.5、65.25、63.6 和 62.7 Gy。
在我们回顾性设计的腮腺肿瘤剂量学研究中，由于目前 RT 剂量导致毒性较高，辐射诱导的头颈部癌症患者的 TN 损伤可能会在未来的临床前瞻性试验中进一步研究。
