Sonolucent cranioplasty: Is therapeutic FUS the next frontier?

Focused ultrasound (FUS) has emerged as a promising area of research in neuro-oncology. Preclinical and clinical investigation has demonstrated the utility of FUS in therapeutic applications including blood brain barrier disruption for therapeutic delivery, and high intensity FUS for tumor ablation. However, FUS as it exists today is relatively invasive as implantable devices are necessary to achieve adequate intracranial penetration. Sonolucent implants, composed of materials permeable to acoustic waves, have been used for cranioplasty and intracranial imaging with ultrasound. Given the overlap in ultrasound parameters with those used for intracranial imaging, and the demonstrated efficacy of sonolucent cranial implants, we believe that therapeutic FUS through sonolucent implants represents a promising avenue of future research. The potential applications of FUS and sonolucent cranial implants may confer the demonstrated therapeutic benefits of existing FUS applications, without the drawbacks and complications of invasive implantable devices. Here we briefly summarize existing evidence regarding sonolucent implants and describe applications for therapeutic FUS.