PHRT

Optoacoustic-guided Focused Ultrasound (OAg-FUS) for Neurosurgery – PHRT

Project

Optoacoustic-guided Focused Ultrasound (OAg-FUS) for Neurosurgery

Short Summary

Despite recent advances in oncology, brain tumors are still considered devastating at the personal level and impose a major burden on healthcare systems worldwide. Standard treatments are limited whilst neurosurgeons are struggling to find a delicate balance between achieving efficient brain tumor extraction while causing minimal collateral damage to healthy brain tissue, which may cause irreversible cognitive or motor impairments. Indeed, discerning healthy from malignant brain tissue is a nontrivial task with the existing imaging tools incapable of providing accurate real-time feedback on therapeutic interventions. Our aim is to combine the therapeutic potential of focused ultrasound (FUS) with the imaging capabilities of optoacoustic tomography to assist neurosurgeons in their decision making and refining the therapeutic precision.

Goals

Our project aims to develop a Swiss army knife tool for image-guided neurosurgeries. Optoacoustic imaging can provide real-time deep tissue navigation with superb vascular and functional contrast and high spatial resolution. Its synergistic combination with FUS will result in a versatile OAg-FUS approach to support neurosurgeons in their difficult task of brain tumor resection.

Significance

The new theranostic approach could facilitate personalized neuro-oncological interventions, allow for multimodal tumor diagnosis and treatments within the surgical procedure further reducing time needed for the interventions.

Background

Brain tumors represent one of the most devastating and difficult-to-treat malignancies, which are responsible for substantial mortality. Treatment of patients with brain tumors imposes a major burden on the healthcare and social systems worldwide due to a global increase in incidence of intracranial cancers originated inside or outside the brain, amounting to 60 cases for every 100,000 of population. Medical technology innovations are necessary in order to extend patients’ lifespan after diagnosis and improve their quality of life. Current standard treatment consists of maximal surgical removal of the tumor, followed by associated radiotherapy and chemotherapy. Tragically, the imperative to respect healthy regions of the patients’ brain limits the therapeutic success of surgery. The whole tumor could be removed but at the cost of impaired cognitive or motor functions. Moreover, drugs are less effective in the brain due to the existence of the blood-brain-barrier (BBB) – a biochemical shield necessary for brain protection and ensuring its normal function, which however prevents the delivery of large therapeutic molecules into the brain tissue. To reduce surgically induced adverse effects, neurosurgeons need specialized tools to visualize and remove the tumor while minimizing negative impacts of the surgery. Preoperative MRI fused into real-time microscopy of the operation field has become standard in today’s operation theaters. However, once the skull is open, the intracranial pressure is released and brain tissue converts from a well-supported, geometrically stable organ into a compliant structure compressed by its own weight thus creating significant mismatches with preoperative MRI. Fluorescence imaging used to intraoperatively identify the tumor volume suffers from strong light scattering and provides no adequate resolution and penetration. On the other hand, ultrasound imaging can delineate brain tumors, but standard diagnostic devices are not appropriate for guiding simultaneous surgical tumor removal. Focused ultrasound (FUS) therapy facilitates minimally-invasive tumor removal by thermal coagulation (cooking the tissue), thereby minimizing undesirable injury to surrounding tissue. FUS is also known to enhance drug delivery through the BBB into the brain. However, strong attenuation and heating of the skull during today’s transcranial FUS interventions and the need for MRI-guidance makes the technique inconvenient and hardly applicable in a delicate neuro-oncological setting.

Technology Translation

Prof. Dr. Daniel Razansky

ETH Zurich

Co-Investigators

  • Dr. med Daniel Coluccia
  • Dr. med. Edin Nevzati
  • Beat Werner

Consortium

  • Cantonal Hospital of Lucerne
Status
In Progress

Funded by