Preoperative staging MRI for rectal cancer and pathologic correlation

Abstract

Background. Our aim is to asses the accuracy of MRI for preoperative rectal cancer staging and to establish a histopathologic correlation. Methods and materials. A retrospective analysis was performed on 120 patients aged between 43 and 87 with histologically proven rectal cancer who underwent MRI for preoperative staging in our hospital between 2005 and 2010. Patients were categorized according to the TNM classification. Results. Eighty of 120 patients underwent adjuvant chemoradiotheraphy because they had advanced disease (T3-T4), lymph node involvement (N1-N2) or resectable metastases. With 40 patients who didn’t undergo neoadjuvant therapy we performed a correlation between MRI and histopathological findings with a diagnostic accuracy in predicting T stage of 72%, N stage of 60% and distance to the mesorectal fascia of 87,5%. Conclusion. Pelvic MRI is a useful technique for locoregional staging of rectal cancer with a good radiopathologic correlation although the identification of nodal disease is still a diagnostic problem.