Can radicality of surgery be safely modulated on the basis of MRI and PET/CT imaging in locally advanced cervical cancer patients administered preoperative treatment?

BACKGROUND: The goal of this study was to prospectively analyze the diagnostic performances of magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT) in predicting pathologically assessed residual disease in a large, single-institution series of locally advanced cervical cancer (LACC) patients triaged to neoadjuvant treatments followed by radical surgery. METHODS: Between April 2007 and March 2010, 96 patients with histologically documented cervical cancer (any histology) and FIGO stage IB2-IVA were enrolled. MRI and PET/CT were recommended to be performed within 4-6 weeks from the end of treatment, and histology was the reference standard. Sensitivity, specificity, and accuracy were compared using the McNemar test. RESULTS: For residual disease in the cervix, sensitivity was higher for MRI than for PET/CT (86.1% vs 63.1%; P = .002), while specificity was significantly higher for PET/CT compared with MRI (P = .002). There was no difference in accuracy values between the 2 imaging modalities. For MRI analysis of lymph node groups, sensitivity, specificity, and accuracy were 35.7%, 95.9%, and 88.0%, respectively. Conversely, sensitivity, specificity, and accuracy for PET/CT were 28.6%, 97.8%, and 88.7%, respectively. Absence of follicular structures replaced by prevalent sclerosis and/or sinus histiocytosis was the most frequently documented morphological pattern in false-positive cases. CONCLUSION: Neither MRI nor PET/CT accurately detected residual disease in LACC patients triaged to radical surgery after neoadjuvant treatment, disallowing the option of avoiding or modulating completion surgery.