Impact of pelvic MRI in routine clinical practice on staging of IB1-IIA2 cervical cancer

Purpose: To evaluate the impact of pelvic magnetic resonance imaging (MRI) on staging of IB1-IIA2 cervical cancer in routine clinical practice. Patients and Methods: A total of 1,016 patients with IB1-IIA2 cervical cancer who underwent primary surgery and preoperative pelvic MRI between January 2009 and December 2015 were identified in a retrospective multicentre study. Data on clinical stage, MRI reports and surgicopathologic findings were extracted from medical records. The impact of MRI on clinical staging was evaluated by comparison before and after combination of MRI. Using surgicopathologic findings as the reference standard, the impact of pelvic MRI on the accuracy of clinical staging was evaluated. Furthermore, the impact on the accuracy of individual staging parameters such as maximal tumor diameter, vaginal involvement or parametrial infiltration were also evaluated. Results: After combination of pelvic MRI, clinical stage remained unchanged in 59.7%, upstaged in 17.2%, and downstaged in 23.0% of the patients. The overall accuracy of clinical staging increased from 61.0% to 81.4% in our study (P<0.05). As for individual staging parameters, the area under the curve (AUC) for maximal tumor diameter increased from 0.58 to 0.81 (P<0.05). However, the AUC for vaginal involvement decreased from 0.61 to 0.57 (P>0.05). The AUC for parametrial infiltration was also suboptimal (AUC=0.56, P<0.05). Conclusion: In routine clinical practice, MRI could increase the overall accuracy of clinical staging in IB1-IIA2 cervical cancer. For staging parameters, it only significantly increased the accuracy of maximal tumor diameter.