Chen Limei, Liu Xiaoyin, Zhang Wenjing, Qin Si, Wang Yimin, Lin Jing, Chen Qiu, Liu Guangjian
Department of Medical Ultrasonics, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Ann Transl Med. 2022 Jun;10(12):666. doi: 10.21037/atm-22-2418.
Preoperative chemoradiotherapy remains part of the standard treatment for patients with locally advanced rectal cancer. Subsequent treatment individualization requires accurate prediction of tumor response to chemoradiotherapy. Three-dimensional endorectal ultrasound (3D-ERUS) can automatically capture and store the images of the rectal wall and rectal cancer with high resolution. In this study, we aimed to assess the correlation and predictive value between tumor volume changes measured on 3D-ERUS and the histopathological tumor response after chemoradiotherapy for patients with locally advanced rectal cancer.
A total of 54 patients with locally advanced rectal cancer who underwent chemoradiotherapy and had complete 3D-ERUS data pre-and post-chemoradiotherapy were enrolled in the study. The tumor volume pre-and post-chemoradiotherapy was measured manually on 3D-ERUS, and the tumor volume reduction ratio was calculated. The histopathological tumor regression grade (TRG) was used to assess tumor response. The differences in volumetry parameters were compared between groups with varying tumor response. The diagnostic efficacy of the tumor volume reduction ratio was evaluated by the receiver operating characteristic (ROC) curve.
The mean age of all patients was 55.19±12.46 years. The relative proportions of TRG 0-3 were 29.6% (16/54), 16.6% (9/54), 50% (27/54), and 3.8% (2/54), respectively. The median tumor volumes post-chemoradiotherapy in good responders (TRG 0-1, median tumor volume =3.26 cm) and the complete response group (TRG 0, median tumor volume =2.61 cm) were smaller than those in poor responders (TRG 2-3, median tumor volume =5.43 cm) and the partial response group (TRG 1-3, median tumor volume =4.00 cm), while tumor volume reduction ratios were higher than those of poor responders (79.32% 59.67%) and the partial response group (82.22% 61.64%), with significant differences (all P values <0.05). The ROC curves showed that the cut-off values of the tumor volume reduction ratio to predict good responders and complete response were 67.77% and 72.02%, respectively. The corresponding areas under the curve in the prediction of good responders and complete response were 0.830 and 0.829, respectively.
The tumor volume reduction ratio measured on 3D-ERUS might be a helpful indicator for tumor response in patients with locally advanced rectal cancer.
术前放化疗仍是局部晚期直肠癌患者标准治疗方案的一部分。后续治疗个体化需要准确预测肿瘤对放化疗的反应。三维直肠内超声（3D-ERUS）能够自动高分辨率采集并存储直肠壁及直肠癌的图像。在本研究中，我们旨在评估3D-ERUS测量的肿瘤体积变化与局部晚期直肠癌患者放化疗后组织病理学肿瘤反应之间的相关性及预测价值。
本研究共纳入54例接受放化疗且放化疗前后均有完整3D-ERUS数据的局部晚期直肠癌患者。在3D-ERUS上手动测量放化疗前后的肿瘤体积，并计算肿瘤体积缩小率。采用组织病理学肿瘤退缩分级（TRG）评估肿瘤反应。比较不同肿瘤反应组之间容积参数的差异。通过受试者工作特征（ROC）曲线评估肿瘤体积缩小率的诊断效能。
所有患者的平均年龄为55.19±12.46岁。TRG 0-3的相对比例分别为29.6%（16/54）、16.6%（9/54）、50%（27/54）和3.8%（2/54）。放化疗后，反应良好组（TRG 0-1，中位肿瘤体积=3.26 cm）和完全缓解组（TRG 0，中位肿瘤体积=2.61 cm）的中位肿瘤体积小于反应较差组（TRG 2-3，中位肿瘤体积=5.43 cm）和部分缓解组（TRG 1-3，中位肿瘤体积=4.00 cm），而肿瘤体积缩小率高于反应较差组（79.32%对59.67%）和部分缓解组（82.22%对61.64%），差异有统计学意义（所有P值<0.05）。ROC曲线显示，预测反应良好和完全缓解的肿瘤体积缩小率的截断值分别为67.77%和72.02%。预测反应良好和完全缓解时相应的曲线下面积分别为0.830和0.829。
3D-ERUS测量的肿瘤体积缩小率可能是局部晚期直肠癌患者肿瘤反应的一个有用指标。
