Regulation of the brain tumor microenvironment by focused ultrasound

Glioblastoma and other high-grade primary malignant brain tumors are a serious threat to the life and health of patients; consequently, their accurate diagnosis and treatment are crucial. Brain tumors are usually treated by surgical resection, radiotherapy and drug chemotherapy; however, such treatments have side effects such as trauma, infection, and radiation exposure. Furthermore, owing to limitations in conditions such as the skull and blood-brain barrier, noninvasive treatment and diagnosis of brain tumors have been challenging. In recent years, focused ultrasound (FUS) technology has shown great advantages and application potential because of its noninvasive and energy-focusing characteristics in brain tumors. From the perspective of the brain tumor microenvironment, FUS can produce mechanical and thermal effects by delivering sound waves to brain tissue; these sound waves can induce blood-brain barrier opening, radiation sensitization, targeted substance delivery, immune enhancement, angiogenesis and destruction, oxidative stress, interstitial hydraulic regulation, and brain tumor marker sonobiopsy. The feasibility and safety data from both animal models and clinical trials support FUS as having great potential for use in the diagnosis and treatment of brain tumors.