Radiotherapy for Nasopharyngeal Carcinoma as a Risk Factor for Extracranial Carotid Stenosis. Is It Also a Risk Factor for Intracranial Arteries? A Retrospective Case-control Study
PY Chu, JPK Tsang, WY Wong, WCS Chan, WL Poon, MK Yuen, YC Wong
Hong Kong J Radiol 2015;18:180-6
DOI: 10.12809/hkjr1514293
Objective: Carotid duplex ultrasound has revealed that radiotherapy is associated with stenosis of the extracranial carotid arteries in patients with nasopharyngeal carcinoma (NPC). The objective of the study was to determine the relationship between intracranial and extracranial arterial stenosis and radiation therapy using computed tomographic angiography (CTA) in patients with NPC and a history of symptomatic cerebral ischaemia.
Methods: This was a retrospective case-control study conducted in Pok Oi Hospital, Hong Kong. All consecutive CTA scans of the head and neck from January 2008 to December 2009 in patients with a history of transient ischaemic attack or ischaemic stroke were included. Intracranial arterial (including intracranial internal carotid artery, M1 segment of middle cerebral artery, and intracranial vertebral artery) and extracranial arterial stenosis was defined as a diameter reduction of ≥50%. Patient demographics, history of radiotherapy for NPC, smoking history, medical history of diabetes mellitus, hypertension, and hyperlipidaemia were recorded.
Results: A total of 152 patients (105 men and 47 women; mean [standard deviation] age, 64.9 [11.6] years) were enroled. Of them, 19 (12.5%) had a history of NPC and treatment by radiotherapy; 133 (87.5%) patients did not receive any head and neck radiotherapy. A statistically significantly increased risk of common carotid artery stenosis (p < 0.001; adjusted odds ratio = 34.510) and extracranial arterial stenosis (p = 0.001; adjusted odds ratio = 6.607) was observed in patients with NPC treated with radiotherapy compared with those without irradiation. Radiotherapy did not increase the risk of intracranial arterial stenosis (10/19 [52.6%] vs. 75/133 [56.4%]; p = 0.710).
Conclusion: Radiotherapy for NPC is associated with an increased risk for stenosis of the extracranial arteries, particularly the common carotid artery. Radiotherapy for NPC was not shown to increase the risk of intracranial artery stenosis based on CTA findings in patients with symptomatic cerebral ischaemia.
中文摘要
鼻咽癌放射治療作為誘發顱外頸動脈狹窄的危險因素之一，是否也為顱內動脈的危險因素？回顧性病例對照研究
朱炳容、曾佩琪、王慧瑜、陳煥章、潘偉麟、袁銘強、王耀忠
目的：頸動脈多普勒超聲顯示放射治療與鼻咽癌（NPC）患者的顱外動脈狹窄有關。本研究的目的在於運用電腦斷層血管造影術（CTA）確定鼻咽癌以及有症狀性腦缺血病史的人群中，其顱內外動脈狹窄與放射治療的關係。
方法：本回顧性病例對照研究在香港博愛醫院進行。2008年1月至2009年12月期間接受CTA掃描的短暫性腦缺血發作或缺血性中風患者被陸續納入研究。顱內動脈（包括顱內頸內動脈、大腦中動脈M1段和顱內椎動脈）和顱外動脈狹窄的定義為50%或以上的直徑減小。本研究記錄了患者的人口學數據、NPC的放射治療病史、吸煙史、糖尿病史、高血壓和高血脂。
結果：總計152名患者納入研究（105名男性和47名女性；平均年齡64.9歲，標準差11.6歲）。其中19人（12.5%）曾因NPC而接受放射治療，133人（87.5%）未接受任何頭頸部放射治療。與沒有接受放射治療的患者比較，接受放射治療的NPC患者的頸總動脈狹窄（調整後比值比=34.510；p<0.001）和顱外動脈狹窄（調整後的比值比=6.607；p=0.001）的風險顯著增加。然而放射治療沒有增加顱內動脈狹窄的風險（10/19〔52.6%〕比75/133〔56.4%〕；p=0.710）。
結論：NPC放射治療與顱外動脈狹窄的風險增加有關，尤其是頸總動脈。根據症狀性腦缺血患者的CTA掃描結果，NPC放射治療不會增加顱內動脈狹窄的風險。