Endometrial Cancer Staging: Is There Value in ADC?

Abstract

Purpose: To assess the ability of apparent diffusion coefficient (ADC) measurements in predicting the histological grade of endometrial cancer. A secondary goal was to assess the agreement between MRI and surgical staging as an accurate measurement.

Methods: Patients with endometrial cancers diagnosed between 2018-2020 and having received both MRI and surgical staging were retrospectively enrolled. Patients were characterized according to histology, tumor size, FIGO stage (MRI and surgical stage), and functional MRI parameters (DCE and DWI/ADC). Statistical analysis was performed to determine if an association could be identified between ADC variables and histology grade. Secondarily, we assessed the degree of agreement between the MRI and surgical stages according to the FIGO classification.

Results: The cohort included 45 women with endometrial cancer. Quantitative analysis of ADC variables did not find a statistically significant association with histological tumor grades. DCE showed higher sensitivity than DWI/ADC in the assessment of myometrial invasion (85.00% versus 65.00%) with the same specificity (80.00%). A good agreement between MRI and histopathology for the FIGO stage was found (kappa of 0.72, p < 0.01). Differences in staging between MRI and surgery were detected in eight cases, which could not be justified by the interval between MRI and surgery.

Conclusions: ADC values were not useful for predicting endometrial cancer grade, despite the good agreement between MRI interpretation and histopathology of endometrial cancer staging at our center.

Keywords: apparent diffusion coefficient; diffusion-weighted imaging; dynamic contrast-enhanced magnetic resonance imaging; endometrial cancer; grading; magnetic resonance imaging; staging.

Figure 1

Sixty-year-old female staged at MRI as T1a and proven at pathology as T1a. Depiction of the method used for the quantitative data collection with the two different ROI—full lesion ROI (large circle) and focused ROI (small circle).

Figure 2

Fifty-seven-year-old female with a Mullerian malformation (septate uterus) staged at MRI as T1b and proven at pathology as T1b. The presence of a uterine malformation is a pitfall for the detection of myometrial infiltration by the tumor. Depiction of the method used for the quantitative data collection with the two different ROI.

Figure 3

Seventy-year-old female with a leiomyoma staged at MRI as T1a and proven at pathology to be a T1a. Leiomyomas are one of the pitfalls for the determination of myometrial invasion by tumor. Depiction of the method used for the quantitative data collection using the two different ROI.