Treatment of Liver Metastases With Focused Ultrasound and Microbubbles in Patients With Colorectal Cancer Receiving Chemotherapy.

Objective: Pre-clinical trials have obtained promising results that focused ultrasound (FUS) combined with microbubbles (MBs) increases tumor uptake and the therapeutic effect of drugs. The aims of the study described here were to investigate whether FUS and MBs could improve the effect of chemotherapy in patients with liver metastases from colorectal cancer and to investigate the safety and feasibility of using FUS + MBs.

Methods: We included 17 patients with liver metastases from colorectal cancer, selected two lesions in each patient's liver and randomized the lesions for, respectively, treatment with FUS + MBs or control.

Effect of Acoustic Radiation Force on the Distribution of Nanoparticles in Solid Tumors.

Acoustic radiation force (ARF) might improve the distribution of nanoparticles (NPs) in tumors. To study this, tumors growing subcutaneously in mice were exposed to focused ultrasound (FUS) either 15 min or 4 h after the injection of NPs, to investigate the effect of ARF on the transport of NPs across the vessel wall and through the extracellular matrix. Quantitative analysis of confocal microscopy images from frozen tumor sections was performed to estimate the displacement of NPs from blood vessels.

Nonlinear bulk elasticity imaging using dual frequency ultrasound.

The nonlinear acoustic bulk properties of tissue, e.g., the coefficient of nonlinearity, β, or the nonlinear bulk elasticity, β=βκ, have been shown to be promising parameters for tissue characterization due to their sensitivity to tissue structure.

Analysis of acoustic impedance matching in dual-band ultrasound transducers.

Dual-frequency band probes are needed for ultrasound (US) reverberation suppression and are useful for image-guided US therapy. A challenge is to design transducer stacks that achieve high bandwidth and efficiency at both operating frequencies when the frequencies are widely separated with a frequency ratio ∼6:1-20:1. This paper studies the loading and backing conditions of transducers in such stacks.