Ultrasound Guided Surgery as a Refinement Tool in Oncology Research

SIMPLE SUMMARY: This review describes the potential use of ultrasound as a refinement tool in research. After a general state-of-the-art discussion, the most frequent organs used as a host for orthotopic models in oncology research are listed, including the thyroid gland, heart, liver, spleen, kidney, pancreas, uterus, and testicles. In each organ and after a short ultrasonography description, the practical protocol for the ultrasound-guided injection is described as well as the main risk of the procedure and technical limitations. The main objective of this work is to help users with the use of ultrasound-guided injection. For this purpose, the descriptions of the protocols are mainly practical with tips which are frequent mistakes carried out during the injections. ABSTRACT: Refinement is one of the ethical pillars of the use of animals in research. Ultrasonography is currently used in human medicine as a surgical tool for guided biopsies and this idea can be applied to preclinical research thanks to the development of specific instruments. This will eliminate the necessity of a surgical opening for implanting cells in specific organs or taking samples from tissues. The approach for the injection will depend on the target but most of the case is going to be lateral, with the probe in a ventral position and the needle going into from the lateral. This is the situation for the thyroid gland, heart, liver, spleen, kidney, pancreas, uterus, and testicles. Other approaches, such as the dorsal, can be used in the spleen or kidney. The maximum injected volume will depend on the size of the structure. For biopsies, the technical protocol is similar to the injection knowing that in big organs such as the liver, spleen, or kidney we can take several samples moving slightly the needle inside the structure. In all cases, animals must be anesthetized and minimum pain management is required after the intervention.