Utility of Quantitative Parameters From Triple-Phase Contrast Enhanced Dual-Energy CT for Predicting Immunohistochemical Biomarkers in Invasive Breast Cancer.

[PURPOSE] To investigate the value of quantitative parameters derived from triple-phase dual-energy CT (DECT) for the discrimination of immunohistochemical biomarkers in invasive breast cancer.

[MATERIAL AND METHODS] From March 2022 to May 2023, 41 participants with breast cancer who underwent contrast enhanced (arterial, venous, and equilibrium phase) chest DECT were enrolled in this prospective study. DECT quantitative parameters were measured and compared with the immunohistochemical biomarkers [oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2)] status. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of parameters.

[RESULTS] Arterial enhancement fraction (AEF) was significantly higher in the ER-negative group than in the ER-positive group (p = 0.030) with an AUC of 0.786. AEF was identified as an independent predictor for distinguishing PR-negative from PR-positive tumours (AUC = 0.857; OR = 1/e, 95% CI: 0.000-0.205, p = 0.021). Enhancement ratio between venous phase and equilibrium phase (ERVE) was significantly higher in the HER2-positive group in contrast to the HER2-negative group (p = 0.037) with an AUC of 0.781.

[CONCLUSIONS] Triple-phase DECT-derived parameter AEF was identified as a useful negativity predictor for ER and PR levels, while ERVE was demonstrated as a positivity predictor of HER2 status in invasive breast cancer.