A daily quality assurance routine for ultrasounds in vitro experiments

In few decades, the technical steps forward accomplished into the acoustic signal transduction and control fields, have brought to the safe release of a large amount of acoustic energy in the body. Today, the High Intensity Focused Ultrasound (HIFU) machines are able to induce tissue’s necrotic thermocoagulation in the region of interest (ROI) without the need of any invasive procedure, simply setting the physical parameters modulating the acoustic beam, like the phase of the elements of the transduction array. This technology found its natural employment into the treatment of solid tumors, where thermal therapies were already well established, but is now emerging for his non-thermal effects. These are the mechanical ones, first of all cavitation, for years held up as a side effect to be avoided and now seen as a possible way to enhance drug delivery or realize malignant tissues disruption through histotripsy. While thermal effects are clearly known, high repeatable and daily employed into the clinical field; mechanical effects of ultrasounds (US) are still under investigation and the way to the oncological treatment seems to be long. For these reason, but not only, HIFU in vitro experimentations are still an open field in which a nonaccurate control, could lead to inconclusive or discordant results. We approached the question suggested by the clinical practice, where a daily quality assurance (DQA) is required in order to execute a treatment. In the following paper we report the practice we established to declare our system efficiency before in vitro experiments starting.