Shear elasticity quantification of cancerous tumors in mice, pre and post chemotherapy treatment

Abstract

International audienceIt is believed that tumour development and its response to chemotherapy are highly correlated to variations in the tissue viscoelasticity. The monitoring through ultrasound-elastography imaging of the tumour early response to neo-adjuvant chemotherapy would be fundamental to avoid unwanted effects caused by ineffective treatments. The aim of this work is to perform a quantitative analysis using the Supersonic Shear Imaging technique of the behaviour of a human model of breast cancer implanted in mice, pre and post chemotherapy. A xenograft of a characteristic human breast cancer model is implanted on 20 Swiss-nude mice. Elasticity measurements are performed longitudinally for each mouse every 7 days from the day the tumors become measurable and correlated with histopathological results. Chemotherapy begins when tumours reach a minimum diameter of 10 mm. Ultrasound images and their corresponding elasticity maps are obtained for each mouse with a good reproducibility and accuracy. The tumours mean elasticity value and the heterogeneity increased proportionally with the diameter before chemotherapy begins. Once the treatment starts, the tumours mean elasticity value and the diameter decrease progressively. Shear elasticity quantification seems to be a useful parameter to monitor the development of breast cancer tumour and its response to chemotherapy