Gujral Dorothy M, Chahal Navtej, Senior Roxy, Harrington Kevin J, Nutting Christopher M
Head and Neck Unit, Royal Marsden Hospital, London, United Kingdom.
Department of Echocardiography, Royal Brompton Hospital, London, United Kingdom.
Radiother Oncol. 2014 Jan;110(1):31-8. doi: 10.1016/j.radonc.2013.08.009. Epub 2013 Sep 14.
Carotid arteries frequently receive significant doses of radiation as collateral structures in the treatment of malignant diseases. Vascular injury following treatment may result in carotid artery stenosis (CAS) and increased risk of stroke and transient ischaemic attack (TIA). This systematic review examines the effect of radiotherapy (RT) on the carotid arteries, looking at the incidence of stroke in patients receiving neck radiotherapy. In addition, we consider possible surrogate endpoints such as CAS and carotid intima-medial thickness (CIMT) and summarise the evidence for radiation-induced carotid atherosclerosis.
From 853 references, 34 articles met the criteria for inclusion in this systematic review. These papers described 9 studies investigating the incidence of stroke/TIA in irradiated patients, 11 looking at CAS, and 14 examining CIMT.
The majority of studies utilised suboptimally-matched controls for each endpoint. The relative risk of stroke in irradiated patients ranged from 1.12 in patients with breast cancer to 5.6 in patients treated for head and neck cancer. The prevalence of CAS was increased by 16-55%, with the more modest increase seen in a study using matched controls. CIMT was increased in irradiated carotid arteries by 18-40%. Only two matched-control studies demonstrated a significant increase in CIMT of 36% and 22% (p=0.003 and <0.001, respectively). Early prospective data demonstrated a significant increase in CIMT in irradiated arteries at 1 and 2 years after RT (p<0.001 and <0.01, respectively).
The incidence of stroke was significantly increased in patients receiving RT to the neck. There was a consistent difference in CAS and CIMT between irradiated and unirradiated carotid arteries. Future studies should optimise control groups.
在恶性疾病治疗中，颈动脉作为侧支结构常常会接受大剂量辐射。治疗后血管损伤可能导致颈动脉狭窄（CAS），并增加中风和短暂性脑缺血发作（TIA）的风险。本系统评价旨在研究放射治疗（RT）对颈动脉的影响，观察接受颈部放疗患者的中风发生率。此外，我们考虑了诸如CAS和颈动脉内膜中层厚度（CIMT）等可能的替代终点，并总结了辐射诱发颈动脉粥样硬化的证据。
从853篇参考文献中，有34篇文章符合纳入本系统评价的标准。这些论文描述了9项研究照射患者中风/TIA发生率的研究、11项观察CAS的研究以及14项检查CIMT的研究。
大多数研究针对每个终点使用的对照组匹配不佳。接受放疗患者中风的相对风险范围为，乳腺癌患者为1.12，头颈部癌患者为5.6。CAS的患病率增加了16%-55%，在一项使用匹配对照组的研究中增加幅度较小。接受放疗的颈动脉CIMT增加了18%-40%。只有两项匹配对照研究显示CIMT显著增加，分别为36%和22%（p分别为0.003和<0.001）。早期前瞻性数据显示，放疗后1年和2年，照射动脉的CIMT显著增加（p分别<0.001和<0.01）。
接受颈部放疗的患者中风发生率显著增加。照射和未照射的颈动脉在CAS和CIMT方面存在持续差异。未来的研究应优化对照组。
