Sahlgrenska Academy, Department of Surgery, Institute of Clinical Sciences, Sahlgrenska University Hospital/Östra, 41685 Gothenburg, Sweden.
World J Gastroenterol. 2013 Jun 7;19(21):3263-71. doi: 10.3748/wjg.v19.i21.3263.
To assess the stage and size of rectal tumours using 1.5 Tesla (1.5T) magnetic resonance imaging (MRI) and three-dimensional (3D) endosonography (ERUS).
In this study, patients were recruited in a phase I/II trial of neoadjuvant chemotherapy for biopsy-proven rectal cancer planned for surgical resection with or without preoperative radiotherapy. The feasibility and accuracy of 1.5T MRI and 3D ERUS were compared with the histopathology of the fixed surgical specimen (pathology) to determine the stage and size of the rectal cancer before and after neoadjuvant chemotherapy. A Philips Intera 1.5T with a cardiac 5-channel synergy surface coil was used for the MRI, and a B-K Medical Falcon 2101 EXL 3D-Probe was used at 13 MHz for the ERUS. Our hypothesis was that the staging accuracy would be the same when using MRI, ERUS and a combination of MRI and ERUS. For the combination, MRI was chosen for the assessment of the lymph nodes, and ERUS was chosen for the assessment of perirectal tissue penetration. The stage was dichotomised into stage I and stage II or greater. The size was measured as the supero-inferior length and the maximal transaxial area of the tumour.
The staging feasibility was 37 of 37 for the MRI and 29 of 36 for the ERUS, with stenosis as a limiting factor. Complete sets of investigations were available in 18 patients for size and 23 patients for stage. The stage accuracy by MRI, ERUS and the combination of MRI and ERUS was 0.65, 0.70 and 0.74, respectively, before chemotherapy and 0.65, 0.78 and 0.83, respectively, after chemotherapy. The improvement of the post-chemotherapy staging using the combination of MRI and ERUS compared with the staging using MRI alone was significant (P = 0.046). The post-chemotherapy understaging frequency by MRI, ERUS and the combination of MRI and ERUS was 0.18, 0.14 and 0.045, respectively, and these differences were non-significant. The measurements of the supero-inferior length by ERUS compared with MRI were within 1.96 standard deviations of the difference between the methods (18 mm) for tumours smaller than 50 mm. The agreement with pathology was within 1.96 standard deviations of the difference between imaging and pathology for all tumours with MRI (15 mm) and for tumours that did not exceed 50 mm with ERUS (22 mm). Tumours exceeding 50 mm in length could not be reliably measured by ERUS due to the limit in the length of each recording.
MRI is preferable to use when assessing the size of large or stenotic rectal tumours. However, staging accuracy is improved by combining MRI with ERUS.
使用 1.5 特斯拉（1.5T）磁共振成像（MRI）和三维（3D）腔内超声（ERUS）评估直肠肿瘤的分期和大小。
在这项研究中，我们招募了一项新辅助化疗治疗活检证实的直肠癌的 I/II 期临床试验的患者，这些患者计划进行手术切除，无论是否进行术前放疗。比较 1.5T MRI 和 3D ERUS 的可行性和准确性，以确定新辅助化疗前后直肠肿瘤的分期和大小。使用飞利浦 Intera 1.5T 心脏 5 通道协同表面线圈进行 MRI，使用 B-K Medical Falcon 2101 EXL 3D-Probe 在 13 MHz 下进行 ERUS。我们的假设是，使用 MRI、ERUS 和 MRI 和 ERUS 的组合进行分期时，其准确性是相同的。对于组合，选择 MRI 评估淋巴结，选择 ERUS 评估直肠周围组织浸润。分期分为 I 期和 II 期或更高级别。大小测量为肿瘤的上下长度和最大横截面积。
MRI 的分期可行性为 37 例中的 37 例，ERUS 的分期可行性为 36 例中的 29 例，狭窄是一个限制因素。18 例患者可获得完整的大小检查，23 例患者可获得分期检查。化疗前 MRI、ERUS 和 MRI 和 ERUS 联合的分期准确性分别为 0.65、0.70 和 0.74，化疗后分别为 0.65、0.78 和 0.83。化疗后使用 MRI 和 ERUS 联合进行分期的改善与单独使用 MRI 进行分期相比具有统计学意义（P=0.046）。MRI、ERUS 和 MRI 和 ERUS 联合的化疗后过度分期频率分别为 0.18、0.14 和 0.045，这些差异无统计学意义。对于小于 50mm 的肿瘤，ERUS 测量的上下长度与 MRI 相比，在两种方法（18mm）之间的差异的 1.96 个标准差范围内。对于所有 MRI 肿瘤（15mm）和不超过 50mm 的 ERUS 肿瘤（22mm），与病理学的一致性在成像和病理学之间的差异的 1.96 个标准差范围内。由于每个记录的长度限制，长度超过 50mm 的肿瘤无法通过 ERUS 进行可靠测量。
当评估大型或狭窄直肠肿瘤的大小时，MRI 是首选。然而，通过将 MRI 与 ERUS 结合使用，可以提高分期准确性。
