Deep brain ultrasound therapy

Deep brain ultrasound (DBUS) therapy is a form of precision medicine using a technique based on the principle of high-intensity focused ultrasound (HIFU), also referred to as focused ultrasound surgery (FUS).

Technique

The method combines two main components 1:

  • guidance component
    • MRI of the the head fixed into a stereotactic frame
    • use of a coordinates system to plan the ultrasound sonications by controlling the location and extent of thermal tissue destruction
    • MRI provides a unique ability to non-invasively map temperature
  • therapeutic component
    • high power US is focused to a very small point creating particle vibrations which generate heat and subsequent cell death
    • temperatures above 56°C for 1 second result in irreversible cell death
    • for US ablation applications, the temperature ranges from 65°C to 100°C with minimal heating of adjacent tissues 2

The patient awake throughout the procedure. A stereotactic frame (similar to that used in deep brain stimulation [DBS]) is fixed onto the head. With the patient lying supine, the frame then fits into a transducer which serves for transcranial focus of US waves. The transducer contains more than a thousand individually electronically controlled US elements. Between the scalp and the hemispheric transducer helmet lies a membrane of cooling water to dissipate heat and minimise the risk of burns.

The term ‘transcranial MR guided focused US' (MRgFUS) has been used to refer to the system with all elements combined.

DBUS has current and future potential for clinical applications:

  • essential tremor 3,4 (approved by Food and Drug Administration [FDA] in July 2016)
  • Parkinson’s disease and dyskinesia 5 (ongoing clinical trials)
  • depression 6 (ongoing clinical trials)
  • obsessive compulsive disorder (OCD) 7 (ongoing clinical trials)
  • chronic neuropathic pain 8 (ongoing clinical trials)
  • brain tumours 9,10 (ongoing clinical trials)
  • reversible opening of the blood-brain-barrier to improve delivery of drugs, gene therapy and even stem cells into target areas within the brain 11-14 (pre-clinical research)

The technique contrasts to surgical DBS which is an invasive procedure requiring incisions in the scalp, burr holes and insertion of electrodes into the brain. DBS is currently still undergoing a lot of research and trials to identify new brain targets for different pathologies. Past and current research in DBS will surely lend help to the application of DBUS, with the latter potentially gaining more prominence due to its non-invasive and lower risk profile 2.

HIFU is also being used and trialled for treatment of extracranial pathology such as uterine fibroids (approved by FDA), breast cancer (cleared for use in multiple countries but not yet approved in the US), and prostate cancer (cleared for use in multiple countries including US).15-21 The Focused Ultrasound Foundation (FUSF) serves to accelerate the development and adoption of focused ultrasound - http://www.fusfoundation.org/ 22.

Share article

Article information

rID: 50372
System: Head & Neck
Section: Approach
Synonyms or Alternate Spellings:
  • focused ultrasound surgery (FUS)
  • transcranial MR guided focused US (MRgFUS)

Support Radiopaedia and see fewer ads

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.