We know sound soothes us. But what if it could kill a tumour?

Sound has been used for centuries to soothe, treat and heal. An analgesic to some, a mood elevator to others, the use of sound to restore human health has ranged from ancient Tibetan singing bowls to bona fide “sound healers” who treat symptoms of physical and emotional conditions using sound to manipulate brain waves.

But what if sound could destroy a tumor? What if it could treat diseases as diverse as Parkinson’s and Alzheimer’s; epilepsy; depression; obsessive-compulsive disorder; arthritis; back pain; and tumors of the brain, breast, prostate, liver and pancreas?

It may sound like science fiction or Star Trek to some, but it isn’t. Named one of the 50 greatest inventions by TIME magazine, and credited with “changing medicine” by Fortune magazine, focused ultrasound is a new, highly disruptive, game-changing, non-invasive therapeutic technology that has the potential to be as revolutionary to therapy as magnetic resonance scanning (MRI) has been to diagnosis. But it's still early in its development.

The basic principle is similar to using a magnifying glass to focus beams of sunlight on a single point to burn a hole in a leaf. With focused ultrasound, multiple intersecting beams of ultrasound energy are concentrated on a target deep in the body with extreme precision and accuracy (sparing adjacent normal tissue).

Where each individual beam passes through the body there is no effect. But at the focal point where the beams converge, the focused ultrasound energy induces a variety of biologic effects including: destroying tissue, stimulating the body's immune response, and the delivery of drugs. The location of the focal point and the treatment effect is guided and controlled in real time by ultrasound or MRI.

The science supporting the benefits of focused ultrasound is robust, with hundreds of peer-reviewed journal publications per year including clinical trial data in prestigious medical journals such as the New England Journal of Medicine and The Lancet. This data has provided safety and efficacy evidence leading to 22 regulatory approvals around the world to date, including five by the US Food and Drug Administration, with more than 75 additional clinical indications in various (mostly early) stages of development.

Focused ultrasound is a powerful treatment method that provides an alternative or adjunct to surgery, radiation therapy, drug delivery and cancer immunotherapy. It is already transforming treatment, improving outcomes and decreasing the cost of care for a number of conditions.

For example, the US FDA recently approved FUS to treat essential tremor, a neurological disorder. This marked the first brain indication for the technology in the US and a welcome, non-invasive alternative to intrusive Deep Brain Stimulation – based on clinical trial data showing a nearly 50% improvement in tremor and motor function in patients three months after FUS treatment, with 40% retaining improvement after one year (patients in the control group experienced no improvement at all).

More than 150 ET patients have now been successfully treated to date, and focused ultrasound centers worldwide are reporting a backlog of several hundred patients desiring FUS.

Focused ultrasound is also an attractive treatment for women with uterine fibroids (approved for this use in the US in 2004). A nationwide study of nearly 1,000 American fibroid sufferers – published in the October 2013 issues of both the American Journal of Obstetrics and Gynecology and the Journal of Women's Health – found that when presented with fibroid treatment descriptions, the majority surveyed (60%) rated focused ultrasound as their top treatment choice. Women often cite the rapid return to normal activity, no incision or hospital stay, and minimal complications as benefits of the treatment. To date, FUS has been performed on more than 72,000 women with fibroids worldwide.

While the pace of research is rapidly accelerating, and momentum for the entire field is growing, there is an enormous amount of work to be done, and many barriers to overcome, before focused ultrasound becomes a standard of care where it can help millions of patients.

Still years from now, when the potential of focused ultrasound is realized and it becomes a mainstream therapy, it will result in a change in treatment paradigms and health policy that will affect countless patients around the globe.

Find out more at www.fusfoundation.org. Dr Kassell is a member of the World Economic Forum's Global Future Council on Neurotechnology and Brain Science.