Next-generation PDT and sonodynamic therapy 

Conventional photodynamic therapy (PDT) is an effective and licensed treatment for a number of conditions. It shouldn't be confused with unproven, unlicensed versions of PDT sold by some private clinics in the UK and overseas.

These so-called "advanced" versions of PDT, called "next-generation PDT" (NGPDT) and "sonodynamic therapy" (SDT), are not supported by scientific evidence.

Certain private clinics in the UK, Mexico and China promoting NGPDT and SDT have been criticised for falsely claiming that these therapies can treat late-stage cancers. Medical experts critical of these clinics believe the people running them are misguided or fraudulent.

If you or your child are seriously ill with cancer, it's understandable to feel desperate and want to try every available treatment that might help.

However, if you opt for NGPDT or SDT rather than trusted medical advice and treatment, you could be putting your life at risk. Your condition may deteriorate further and you may experience unknown side effects from the therapy.

NGPDT and SDT shouldn't even be used as a last resort for incurable cancer, as they may result in unnecessary pain and you may be faced with unaffordable costs, as the recent tragic story of Olivia Downie highlights (see below). The treatment typically costs in the region of £10,000.

The claims

Clinics promoting NGPDT and SDT market these therapies as "advanced forms" of PDT.

They sell NGPDT and SDT as natural, non-invasive therapies that use non-toxic light-sensitive substances such as chlorophyll.

These clinics claim the substances they use "explode" with oxygen, killing the cancer cells when they are activated not only by light, but also by ultrasound waves, which can apparently reach every part of the body.

They claim they can effectively treat deep or widespread cancers such as advanced liver cancer or neuroblastoma.

This is in contrast to conventional PDT, which can only have an effect through tissue at a depth of up to about 1cm and is only used to treat areas where a light source can easily reach.

What reputable health experts say

Most health experts believe that people running such clinics are either misguided or exploiting vulnerable members of the public for commercial gain.

None of the above claims are supported by scientific evidence, and stories such as Olivia Downie's (see below) reinforce the knowledge that these treatments can be harmful.

The use of NGPDT and SDT is not recommended by the 2010 critical appraisal of a clinical application of sonodynamic therapy (PDF, 327kb) concluded that:

"There is no convincing data that shows that ultrasound used in this way is effective in the treatment of primary tumours and multiple metastases [cancer that has spread]."

The authors of this appraisal also questioned how the superficial light source used can reach the deep-seated cancers in lung and bone tissues.

Furthermore, concerns were raised about the use of unproven interventions in terminally ill cancer patients, as without information proving that these unconventional techniques and substances are safe and effective, it's arguably unethical to offer them to patients – particularly those who are near the end of their life and very weak.

Olivia's story

In June 2012, seven-year-old Olivia Downie from Aberdeenshire travelled to a clinic in Mexico. She was seriously ill with neuroblastoma (a rare cancer of the nervous system) and the NHS could do no more for her.

Her mother says she hoped that the Mexico treatment would relieve Olivia's pain, which even morphine couldn't control, and extend her life for a few more months. It was her last hope.

But the treatment – sonodynamic therapy – did nothing to help Olivia. She got much worse and an ambulance was called. Olivia was put on a life-support machine and transferred to a private Mexican hospital.

Her parents were forced to appeal for money to fly her home in an air ambulance. Their pleas for her to be brought home to die touched many people and more than £150,000 was donated.

Olivia died within 48 hours of her return. Her mother deeply regrets making the trip.

Read more:

The Guardian, August 24 2012: "How children's cancer is making parents 'stab in the dark' for treatment"

Page last reviewed: 16/12/2014

Next review due: 16/12/2016