High-intensity focused ultrasound: past, present, and future in neurosurgery

Abstract

Since Lynn and colleagues first described the use of focused ultrasound (FUS) waves for intracranial ablation in 1942, many strides have been made toward the treatment of several brain pathologies using this novel technology. In the modern era of minimal invasiveness, high-intensity focused ultrasound (HIFU) promises therapeutic utility for multiple neurosurgical applications, including treatment of tumors, stroke, epilepsy, and functional disorders. Although the use of HIFU as a potential therapeutic modality in the brain has been under study for several decades, relatively few neuroscientists, neurologists, or even neurosurgeons are familiar with it. In this extensive review, the authors intend to shed light on the current use of HIFU in different neurosurgical avenues and its mechanism of action, as well as provide an update on the outcome of various trials and advances expected from various preclinical studies in the near future. Although the initial technical challenges have been overcome and the technology has been improved, only very few clinical trials have thus far been carried out. The number of clinical trials related to neurological disorders is expected to increase in the coming years, as this novel therapeutic device appears to have a substantial expansive potential. There is great opportunity to expand the use of HIFU across various medical and surgical disciplines for the treatment of different pathologies. As this technology gains recognition, it will open the door for further research opportunities and innovation.

Keywords: AD = Alzheimer’s disease; BBB = blood-brain barrier; ET = essential tremor; FUS = focused ultrasound; GBM = glioblastoma multiforme; GSR = global symptom relief; HIFU = high-intensity focused ultrasound; MRgFUS; MRgFUS = magnetic resonance–guided FUS; MRgHIFU; MRgHIFU = magnetic resonance–guided HIFU; OCD = obsessive-compulsive disorder; PD = Parkinson’s disease; PRPA = peak rarefaction pressure amplitude; UPDRS = Unified Parkinson’s Disease Rating Scale; VIM = ventral intermediate nucleus; high-intensity focused ultrasound; tPA = tissue plasminogen activator; tcMRgFUS = transcranial MRgFUS; tcMRgHIFU = transcranial MRgHIFU; thermal ablation.