Diffusion kurtosis MRI as a predictive biomarker of response to neoadjuvant chemotherapy in high grade serous ovarian cancer

This study assessed the feasibility of using diffusion kurtosis imaging (DKI) as a measure of tissue heterogeneity and proliferation to predict the response of high grade serous ovarian cancer (HGSOC) to neoadjuvant chemotherapy (NACT). Seventeen patients with HGSOC were imaged at 3 T and had biopsy samples taken prior to any treatment. The patients were divided into two groups: responders and non-responders based on Response Evaluation Criteria In Solid Tumours (RECIST) criteria. The following imaging metrics were calculated: apparent diffusion coefficient (ADC), apparent diffusion (D(app)) and apparent kurtosis (K(app)). Tumour cellularity and proliferation were quantified using histology and Ki-67 immunohistochemistry. Mean K(app) before therapy was higher in responders compared to non-responders: 0.69 ± 0.13 versus 0.51 ± 0.11 respectively, P = 0.02. Tumour cellularity correlated positively with K(app) (rho = 0.50, P = 0.04) and negatively with both ADC (rho = −0.72, P = 0.001) and D(app) (rho = −0.80, P < 0.001). Ki-67 expression correlated with K(app) (rho = 0.53, P = 0.03) but not with ADC or D(app). In conclusion, K(app) was found to be a potential predictive biomarker of NACT response in HGSOC, which suggests that DKI is a promising clinical tool for use oncology and radiology that should be evaluated further in future larger studies.