Veneto Institute of Oncology IOV-IRCCS, via Gattamelata 64, 35128 Padua, Italy.
Eur J Radiol. 2012 Dec;81(12):3918-24. doi: 10.1016/j.ejrad.2012.04.038. Epub 2012 Aug 16.
The aim of this study was to compare volume measurements on computed tomography (CT) images with histopathological assessments of chemoradiotherapy (CRT)-induced tumor regression in locally advanced rectal cancer (RC).
In 25 patients (13 males, 12 females; median age, 63 years; age range, 44-79 years) with locally advanced RC treated with preoperative CRT and surgery, two radiologists measured tumor volume on CT images before and after CRT. CT-based tumor volumetry and the modified response evaluation criteria in solid tumors (mRECISTs) were compared with T and N downstaging after CRT, and with the tumor regression grade (TRG).
Tumor volumes were significantly smaller on CT images after CRT. The tumors regressed in 52% (13/25), 36% (9/25) and 40% (10/25) of patients, based on T downstaging, TRG and mRECIST findings, respectively. In terms of T downstaging, the pre- and post-CRT tumor volumes of responders and non-responders to the treatment differed statistically, while their tumor volume reduction rates and volume reductions according to the 65% mRECIST threshold did not. In terms of N downstaging and TRG, the differences between the responders' and the non-responders' pre- and post-CRT tumor volumes, tumor volume reduction rates, and mRECIST thresholds were never statistically significant.
Measuring tumor size on CT images is of limited value in predicting the histopathological response to preoperative CRT in RC patients, so it may be unwise to select surgical treatment strategies based on CT volumetry.
本研究旨在比较计算机断层扫描（CT）图像上的体积测量与局部晚期直肠癌（RC）放化疗（CRT）诱导的肿瘤退缩的组织病理学评估。
在 25 例接受术前 CRT 和手术治疗的局部晚期 RC 患者（13 名男性，12 名女性；中位年龄 63 岁；年龄范围 44-79 岁）中，两名放射科医生在 CRT 前后测量 CT 图像上的肿瘤体积。比较 CT 肿瘤体积测量值和改良实体瘤反应评估标准（mRECIST）与 CRT 后 T 和 N 分期降低以及肿瘤退缩分级（TRG）。
CRT 后 CT 图像上的肿瘤体积明显缩小。根据 T 分期、TRG 和 mRECIST 发现，52%（13/25）、36%（9/25）和 40%（10/25）的患者肿瘤消退。在 T 分期方面，治疗反应者和无反应者的 CRT 前后肿瘤体积存在统计学差异，而其肿瘤体积减少率和根据 65%mRECIST 阈值的体积减少则无统计学差异。在 N 分期和 TRG 方面，反应者和无反应者的 CRT 前后肿瘤体积、肿瘤体积减少率和 mRECIST 阈值之间的差异从未具有统计学意义。
在预测 RC 患者术前 CRT 的组织病理学反应方面，CT 图像上测量肿瘤大小的价值有限，因此根据 CT 体积测量值选择手术治疗策略可能不明智。
