P1B-13 Simulation and Evaluation of the Sound Field of an Image-Guided Sonoporation Applicator

The success of the transportation of genes or drugs into cells via sonoporation strongly depends on the applied acoustic pressure. But especially in in vivo applications, locally deposited acoustic energy is unknown since anatomical structures like bones and the lung attenuate and reflect sound waves strongly. Therefore, the local acoustic pressure may not lie within the optimal range for sonoporation. To overcome these drawbacks, we developed an image-guided sonoporation applicator and analysed its sound field distribution in a small animal. Water tank measurements show a peak negative pressure of -1.8 MPa in water. The measured data are used as input signals for simulations of the sound field in a mouse model. Targeting the therapy device at superficial tissue, the interference of reflected and transmitted waves rises the maximal peak negative pressure by 5 dB compared to the simulation without mouse model. When targeting at subcostal organs, shadowing effects by ribs and sternum cause a variation of the peak negative pressure between 3 dB and -5 dB in the target position. The inflation of the lung can cause a deterioration of the focus. In most cases of this study focus size and position are altered as well. Thus, for safe, successful and reproducible sonoporation therapy, detailed planning or direct feedback based on 3D imaging of the small animal and a breath trigger are necessary.