Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Department of Neurosurgery, Japanese Red Cross Fukui Hospital, Fukui, Japan.
Cerebrovasc Dis. 2023;52(5):543-551. doi: 10.1159/000528622. Epub 2023 Jan 30.
Radiation-induced carotid artery stenosis (RI-CS) is known as one of long-term side effects of radiotherapy for head and neck cancer (HNC). However, the clinical time course after irradiation has been poorly understood. We aimed to investigate the natural history of radiation-induced carotid atherosclerosis, comparing the patients who received radiotherapy for HNC with the patients who were treated without radiotherapy.
The patients who received treatment of HNC at Department of Otolaryngology, Head and Neck Surgery of Kyoto University Hospital, from November 2012 to July 2015 were enrolled. The patients were assigned into the RT group and the control group, depending on whether radiotherapy was planned or not. Annual carotid ultrasound was performed from the enrollment to 5 years. The increase of mean intima-media thickness (IMT) at common carotid artery from the enrollment (Δmean IMT) was evaluated.
Fifty-six patients in the RT group and 25 patients in the control group were enrolled. From 5-year follow-up data, the significant higher increase of Δmean IMT was consistently observed in the RT group than in the control group after 2 years. The RT group presented a 7.8-fold increase of mean IMT compared to the control group (0.060 mm per year in the RT group and 0.008 mm per year in the control group). Cumulative incidence curves obtained from the analysis of all vessels revealed that the RT group presented higher incidence of Δmean IMT ≥0.25 mm than the control group (p < 0.01). In the RT group, the patients with mean IMT ≥1.0 mm at enrollment exhibited significantly higher incidence of Δmean IMT ≥0.25 mm than the patients with mean IMT <1.0 mm (p < 0.01).
Radiotherapy for HNC induces continuous carotid mean IMT progression. The irradiated carotid arteries with mean IMT ≥1.0 mm before radiotherapy presented earlier IMT progression than those with mean IMT <1.0 mm.
放射性颈动脉狭窄（RI-CS）是头颈部癌症（HNC）放疗的长期副作用之一。然而，其在照射后的临床进程仍知之甚少。我们旨在研究放射性颈动脉粥样硬化的自然病史，比较接受 HNC 放疗的患者和未接受放疗的患者。
我们招募了 2012 年 11 月至 2015 年 7 月在京都大学医院耳鼻喉科接受 HNC 治疗的患者。根据是否计划放疗，患者被分为 RT 组和对照组。从入组开始，每年进行颈动脉超声检查，随访 5 年。评估从入组时颈总动脉平均内膜中层厚度（IMT）的增加（Δmean IMT）。
共有 56 例 RT 组和 25 例对照组患者入组。从 5 年随访数据来看，在入组后 2 年，RT 组的 Δmean IMT 增加显著高于对照组。与对照组相比，RT 组的平均 IMT 增加了 7.8 倍（RT 组每年增加 0.060mm，对照组每年增加 0.008mm）。从所有血管的分析中获得的累积发病率曲线表明，RT 组的 Δmean IMT≥0.25mm 的发生率高于对照组（p<0.01）。在 RT 组中，入组时 IMT≥1.0mm 的患者，Δmean IMT≥0.25mm 的发生率显著高于 IMT<1.0mm 的患者（p<0.01）。
HNC 的放疗会导致颈动脉平均 IMT 持续进展。放疗前 IMT≥1.0mm 的放射性颈动脉较 IMT<1.0mm 的放射性颈动脉更早出现 IMT 进展。
