直肠腔内超声对直肠癌术前新辅助放化疗疗效评估

Value of Endorectal Utrasound for Staging Rectal Cancer Following Neoadjuvant Chemoradiation Therapy

目的评估直肠腔内超声(endorectal ultrasound,ERUS)对直肠癌术前新辅助放化疗后分期的应用价值。方法回顾性分析2011年9月至2012年9月北京协和医院收治的直肠癌患者62例,所有患者在放化疗前后完成ERUS检查并分期,最终经直肠全系膜切除术(total mesorectal excision,TME)切除肿瘤,并进行病理分期,比较ERUS分期与手术病理分期结果。结果 62例患者中8例放化疗后肿瘤消失,达到病理完全缓解(pT0N0),但ERUS均未准确诊断;30例对放化疗反应较好的患者中仅7例肿瘤浸润深度超声分期(uT分期)准确。ERUS的uT总准确性仅40.3%(25例),过高分期58.1%(36例),过低分期1.6%(1例)。ERUS诊断转移淋巴结的敏感性、特异性、阳性预测值、阴性预测值分别为60.0%、84.6%、42.9%、91.7%。结论 ERUS对直肠癌放化疗后肿瘤浸润深度超声分期(uT分期),尤其是对放化疗反应较好的肿瘤分期准确性偏低,且无法诊断肿瘤完全病理缓解。ERUS对淋巴结转移诊断的特异性和阴性预测值较高,可对直肠癌预后作出很好的预判。

Objective To assess the value of endorectal ultrasound （ERUS） for staging rectal cancer after neoadjuvant chemoradiation. Methods We retrospectively analyed the clinical data of 62 patients with rectal cancer between September 2011 and September 2012 in our hospital, ERUS was performed before and after chemoradiation therapy in all patients. All patients underwent subsequent total mesorectal excision （TEM） and completed pathologic staging. The results of ERUS were compared with the postoperatively pathologic staging. Results After chemoradiation, 8 patients had no residual disease at pathologic staging （pTON0） which was not correctly predicted by ERUS. Of 30 patients who responded well to the chemoradiation therapy, only 7 achieved correct ultrasonic staging （uT）. The overall accuracy of ERUS for uT was only 40. 3 % （25/62）, while 36 pa- tients （58.1% ） were overstaged and 1 patient （ 1.6% ） was understaged. The sensitivity, specificity, and pos- itive and negative predictive values for nodal staging were 60. 0%, 84. 6%, 42.9%, 91.7%, respectively. Conclusions The ERUS uT of rectal cancer after chemoradiation is inaccurate, especially in patients with evidence of response. Meanwhile, ERUS cannot reliably predict tumor pathological complete remission. However,ERUS has high specificity and negative predictive value for nodal staging and therefore is valuable in predicting the prognosis