Preoperative Magnetic Resonance Imaging versus Intraoperative Frozen Section Diagnosis for Predicting the Deep Myometrial Invasion in Endometrial Cancer: Our Experience and Literature Review

Abstract

Aim: The present study was designed to directly compare the diagnostic performance of preoperative magnetic resonance imaging (MRI) and intraoperative frozen section (FS) diagnoses in predicting deep myometrial invasion (MI) of endometrial cancer. Methods: Using MRI findings and FS diagnoses, 194 patients with surgically staged endometrial cancer were evaluated for deep MI between 2006 and 2018. Definitive histological diagnosis of paraffin sections of excised tissues was used as the gold standard approach. Results: Of 194 cases, 53 (27.3%) cases were finally diagnosed as having deep MI (≥50%). There was 82% total agreement between MRI and FS diagnoses in predicting deep MI, with a kappa value of 0.54 (95% confidence interval [CI] = 0.40-0.67, moderate agreement). The sensitivity of FS diagnosis (0.66, 95% CI = 0.52-0.78) for predicting deep MI was lower than that of MRI (0.77, 95% CI = 0.63-0.87; p = 0.21), while the specificity of FS (0.98, 95% CI = 0.93-0.99) was significantly higher than that of MRI (0.88, 95% CI = 0.81-0.93; p = 0.001). Overall, the accuracy of FS (0.89, 95% CI = 0.84-0.93) was higher than that of MRI (0.85, 95% CI = 0.79-0.90), although the difference did not reach statistical significance (p = 0.23). The accuracy (0.95, 95% CI = 0.90-0.97) was very high in cases with concordant MRI and FS results. Conclusions: MRI and FS showed different diagnostic characteristics for predicting deep MI, with a higher specificity observed for FS and the greatest accuracy obtained in concordant cases. Thus, our findings recommend the addition of FS diagnosis, either alone or in conjunction with MRI, to MI evaluation.

Evaluation of the role of intraoperative frozen section and magnetic resonance imaging in endometrial cancer

“…Further, specificity of intraoperative diagnosis was higher than that of preoperative biopsy when there was no myometrial invasion. While Iitsuka et al 23 suggested the efficacy of both MRI and intraoperative diagnosis especially focusing on cases with more than 1/2 myometrial invasion, our study suggests that intraoperative diagnosis is also useful in cases with none or less than 1/2 myometrial invasion. The concordance rate was expected to increase as the number of sections increased.…”

“…Further, specificity of intraoperative diagnosis was higher than that of preoperative biopsy when there was no myometrial invasion. While Iitsuka et al 23 was expected to increase as the number of sections increased.…”

Efficacy of transvaginal ultrasound versus magnetic resonance imaging for preoperative assessment of myometrial invasion in patients with endometrioid endometrial cancer: a prospective comparative study

“…3,15,20 Iitsuka et al in their study and review of literature found that their data and the pooled analysis with previous studies indicate that the frozen section diagnosis is sensitive as MRI assessment in predicting deep MI, and has a higher specificity compared with MRI. 27 Contraindications for MRI should also be kept in mind, when MRI cannot be performed such as metal foreign body, pathologic obesity, contrast allergies and claustrophobia.…”

“…in their study and review of literature found that their data and the pooled analysis with previous studies indicate that the frozen section diagnosis is sensitive as MRI assessment in predicting deep MI, and has a higher specificity compared with MRI. 27 …”

Analysis of vanishing endometrial cancer by pathological types

“…Preoperative MRI reveals myometrial invasion almost as accurately as examination of frozen sections. 18 In patients with endometrioid-type grade 1 EC, the risk of myometrial invasion evident in the postoperative hysterectomy specimen is less than 1% if such invasion has not been detected by MRI. 19 Therefore, the specificity of MRI is high in such cases.…”