More than 20,000 people are diagnosed with upper abdominal cancers a year in the UK, of which more than half die. A new treatment could offer an alternative to chemotherapy and surgery, which for abdominal cancers is often either not possible or offers poor outcomes.
The intention of high intensity focused ultrasound (HIFU) surgery is to direct energy very accurately at tumours of the liver, kidney and pancreas. The danger in most ablative treatments, however, where tumour cells are destroyed by raising their temperature, is that surrounding healthy tissue can be damaged. Using HIFU, the energy can be focused into a very small and well defined volume, reducing the risk of harmful side effects.
The research team, led by Nader Saffari and Eleanor Stride from UCL Mechanical Engineering, have been working with David Hawkes and Dean Barratt from UCL Centre for Medical Image Computing, Gail ter Haar from the Institute of Cancer Research (ICR) and Constantin Coussios of the University of Oxford.
The technique works by raising the temperature of an area of cancerous tissue above 55-65 degrees Celsius for 1 second, which immediately kills the cells. However, there are several obstacles to overcome before this technique can be safely and routinely used in the clinic. For example, the treatment will need to transmit energy through the rib cage, which could increase the risk of skin burns and damage to the rib surface. Similarly, since the patient will be breathing, the effects of movement on the accuracy of the treatment need to be explored. Cavitation may occur as a result of the treatment, and these effects need to be fully considered. Finally, there is currently no effective technique for real-time image guidance and treatment monitoring, which will be required if the technique is to be applied successfully.
To tackle these issues, the different partners in the project are each bringing their own particular expertise. UCL Mechanical Engineering is developing patient-specific treatment planning software whilst analysing and correcting for organ motion is a specialisation of the UCL Centre for Medical Image Computing. The unit at the University of Oxford, will develop methods for real-time monitoring in close collaboration with the team at the Institute for Cancer Research, that have expertise in developing and testing HIFU systems and conducting clinical trials.
The overall objective of the research programme is to develop practical solutions for these issues. Dr Saffari said: ‘It is hoped that at the end of this five year project we will have a prototype system ready for clinical trials’.