ABSTRACT
Focused ultrasound (FUS) is an emerging approach for transcranial image-guided surgery, allowing the deposition of ultrasound energy onto discrete targets in the brain. Many of the putative mechanisms of FUS are likely to co-occur and may eventually be amenable to rational combined approaches targeting multiple aspects of cancer pathobiology. High-intensity FUS is also being investigated for hyperthermia therapy involving prolonged sublesional temperatures for radiosensitization and histotripsy for tissue ablation by mechanical forces. Low-intensity FUS is being investigated for blood–brain barrier (BBB) opening, ultrasonic uncaging of therapeutics, neuromodulation, and liquid biopsy. Radiation can contribute to tumoral immunosuppression, where FUS thermoablation may enhance tumor immunogenicity and induce an immune response. The brain is served by a dense network of capillaries, with the brain parenchyma formed by a network of densely packed cells and extracellular matrix that can impede drug mobility even after passage across the BBB.
