超声联合诊断甲状腺乳头状癌颈淋巴结转移的应用价值

Value of a Combination of Ultrasound Examinations in Preoperative Diagnosis of Neck Lymph Node Metastasis in Papillary Thyroid Cancer

背景甲状腺乳头状癌(PTC)颈淋巴结转移的准确诊断会影响患者的手术方式与预后。目前常用超声判断淋巴结是否转移,但准确性不高。近年来超声造影和超声弹性成像有望提高诊断淋巴结转移的准确性。目的探究常规超声联合超声造影以及弹性成像在PTC颈淋巴结转移术前诊断中的应用价值。方法选择2015年12月—2017年12月上海市静安区闸北中心医院收治的PTC患者124例,根据术后的淋巴结病理结果将患者分为转移组53例和反应组71例。记录并比较两组常规超声征象〔淋巴结前后径(S)、横径(L),并计算L/S(L/S分为>2或≤2)、淋巴结边缘形态(规则/不规则)、淋巴门(有淋巴门/无淋巴门)、淋巴结皮质回声(低回声、等回声、高回声)、淋巴结钙化(无钙化/有钙化)、液化表现(无液化/有液化)、血流分布(中央型血流、周边型血流、混合型血流)、血流分级(0~2级)〕、超声造影〔淋巴结峰值强度(PI)、达峰时间(TP)、时间-强度曲线下面积、造影分布(均匀、不均)、灌注区(有、无)以及边界情况(不清、清楚)〕以及弹性成像数据〔超声实时组织弹性成像(RTE)评分〕。采用多因素Logistic回归分析研究PTC颈淋巴结转移的影响因素,采用AUC检验不同联合诊断的效能。结果转移组L/S、淋巴结边缘形态、淋巴门、血流分布、PI、造影分布和RTE评分高于反应组(P<0.05)。L/S、淋巴结边缘形态、淋巴门、血流分布、PI、造影分布和弹性评分为PTC颈淋巴结转移的影响因素(P<0.05)。PI、弹性评分、淋巴门、L/S联合诊断PTC颈淋巴结转移的AUC高于PI(Z=6.183,P<0.001)。联合诊断的拟合方程为Logit(P)=-13.168+2.888×L/S+4.232×淋巴门+0.159×PI+3.029×弹性评分。结论常规超声联合超声造影及弹性成像可有效提高诊断PTC颈淋巴结转移的准确率。

Background The degree of diagnostic accuracy of cervical lymph node metastasis of papillary thyroid cancer(PTC) can influence the surgical approach and patients' prognosis.Ultrasound is often used to determine the prevalence of lymph node metastasis,but it is not accurate enough.Recently,contrast-enhanced ultrasound and ultrasound elastography are expected to improve the accuracy of diagnosis of lymph node metastasis.Objective To explore the value of conventional ultrasound in combination with contrast-enhanced ultrasound and elastography in the preoperative diagnosis of cervical lymph node metastases in PTC.Methods We recruited 124 cases of PTC from Jing'an District Zhabei Central Hospital,Shanghai from December 2015 to December 2017 and divided them into metastasis group(n=53) and reactive group(n=71) according to the postsurgical pathological findings for cervical lymph node.The routine ultrasound features〔anteroposterior diameter(S) and transverse diameter(L) of cervical lymph nodes,and L/S ratio(L/S score > 2 or ≤ 2),marginal morphology of cervical lymph nodes(regular/irregular),prevalence of lymphatic hilum,echo degree of cervical lymph node cortex (hypoechoic, isoechoic,hyperechoic),prevalence of cervical lymph node calcification and liquefaction,blood flow distribution pattern (central,peripheral,mixed),and blood flow grade(0-2)〕,contrast-enhanced ultrasound〔peak intensity(PI),time to peak(TP),area under the time-intensity curve (AUC),enhancement pattern(homogeneous or uneven), prevalence of perfusion area,and boundary condition (unclear or clear)〕,and elastography data〔real-time elastography (RTE)〕were collected and compared.Logistic regression was used to investigate the influencing factors for cervical lymph node metastasis of PTC.And AUC analysis was performed to test the diagnostic accuracy of different combinations of ultrasound tools.Results Compared with the reactive group,metastasis group had greater L/S ratio,better marginal morphology,higher prevalence of lymphatic hilum,better blood flow distribution pattern and enhancement pattern,higher PI value and RTE score (P<0.05).L/S ratio,marginal morphology,lymphatic hilum,blood flow distribution pattern,PI value,enhancement pattern,and RTE score had significant influence on the occurrence of cervical lymph node metastasis in PTC(P<0.05).The AUC of the PI value,RTE score,lymphatic hilum,combined with L/S ratio for the diagnosis of cervical lymph node metastasis in PTC was greater than that of PI value alone(Z=6.183,P<0.001).The fitting equation for the combined diagnosis was Logit (P)=-13.168+2.888×L/S ratio+4.232×lymphoid hilum +0.159×PI value+3.029×RTE score.Conclusion Conventional ultrasound combined with contrast-enhanced ultrasound and elastography can effectively improve the accuracy of PTC cervical lymph node metastasis diagnosis.