Oscillating Gradient Diffusion‐Weighted MRI for Risk Stratification of Uterine Endometrial Cancer

Abstract

BackgroundOscillating gradient diffusion‐weighted imaging (DWI) enables elucidation of microstructural characteristics in cancers; however, there are limited data to evaluate its utility in patients with endometrial cancer.PurposeTo investigate the utility of oscillating gradient DWI for risk stratification in patients with uterine endometrial cancer compared with conventional pulsed gradient DWI.Study TypeRetrospective.SubjectsSixty‐three women (mean age: 58 [range: 32–85] years) with endometrial cancer.Field Strength/Sequence3 T MRI including DWI using oscillating gradient spin‐echo (OGSE) and pulsed gradient spin‐echo (PGSE) research sequences.AssessmentMean value of the apparent diffusion coefficient (ADC) values for OGSE (ADCOGSE) and PGSE (ADCPGSE) as well as the ADC ratio (ADCOGSE/ADCPGSE) within endometrial cancer were measured using regions of interest. Prognostic factors (histological grade, deep myometrial invasion, lymphovascular invasion, International Federation of Gynecology and Obstetrics [FIGO] stage, and prognostic risk classification) were tabulated.Statistical TestsInterobserver agreement was analyzed by calculating the intraclass correlation coefficient. The associations of ADCOGSE, ADCPGSE, and ADCOGSE/ADCPGSE with prognostic factors were examined using the Kendall rank correlation coefficient, Mann–Whitney U test, and receiver operating characteristic (ROC) curve. A P value of <0.05 was statistically significant.ResultsCompared with ADCOGSE and ADCPGSE, ADCOGSE/ADCPGSE was significantly and strongly correlated with histological grade (observer 1, τ = 0.563; observer 2, τ = 0.456), FIGO stage (observer 1, τ = 0.354; observer 2, τ = 0.324), and prognostic risk classification (observer 1, τ = 0.456; observer 2, τ = 0.385). The area under the ROC curves of ADCOGSE/ADCPGSE for histological grade (observer 1, 0.92, 95% confidence intervals [CIs]: 0.83–0.98; observer 2, 0.84, 95% CI: 0.73–0.92) and prognostic risk (observer 1, 0.80, 95% CI: 0.68–0.89; observer 2, 0.76, 95% CI: 0.63–0.86) were significantly higher than that of ADCOGSE and ADCPGSE.Data ConclusionThe ADC ratio obtained via oscillating gradient and pulsed gradient DWIs might be useful imaging biomarkers for risk stratification in patients with endometrial cancer.Level of Evidence3Technical EfficacyStage 2