Staging of squamous cell carcinoma of the oral cavity and oropharynx: a comparison of MRI and CT in T- and N-staging.

PURPOSE

Our purpose was to assess the accuracy of CT and MRI in staging of squamous cell carcinoma (SCC) of the oral cavity and oropharynx.

METHOD

Fifty-one episodes of primary and recurrent SCC were assessed with CT and MRI. The results were compared with pathological staging.

RESULTS

For staging primary tumours, the accuracy of MR was 77% and that of CT was 67%. For detecting recurrent tumour, the accuracy of MR was 89% and that of CT was 100%. For N-staging, nodal sites were divided, according to the site of the primary tumour, into high and low risk. Sensitivity for high risk sites was 60% for clinical assessment, 35% for CT, and 75% for MR. Negative predictive value (NPV) was < or = 50% for all methods. For low risk sites, the NPV was > or = 95% for all methods.

CONCLUSION

For T-staging, MR scanning is overall more accurate than CT. If degraded images and T1 tumours are excluded, the techniques are comparable. MR scanning is oversensitive for recurrent disease. For N-staging, all methods failed to detect small metastatic deposits.