OBJECTIVE: To compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) in the preoperative assessment of early-stage cervical cancer using pathologic findings as the reference standard.
PATIENTS AND METHODS: Prospective multi-center trial enrolling 209 consecutive women with early-stage cervical cancer (FIGO IA2-IIA) scheduled for surgery. The following parameters were assessed on US and MRI and compared to pathology: remaining tumor, size, tumor stromal invasion<2/3 (superficial) or ≥2/3 (deep), and parametrial invasion.
RESULTS: Complete data were available for 182 patients. The agreement between US and pathology was excellent for detecting tumors, correctly classifying bulky tumors (>4cm), and detecting deep stromal invasion (kappa values 0.84, 0.82, and 0.81 respectively); and good for classifying small tumors (<2cm) and detecting parametrial invasion (kappa values 0.78 and 0.75, respectively). The agreement between MRI and histology was good for classifying tumors as <2cm, or >4cm, and detecting deep stromal invasion (kappa values 0.71, 0.76, and 0.77, respectively). It was moderately accurate in tumor detection, and in assessing parametrial invasion (kappa values 0.52 and 0.45, respectively). The agreement between histology and US was significantly better in assessing residual tumor (p<0.001) and parametrial invasion (p<0.001) than the results obtained by MRI. Imaging methods were not significantly influenced by previous cone biopsy.
CONCLUSION: US and MRI are highly accurate for the preoperative assessment of women with early-stage cervical cancer, although US may be more accurate in detecting residual tumors and assessing parametrial invasion.