Background: Colorectal cancer is widely distributed. It is considered the third most common cancer worldwide. Despite performing potentially curative operations 25% to 40% develop tumor recurrence. The optimal strategy to detect recurrences at the earliest stage remains controverse. The aim of this study is to assess recto-sigmoid cancer local recurrence in patients with elevated CEA by contrast enhanced CT and contrast enhanced MRI and compare between both modalities.
Methods: This study was carried out on 24 patients who underwent surgical excision of primary recto-sigmoid cancer and under post-operative follow up with elevated CEA level. CT and MRI were done, and the results were compared.
Results: Our study included 24 their age's ranged from 23-76 years with the mean age 53 years. Twenty cases (83%) were confirmed to have recurrence while 4 cases elevated CEA levels were considered false positive. CT accuracy (79%), sensitivity (100%) and specificity (55%). These results were not as high as those of MR imaging where MRI accuracy (96%), sensitivity (100%) and specificity (91%). By using chi square test, there was no significant difference between CT and MRI in detection and assessment of locally recurrent recto sigmoid cancer patients with P value 0.3843.
Conclusion: MRI has higher specificity than CT in determining pelvic recurrence recto-sigmoid cancer in patients with elevated CEA level. It can differentiate recurrent masses from post-operative scar tissue and determine preciously the site and type of local recurrence. However, CT is mandatory in these patients as a screening modality and follow up.