Session Item

The staging of endometrial carcinoma (EC) is surgical but magnetic resonance imaging (MRI) is the most important imaging method to establish pre-surgical staging, which allows surgical treatment planning. It is a highly specific technique for diagnosing the depth of myometrial invasion, cervical stromal involvement, and lymph node metastases. The objective of this study is to evaluate the usefulness of preoperative staging by MRI in EC in our center.

Patients diagnosed with EC in our center between 2015 and 2021 were selected. Of these, patients who underwent pre-surgical MRI for staging were analyzed. The pre-surgical FIGO MRI stage was collected, as well as the definitive anatomopathological FIGO stage. Univariate and multivariate analyzes were performed.

Of the 348 patients with EC, 206 patients (59.19%) were analyzed. 78 patients (37.8%) were classified as stage IA, 100 (48.5%) IB, 12 (5.8%) II, 13 (6.3%) III, of which 10 IIIC, and 3 patients (1.5%) stage IV. In the definitive pathological study, endometrioid histology was observed in 148 patients (71.8%) and non-endometrioid in 58; with a histological grade G1 in 34 patients (16.5%), G2 in 104 (50.48%) and G3 in 68 patients (33%). Lymphovascular invasion (LVI) was observed in 39 patients (18.9%) and the definitive FIGO classification was stage IA in 78 patients (37.9%), IB in 85 (41.3%), II in 18 (8.7%), III in 24 (11.7%) and stage IV in a single patient (0.5%).

Statistically significant differences were found between the FIGO classification assessed in the pre-surgical MRI and the definitive pathological anatomy (PA) (p=0.001). Up to 46.6% of the patients presented a stage different from that established by MRI, being in 52.6% higher in the surgical piece. An erroneous preoperative diagnosis was made in 44.87% of patients diagnosed as FIGO IA, 43% of FIGO IB, 16.6% of FIGO II, 38.46% of FIGO III, and 100% of those initially classified as FIGO IV.

No differences were found between the pre- and post-surgical classification based on histology or grade, but statistically significant differences were found in the patients who presented ILV (p=0.049).

When analyzing the sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (PPN) of the pre-surgical MRI by stages, we found that in IA it was 55.12%, 72.65%, 55.12% and 72.65%, respectively. In stage IB it was 67.05%, 64.46%, 57% and 73.58%. In stage II 11.11%, 94.68%, 16.6% and 91.7%. In FIGO III stage it was 33.3%, 97.25%, 61.53% and 91.7%. In FIGO stage IV, both sensitivity and PPV were 0% and both specificity and PPN were 98.5%.

MRI in our center plays an important role in excluding patients who do not have cervical stromal invasion as well as extrauterine infiltration or lymph node metastases, but it is necessary to improve in determining the depth of myometrial invasion.