Suppiah A, Hunter I A, Cowley J, Garimella V, Cast J, Hartley J E, Monson J R T
Academic Surgical Unit, Castle Hill Hospital, Cottingham, East Yorkshire, United Kingdom.
Colorectal Dis. 2009 Mar;11(3):249-53. doi: 10.1111/j.1463-1318.2008.01593.x. Epub 2008 May 29.
Magnetic resonance imaging (MRI) is increasingly accepted as the radiological modality of choice staging rectal cancer but is subject to error. Neoadjuvant therapy is increasingly used in rectal cancer and MRI is used to stage response and occasionally plan surgery. We aim to assess the staging accuracy of MRI following chemoradiotherapy in rectal cancer.
Retrospective analysis of 86 patients with MRI stage pre- and postlong-course chemoradiotherapy and comparison with pathological assessment.
Fourty-nine patients (34 men, 15 women) with median age 68 years (60-74) were analysed. The median time from completion of CRT to MRI was 32 days (16-37). Chemoradiotherapy led to significant down-staging (P < 0.001). MRI-staging accuracy was 43% (21/49) with over- and under-staging in 43% (21/49) and 14% (7/49) respectively. T-stage accuracy was 45% (22/49) with over-staging in 33% (16/49) and under-staging in 22% (11/49). MRI stage correlated poorly with pathological assessment for International Union Against Cancer (kappa = 0.255) and T stages (kappa = 0.112). MRI nodal assessment was 71% (35/49) accurate, with 82% (9/11) sensitivity, 68% (26/38) specificity and positive predictive value (PPV) of 43% (9/21) and negative predictive value of 93% (26/28). There was a significant difference in node positivity between MRI and pathological staging (P = 0.005, Fisher's exact). Complete radiological response was observed in 4% (2/49). Complete pathological response was observed in 10% (5/49), which were staged 0(1), I(1), II(2) and III(1) postchemoradiotherapy by MRI.
MRI staging following chemoradiation is poor. Over-staging occurs three times more commonly than under-staging. Over-staging is due to poor PPV of nodal assessment.
磁共振成像（MRI）越来越被认为是直肠癌分期的首选影像学检查方法，但仍存在误差。新辅助治疗在直肠癌中的应用越来越广泛，MRI用于评估治疗反应，偶尔也用于手术规划。我们旨在评估直肠癌放化疗后MRI的分期准确性。
回顾性分析86例患者放化疗前后的MRI分期，并与病理评估结果进行比较。
分析了49例患者（34例男性，15例女性），中位年龄68岁（60 - 74岁）。从放化疗结束到进行MRI检查的中位时间为32天（16 - 37天）。放化疗导致分期显著降低（P < 0.001）。MRI分期准确性为43%（21/49），分期过高和过低的分别占43%（21/49）和14%（7/49）。T分期准确性为45%（22/49），分期过高的占33%（16/49），分期过低的占22%（11/49）。MRI分期与国际抗癌联盟的病理评估（kappa = 0.255）及T分期（kappa = 0.112）相关性较差。MRI对淋巴结的评估准确率为71%（35/49），敏感性为82%（9/11），特异性为68%（26/38），阳性预测值（PPV）为43%（9/21），阴性预测值为93%（26/28）。MRI与病理分期在淋巴结阳性方面存在显著差异（P = 0.005，Fisher精确检验）。4%（2/49）观察到完全放射学缓解。10%（5/49）观察到完全病理缓解，MRI显示放化疗后这些患者分别为0期（1例）、I期（1例）、II期（2例）和III期（1例）。
放化疗后的MRI分期效果不佳。分期过高的发生率是分期过低的三倍。分期过高是由于淋巴结评估的阳性预测值较低。
