Viral therapies that fight ovarian cancer to be trialled using PET scanning

Friday 15 September 2006

PET Positron Emission Tomography More Information ROLLOVER

The research demonstrates how PET scanning can be used to see both how the virus behaves and how the cancer responds. This means that scientists can gain an accurate picture of the effects of the drug therapies whilst they are working in the body, and refine and improve them accordingly.

Ovarian cancer causes changes that are difficult to quantify by conventional imaging due to the location, presentation and biological characteristics of the disease. PET scanning, however, is a nuclear medicine imaging technique which produces a three dimensional image of the body. It enables researchers to see early changes in the development of the disease which happen before changes in the size of the tumour.

Self-replicating viral therapies, previously mainly trialled on animal models, are versions of viruses that are tailored to replicate inside the body and to infect and kill cancer cells. They are designed to multiply and kill cancerous cells rather than healthy ones.

Trials in animal models have shown that these therapies can be effective in fighting tumours but that their effectiveness is limited to a certain time period, after which point the viruses die. The researchers hope that analysing the behaviour of the viruses using PET scanning will allow them to alter the viruses' properties to increase their effectiveness.

Professor Eric Aboagye, one of the researchers on the study from Imperial College's department of Oncology and Imaging Science and the MRC Clinical Sciences Centre, said: "Using self-replicating viruses to fight cancer is a relatively new idea and it shows a lot of promise for fighting diseases such as ovarian cancer, where sadly the prognosis for patients is quite poor.

"In order to make the best possible therapies we have to be able to see exactly how they work inside the body. This new research shows we can do this fairly quickly and easily with PET scanning and it means we can test this and newer versions of the viruses in clinical trials, taking the development of such therapies an important step forward," he added.

PET scanning works by scanning for a radioactive tracer injected into the body. Where the viral therapies kill cancerous cells, their uptake of the tracer is reduced and these changes are visible on the scanner.

Dr Iain McNeish, a researcher from Queen Mary's School of Medicine and Dentistry and a co-author on the paper added: "These results are extremely exciting. For the first time, we can image the effects that our viruses are having upon cancer cells within whole living organisms very rapidly. As a result of these results, we will be using PET scanning on patients being treated with self-replicating viruses in the clinical trials that we hope will be starting at Barts Hospital in 2007."

The research was funded by Cancer Research UK. Dr McNeish will be leading clinical trials into the new therapies in conjunction with the Cancer Research UK Drug development office.

Source / Credit: Imperial College London