Prediction of HIF-1α expression in endometrial carcinoma by enhanced T₂ ^∗ weighted angiography and dynamic contrast-enhanced magnetic resonance imaging

Purpose: To explore the value of quantitative imaging parameters by enhanced T₂ ^* weighted angiography (ESWAN) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for evaluating the expression of Hypoxia-inducible factor-1α (HIF-1α) in endometrial carcinoma (EC).

Methods: Data from 122 patients with EC confirmed by clinical pathology were retrospectively analyzed. According to the number of positive cells stained with HIF-1α by immunohistochemistry, patients were divided into two groups: 65 cases with high expression of HIF-1α and 57 cases with low expression of HIF-1α. Clinical data included age, FIGO stage, menopausal status, abnormal uterine bleeding, and pathological type. All patients underwent preoperative 1.5T MRI scans, including ESWAN and DCE-MRI. The amplitude, phase, and R₂ ^* values derived from ESWAN and the volume transfer constant (K^trans), rate constant (K_ep), and extravascular volume fraction (V_e) values derived from DCE-MRI were measured by two observers, respectively. The intra-class correlation coefficient (ICC) was used to assess the measurement of reproducibility across observers, and the differences in imaging parameters between the two groups were compared using the independent sample t-test or Mann-Whitney U-test. Binary logistic regression analysis was used to find independent risk factors for HIF-1α expression. The efficacy of selected imaging parameters for predicting HIF-1α expression was assessed using receiver operating characteristic (ROC) curves, and the Delong test was used to compare the area under ROC curves (AUC).

Results: The consistency between the two observers was good (ICC>0.75). The R₂ ^*, K^trans, and K_ep values of the HIF-1α high expression group were higher than those of the HIF-1α low expression group (14.59 ± 4.06 vs. 11.99 ± 2.84 Hz, 0.45 ± 0.18 vs. 0.36 ± 0.14/min, and 2.17 ± 1.10 vs. 1.54 ± 0.80/min) (P< 0.001, P = 0.011, and P =0.001). Binary logistic regression analysis revealed that R₂ ^* and K_ep values were independent risk factors for HIF-1α expression. The AUC values of R₂ ^*, K_ep, and their combination for prediction of HIF-1α expression were 0.697, 0.677, and 0.781, respectively. The diagnostic efficacy was significantly improved with combination of R₂ ^* and K_ep.

Conclusions: Quantitative parameters by ESWAN and DCE-MRI showed significant differences between EC patients with low and high expression of HIF-1α, and the combination of ESWAN and DCE-MRI improves the efficacy in prediction of HIF-1α expression in EC, which has an excellent clinical application prospect.