Parametrial evaluation in cervical cancer by magnetic resonance imaging and clinical examination: Analysis of data from the prospective Leipzig School MMR study.

Abstract

5525 Parametrial evaluation in cervical cancer by magnetic resonance imaging and clinical examination Background: In cervical cancer patients, assessment of parametrial tumor extension is important for staging and treatment planning. The 2019 cervical cancer guideline published by the Féderation Internationale de Gynécologie et d’Obstétrique (FIGO) for the first time includes recommendations for usage of magnetic resonance imaging (MRI) in this setting. However, valid data regarding the accuracy of this method, especially in patients with advanced disease, are sparce. The objective of this investigation was to compare the accuracy of parametrial assessment in cervical cancer patients using MRI and clinical examination under general anesthesia. Methods: A retrospective cohort study based on data from the prospective monocentric observational Leipzig School Mesometrial Resection study was conducted. Cervical cancer patients staged FIGO IB1 to FIGO IVA who underwent primary surgery between 1999 and 2017 were included. Data from pathological specimen of these patients was compared to the MRI findings and the results from clinical examination under general anesthesia. The gynecological oncologist had access to the MR images during clinical assessment. We calculated sensitivities, specificities, and predictive values for both examination methods. We performed logistic regression modelling to determine factors influencing the accuracy of either method. Results: 400 women were included. Pathologically proven parametrial tumor invasion was present in 165 (41%) patients. Examination under anesthesia augmented by intraoperative display of MR images exhibited a higher accuracy (83%) as compared to MRI alone (76%; McNemar’s odds ratio = 2.0, 95%CI 1.25 – 3.27, p = 0.003). While accuracy was not affected by tumor size in clinical examination, MRI was associated with a significant drop in accuracy in tumors ≥ 2.5 cm (univariable logistic regression, OR for a correct diagnosis compared to smaller tumors 0.22, p < 0.001). This association remained significant in a multivariable model. There was also a significant decrease in specificity when evaluating parametrial invasion by MRI in tumors ≥ 2.5 cm in diameter (p < 0.0001). Body mass index had no influence on performance of either method. Accuracy was significantly higher when test results were concordant (OR 7.5 and 6.0 on univariable and multivariable regression modelling, respectively, p < 0.0001 in both cases). Conclusions: Clinical evaluation of the parametrium by pelvic examination under anesthesia in conjunction with intraoperative presentation of MR images leads to more accurate staging in cervical cancer patients as compared to magnetic resonance imaging alone. Clinical examination should therefore remain an integral part of parametrial assessment in cervical cancer patients.