Kim N K, Kim M J, Yun S H, Sohn S K, Min J S
Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
Dis Colon Rectum. 1999 Jun;42(6):770-5. doi: 10.1007/BF02236933.
The preoperative assessment of rectal cancer wall invasion and regional lymph node metastasis is essential for the planning of optimal therapy. This study was done to determine the accuracy and clinical usefulness of transrectal ultrasonography, pelvic computed tomography, and magnetic resonance imaging in preoperative staging.
A total of 89 patients with rectal cancer were examined with transrectal ultrasonography (n = 89), pelvic computed tomography (n = 69), and magnetic resonance imaging with endorectal coil (n = 73). The results obtained by these diagnostic modalities were compared with the histopathologic staging of specimens.
In staging depth of invasion, the overall accuracy was 81.1 percent (72/89) by transrectal ultrasonography, 65.2 percent (45/ 69) by computed tomography, and 81 percent (59/73) by magnetic resonance imaging. Overstaging was 10 percent (9/89) by transrectal ultrasonography, 17.4 percent (12/69) by computed tomography, and 11 percent (8/73) by magnetic resonance imaging; and understaging was 8 of 89 (8.9 percent) by transrectal ultrasonography, 12 of 69 (17.4 percent) by computed tomography, and 6 of 73 (8 percent) by magnetic resonance imaging. In staging lymph node metastasis, the overall accuracy rate was 54 of 85 (63.5 percent) in transrectal ultrasonography, 39 of 69 (56.5 percent) in computed tomography, and 46 of 73 (63 percent) in magnetic resonance imaging. The sensitivity was 24 of 45 (53.3 percent) in transrectal ultrasonography, 14 of 25 (56 percent) in computed tomography, and 33 of 42 (78.5 percent) in magnetic resonance imaging; and specificity was 30 of 40 (75.0 percent) in transrectal ultrasonography, 25 of 44 (56.8 percent) in computed tomography, and 13 of 31 (41.9 percent) in magnetic resonance imaging. The accuracy in detection of positive lateral pelvic lymph nodes under magnetic resonance imaging (n = 8) was 12.5 percent. The accuracy in detection of posterior vaginal wall invasion was 100 percent in transrectal ultrasonography (n = 7) and 100 percent in magnetic resonance imaging (n = 3), but 28.5 percent in computed tomography (n = 7).
Both transrectal ultrasonography and magnetic resonance imaging with endorectal coil exhibited similar accuracy and were superior to conventional computed tomography in preoperative assessment of depth of invasion and adjacent organ invasion. Because transrectal ultrasonography is a safer and more cost-effective modality than magnetic resonance imaging, transrectal ultrasonography is an appropriate method for preoperative staging of rectal cancer. Further efforts will be needed to provide a better staging of lymph node involvement.
直肠癌壁浸润及区域淋巴结转移的术前评估对于制定最佳治疗方案至关重要。本研究旨在确定经直肠超声、盆腔计算机断层扫描及磁共振成像在术前分期中的准确性及临床实用性。
共89例直肠癌患者接受了经直肠超声检查（n = 89）、盆腔计算机断层扫描（n = 69）及直肠内线圈磁共振成像检查（n = 73）。将这些诊断方法所得结果与标本的组织病理学分期进行比较。
在浸润深度分期方面，经直肠超声的总体准确率为81.1%（72/89），计算机断层扫描为65.2%（45/69），磁共振成像为81%（59/73）。经直肠超声过度分期为10%（9/89），计算机断层扫描为17.4%（12/69），磁共振成像为11%（8/73）；经直肠超声分期不足为89例中的8例（8.9%），计算机断层扫描为69例中的12例（17.4%），磁共振成像为73例中的6例（8%）。在淋巴结转移分期方面，经直肠超声的总体准确率为85例中的54例（63.5%），计算机断层扫描为69例中的39例（56.5%），磁共振成像为73例中的46例（63%）。经直肠超声的敏感性为45例中的24例（53.3%），计算机断层扫描为25例中的14例（56%），磁共振成像为42例中的33例（78.5%）；特异性方面，经直肠超声为40例中的30例（75.0%），计算机断层扫描为44例中的25例（56.8%），磁共振成像为31例中的13例（41.9%）。磁共振成像检测盆腔外侧阳性淋巴结（n = 8）的准确率为12.5%。经直肠超声（n = 7）和磁共振成像（n = 3）检测阴道后壁浸润的准确率均为100%，但计算机断层扫描（n = 7）的准确率为28.5%。
经直肠超声和直肠内线圈磁共振成像在术前浸润深度及邻近器官浸润评估中显示出相似的准确性，且优于传统计算机断层扫描。由于经直肠超声比磁共振成像更安全且成本效益更高，因此经直肠超声是直肠癌术前分期的合适方法。还需要进一步努力以更好地对淋巴结受累情况进行分期。
