Focused ultrasound in pediatric neuro-oncology: Current applications and future directions

Focused ultrasound (FUS) is a minimally invasive procedure with recent applications to patients with neurosurgical conditions. To date, most neuro-oncologic applications of FUS have occurred in the adult population to target high-grade gliomas and brain metastases. Its potential applications in pediatric neuro-oncology are only just starting to be realized. In children, high-intensity focused ultrasound (HIFU) has been used to treat benign intracranial lesions such as hypothalamic hamartomas and subependymal giant cell astrocytomas. Experience is now accruing with the use of low-intensity focused ultrasound (LIFU) in conjunction with systemically administered microbubbles in children to disrupt the blood-brain barrier (BBB) using magnetic resonance-guided focused ultrasound (MRgFUS). The pediatric brain tumor for which this application has been used is diffuse intrinsic pontine glioma (DIPG), a typically fatal neoplasm in children ages 5-7 years. Here, the history of FUS is reviewed, the principles of FUS therapy are delineated, and a discussion of its applications in neuro-oncology with a focus on pediatric neuro-oncology is provided. Innovations in MRgFUS are ushering a new and exciting era of minimally invasive treatments for children with brain tumors.