Evaluation of parametrial status in locally advanced cervical cancer patients after neoadjuvant chemotherapy: a prospective study on diagnostic accuracy of three-dimensional transvaginal ultrasound

To analyze the diagnostic accuracy of two-dimensional (2D) and three-dimensional transvaginal ultrasound (3D TV-US) for evaluation of parametrial status in locally advanced cervical cancer patients after neoadjuvant chemotherapy (NACT), using histology as the gold standard. Methods: Consecutive patients with histologically confirmed cervical cancer were staged according to FIGO (International Federation of Gynaecology and Obstetrics) criteria. All IB2-IIIB FIGO stage patients were examined by 2D and 3D TV-US and magnetic resonance imaging (MRI) at the diagnosis time (T0) and after NACT. At T0, the US evaluation of parametrial involvement was compared to MRI before treatment. The results of US and MRI examinations of parametrial status after NACT were compared with the histological specimen. Results: We enroled 51 consecutive patients in the study. Before chemotherapy, clinical examination under anaesthesia identified parametrial involvement in 48 patients, ultrasonography in 46 patients, and MRI in 49 patients. The agreement between US and MRI was 94%. The sensitivity of US for parametrial status was 93.8%, with a positive predictive value of 97.8%, using MRI as the standard. The correlation between US and MRI was statistically significant (p = 0). After chemotherapy, histological examination of surgical specimens identified parametrial involvement in 3 patients. Ultrasonography correctly identified those cases with parametrial infiltration, recording a sensitivity of 100%, specificity of 90.9%, positive predictive value of 50%, and negative predictive value of 100%. The MRI had a sensitivity of 100%, specificity of 45.5%, positive predictive value of 14.3%, and negative predictive value of 100%, respectively. The concordance in the identification of the presence/absence of infiltration between US and MRI with histology was 90% (p = 0.001) and 61%, respectively, after chemotherapy treatment. Particularly, in defining the degree of infiltration, the agreement between US and MRI with histology was 90 and 58%, respectively. Conclusion: In locally advanced cervical cancer patients, 2D/3D TV-US can be considered accurate in the evaluation of parametrial infiltration to assess the response to NACT. It could be included as a diagnostic method in the preoperative work-up of cervical cancer.