New research directions and novel applications

The last chapter of this section, and of this book, is a collection of topics sharing a common theme of interactions between ultrasound exposures and tissues (or agents to be delivered to them). The interest in these interactions are relatively new and therefore have not been extensively investigated. The first two topics relate to drug delivery, where the first describes a novel ultrasound mechanism for enhancing tissue permeability, and the second is the use of ultrasound energy, both thermal and non-thermal, for deploying drugs from specialized carriers that respond to this energy. The topic of the third section is immunotherapy, and describes the potential of therapeutic ultrasound for inducing an antitumor immune response as a result of ablating a primary tumor. The last topic is on metastasis, where some preliminary preclinical and clinical studies are discussed in regards to how therapeutic ultrasound may potentially affect metastatic burden.