探讨经直肠超声检查（ERUS）在直肠癌新辅助放化疗后术前评估中的应用价值。

选择2016年1至12月中山大学附属第六医院收治的90例直肠癌患者。所有患者均接受了新辅助放化疗，并于全直肠系膜切除术（TME）前进行了ERUS，其中64例患者在新辅助放化疗前后均接受了ERUS，26例患者仅于新辅助放化疗后接受了ERUS。应用配对样本比较的Wilcoxon秩和检验比较直肠癌患者新辅助化疗前后肿瘤距肛缘距离、厚度及累及肠管长度差异。以术后病理分期诊断结果作为金标准，计算ERUS评估直肠癌新辅助放化疗后直肠癌T分期的准确性。

与新辅助放化疗前比较，新辅助放化疗后患者肿瘤下缘距肛缘的距离增加[（51.68±19.81）mm vs （58.63±21.71）mm]，肿瘤厚度减小[（14.92±5.30）mm vs （9.73±2.50）mm]，肿瘤累及肠管长度缩短[（40.82±9.18）mm vs （26.10±10.07）mm]，且差异均有统计学意义（Z=4.996、6.153、6.076，P均<0.01）。90例患者术后病理诊断为完全缓解pT0期15例，pT1期3例，pT2期30例，pT3期42例。术前ERUS诊断为完全缓解uT0期9例，uT1期1例，uT2期18例，uT3期59例，uT4期3例。ERUS对直肠癌新辅助放化疗后T分期的诊断准确性分别为uT0期82.2%（74/90）、uT1期96.7%（87/90）、uT2期66.7%（60/90）、uT3期67.8%（61/90）和uT4期96.7%（87/90），T分期总的诊断准确性为82.2%（74/90）。

ERUS能够有效记录直肠癌新辅助放化疗前后肿瘤形态学变化，有助于对肿瘤距肛缘距离、肿瘤累及范围及浸润深度进行术前再评估。

To investigate the value of endorectal ultrasonography (ERUS) in preoperative assessment of rectal cancer post neoadjuvant chemoradiation therapy.

From Jan. 2016 to Dec. 2016, 90 rectal cancer patients who underwent preoperative neoadjuvant chemoradiation therapy and total mesorectal excision surgery in the Sixth Affiliated Hospital of Sun Yat-Sen University were retrospectively analyzed, and all patients underwent ERUS examination post neoadjuvant chemoradiation therapy. Of these, 64 patients were evaluated by ERUS pre and post neoadjuvant chemoradiation therapy and 26 patients were evaluated only post neoadjuvant chemoradiation therapy. Wilcoxon rank sum test for paired sample was performed to compare the distance from inferior margin of tumor to anal margin, the length and thickness of the tumor pre and post neoadjuvant chemoradiation therapy respectively in rectal cancer. Taken pathologic findings as golden standard, the accuracy of T staging assessed by ERUS post neoadjuvant chemoradiation therapy was evaluated.

Compared with pre neoadjuvant chemoradiation therapy, the distance from inferior margin of tumor to anal margin significantly increased after neoadjuvant chemoradiation therapy [(58.63±21.71) mm vs (51.68±19.81) mm], and the length [(26.10±10.07) mm vs (40.82±9.18) mm] and thickness [(9.73±2.50) mm vs (14.92±5.30) mm] of tumor also evidently decreased post neoadjuvant chemoradiation therapy, respectively (Z were 4.996, 6.153 and 6.076, all P<0.01). The final pathological T stage was pathologic complete response (pCR) or pT0 in 15 patients, pT1 in 3 patients, pT2 in 30 patients and pT3 in 42 patients. The diagnostic accuracy of T staging of rectal cancer post neoadjuvant chemoradiation therapy for ERUS was uT0 82.2% (74/90), uT1 96.7% (87/90), uT2 66.7% (60/90), uT3 67.8% (61/90) and uT4 96.7% (87/90), and the overall accuracy was 82.2% (74/90).

ERUS could effectively record the morphological changes of rectal cancer pre and post neoadjuvant chemoradiation therapy, which may contribute to the re-evaluation of the distance from inferior tumor margin to anal margin and the range and depth of tumor involvement pre surgical resection.