In a world first, doctors in the UK are trialling an innovative new way of delivering targeted chemotherapy to cancer tumours, which could improve treatment and lead to fewer side effects for patients.

The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research are testing acoustic cluster therapy which uses ultrasound waves and microscopic clusters to pump more chemotherapy drugs into tumours, without attacking nearby healthy cells.

Karen Childs is the first patient on the clinical trial and is receiving treatment for a tumour in her liver.

It will be some time before the success of the trial can be assessed and many more trials would be needed before it could be used more widely.

The BBC's been given exclusive access to the Royal Marsden Hospital in Sutton to see how it works.

Video Journalist: Laura Foster