Applications of Focused Ultrasound in Cerebrovascular Diseases and Brain Tumors

Abstract

Oncology and cerebrovascular disease constitute two of the most common diseases afflicting the central nervous system. Standard of treatment of these pathologies is based on multidisciplinary approaches encompassing combination of interventional procedures such as open and endovascular surgeries, drugs (chemotherapies, anti-coagulants, anti-platelet therapies, thrombolytics), and radiation therapies. In this context, therapeutic ultrasound could represent a novel diagnostic/therapeutic in the armamentarium of the surgeon to treat these diseases. Ultrasound relies on mechanical energy to induce numerous physical and biological effects. The application of this technology in neurology has been limited due to the challenges with penetrating the skull, thus limiting a prompt translation as has been seen in treating pathologies in other organs, such as breast and abdomen. Thanks to pivotal adjuncts such as multiconvergent transducers, magnetic resonance imaging (MRI) guidance, MRI thermometry, implantable transducers, and acoustic windows, focused ultrasound (FUS) is ready for prime-time applications in oncology and cerebrovascular neurology. In this review, we analyze the evolution of FUS from the beginning in 1950s to current state-of-the-art. We provide an overall picture of actual and future applications of FUS in oncology and cerebrovascular neurology reporting for each application the principal existing evidences.

Ablative brain surgery: an overview

“…In 2006, Ram et al performed HIFU tumor ablation through a craniectomy in three high-grade gliomas. All of them had relatively long-term survival after treatment, and histological analysis confirmed the ablation, thus providing evidence of feasibility for this modality in the treatment of brain malignancies [14,157,168]. Subsequently, technical advancements, such as MR-thermometry and hemispheric phased-array transducers, allowed for the delivery of focused ultrasound beams through the intact skull.…”

“…These have included cryodestruction [155], SRS and several other techniques that increase the temperature within tumors, such as thermal ablation attained with RF current, microwaves [156], HIFU [157] and LITT [7].…”

“…These studies adopted computed tomography and ultrasound-guidance to deliver focused ultrasound beams to intracranial targets through a surgically created cranial defect. However, due to the lack of an accurate method to monitor intraoperative temperature, this technique did not have a sustained clinical use [14,157]. In 2006, Ram et al performed HIFU tumor ablation through a craniectomy in three high-grade gliomas.…”

An Assessment of the Relationship between Structural and Functional Imaging of Cerebrovascular Disease and Cognition-Related Fibers

“…e information in the hippocampus is the main pathway, and the entorhinal cortex is a temporary integration zone in the cortical liaison zone. In the course of AD, severe pathological changes block the transmission of information in different brain regions, the damage to the circuit is different in different cortex, and the two major cortical systems that play an important role in cognitive memory are particularly selective [11]. One is the fiber connection between the hippocampus and the adjacent cortical structure in the temporal lobe, which is reflected in the atrophy of the parasitic cortex and the expansion of the hook spacing representing the hippocampus formation and atrophy of the hippocampus cortex (see Figure 2(b)).…”

A New Era for Surgical Neurotherapeutics

“…Katz and Abel [11] provide an overview of the modern use of intracranial monitoring techniques for identifying epileptic foci in medically intractable epilepsy. Addressing a field about which there is currently much buzz, Prada and colleagues [12] discuss the evolution of high-intensity focused ultrasound, providing an overview of current and future ablative applications in oncology and cerebrovascular neurology. Darrow [13] then describes the potential for low-intensity focused ultrasound, which can both excite and inhibit neural activity reversibly to deliver a range of reversible neuromodulation therapies.…”