Reliability of magnetic resonance imaging for bladder or rectum invasion in cervical cancer

To find out whether a negative finding on magnetic resonance imaging (MRI) can rule out bladder or rectum mucosal invasion safely without cystoscopy or sigmoidoscopy.

We retrospectively reviewed the medical records of patients with cervical cancer between January 2005 and December 2009. MRI findings on bladder or rectum were classified as follows: (1) definite evidence of mucosal invasion, (2) suggestive of mucosal invasion or (3) no evidence of mucosal invasion. We correlated MRI findings with the cystoscopy and sigmoidoscopy findings.

A total of 257 patients were enrolled in this study. Sixteen patients had at least suspicious bladder invasion, and 1 patient had definite rectal invasion on MRI. Of these 17 patients, 6 patients had actual bladder mucosa invasion, and 1 patient had rectal mucosa invasion. The remaining 240 had negative MRI, cystoscopy and sigmoidoscopy findings. The MRI sensitivity, specificity, positive predictive value, negative predictive value and accuracy of bladder or rectum mucosal invasion were 100%, 96.0%, 41.25%, 100% and 96.1%, respectively.

Skipping cystoscopy or sigmoidoscopy based on the absence of invasion on MRI is safe enough without concern for understaging.