Objective: To explore the reliability and feasibility of blood oxygenation level-dependent-based functional magnetic resonance imaging (BOLD-fMRI) to depict hypoxia in breast invasive ductal carcinoma.
Methods: A total of 103 women with 104 invasive ductal carcinomas (IDCs) underwent breast BOLD-fMRI at 3.0 T. Histological specimens were analysed for tumour size, grade, axillary lymph nodes and expression of oestrogen receptors, progesterone receptors, human epidermal growth factor receptor 2, p53, Ki-67 and hypoxia inducible factor 1α (HIF-1α). The distribution and reliability of R2* were analysed. Correlations of the R2* value with the prognostic factors and HIF-1α were respectively analysed.
Results: The R2* map of IDC demonstrated a relatively heterogeneous signal. The mean R2* value was (53.4 ± 18.2) Hz. The Shapiro-Wilk test (W = 0.971, P = 0.020) suggested that the sample did not follow a normal distribution. The inter-rater and intrarater correlation coefficient was 0.967 and 0.959, respectively. The R2* values of IDCs were significantly lower in patients without axillary lymph nodes metastasis. The R2* value had a weak correlation with Ki67 expression (r = 0.208, P = 0.038). The mean R2* value correlated moderately with the level of HIF-1α (r = 0.516, P = 0.000).
Conclusion: BOLD-fMRI is a simple and non-invasive technique that yields hypoxia information on breast invasive ductal carcinomas.