Routine follow-up by magnetic resonance imaging does not improve detection of resectable local recurrences from colorectal cancer

OBJECTIVE: To determine if routine follow-up by magnetic resonance imaging (MRI) improves the detection of resectable local recurrences from colorectal cancer. SUMMARY BACKGROUND DATA: Surgical treatment offers the best prospect of survival for patients with recurrent colorectal cancer. Unfortunately, most cases are often diagnosed at an unresectable stage when traditional follow-up methods are used. The impact of MRI surveillance on the early diagnosis of local recurrences has yet to be ascertained. METHODS: Patients who underwent curative surgery for rectal and left-sided colon tumors were included in a program of pelvic surveillance by routine MRI, in addition to the standard follow-up protocol. Cases were then analyzed for mode of diagnosis, resectability, and overall survival. RESULTS: Pelvic recurrence was found in 30 (13%) of the 226 patients studied. MRI detected 26 of 30 (87%) and missed 4 of 30 (13%) cases with local recurrence. Of the latter, 3 were anastomotic recurrences. In 28 (14%) patients, local recurrence was suspected by an initial MR scan but cleared by subsequent MRI or CT-guided biopsy. Recurrent pelvic cancer was diagnosed by MRI with 87% sensitivity and 86% specificity. In 19 (63%) cases, CEA was abnormally elevated, and 9 patients (30%) were symptomatic. Surgical resection was possible in only 6 patients (20%). There was no difference between MRI and conventional follow-up tests in their ability to detect cases suitable for surgery. CONCLUSIONS: Pelvic surveillance by MRI is not justified as part of the routine follow-up after a curative resection for colorectal cancer and should be reserved for selectively imaging patients with clinical, colonoscopic, and/or biochemical suspicion of recurrent disease.