Abstract
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 (Dapp) and apparent kurtosis (Kapp). Tumour cellularity and proliferation were quantified using histology and Ki-67 immunohistochemistry. Mean Kapp 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 Kapp (rho = 0.50, P = 0.04) and negatively with both ADC (rho = −0.72, P = 0.001) and Dapp (rho = −0.80, P < 0.001). Ki-67 expression correlated with Kapp (rho = 0.53, P = 0.03) but not with ADC or Dapp. In conclusion, Kapp 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.
Highlights
Ovarian cancer has the highest mortality of any gynaecological malignancy in the developed world
This study demonstrated that measurements of the non-Gaussian movement of water with diffusion kurtosis imaging (DKI) may predict the response to neoadjuvant chemotherapy in high grade serous ovarian cancer (HGSOC) patients
Tumours with a higher mean Kapp before the start of chemotherapy were found to respond better to treatment whereas neither conventional apparent diffusion coefficient (ADC), nor its equivalent calculated from the DKI acquisition (Dapp), could effectively differentiate responders from non-responders
Summary
Ovarian cancer has the highest mortality of any gynaecological malignancy in the developed world. The first line chemotherapy choice for HGSOC is a platinum-based drug together with a taxane[3], both of which inhibit cell division. This chemotherapy treatment combination is associated with significant morbidity due to medication side effects, and has a complete remission rate of only around 50%3,4. Diffusion weighted imaging (DWI) has previously been shown to identify early treatment response in HGSOC by reporting on the cytotoxic effect of platinum-based chemotherapy[8]. Conventional clinical DWI assumes that the diffusion of water follows a Gaussian distribution This approach over simplifies the movement of water in tissue, as the heterogenous spatial distribution of microstructures that obstruct diffusion (such as the membranes of cells and organelles) imparts a positive peak to the Gaussian model, termed kurtosis. Kurtosis is more apparent at higher diffusion weightings and DKI modelling is relatively easy to translate into clinical practice through the use of appropriate b-values[9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
