Day-glo dye helps surgeons to trace trickiest tumours

A FLUORESCENT dye that makes tumours glow green is helping doctors seek and destroy hardto-reach tumours. It may spare patients the agony of limb amputations – sometimes needed to ensure no cancerous cells are left behind.

British doctors are using the substance to help identify a type of cancer called sarcomas, which affect thousands every year.

Sarcomas are cancers of the body’s connective tissue and can occur in bones, muscles or even cartilage. They often become entwined with healthy tissue, either on the outside or inside of the body.

The risk of this cancer spreading is high, so surgeons must cut away a substantial portion of healthy flesh along with the tumour – in severe cases, it may mean a limb.

But surgeons can struggle to work out what is cancerous and what is healthy, which can make operating challenging.

Relying only on scans for guidance, they could unnecessarily remove too much healthy tissue – or not take enough.

Now, using a dye which glows under a special, hand-held camera, surgeons can see where the cancerous tissue ends, making surgery for sarcomas more precise.

Kenneth Rankin, consultant orthopaedic surgeon at Newcastle Hospitals, who is pioneering the approach, says: ‘This is about preserving function for patients without compromising the outcome of their surgery.

‘It may avoid an amputation. Or it may be that we can confidently preserve an important nerve or blood vessel. For patients, that can make a big difference.’

Sarcomas are usually diagnosed when they are about the size of a large tin of baked beans. The main treatment is an operation to remove the tumour, sometimes in combination with chemotherapy and radiotherapy. Depending on which part of the body is operated on, patients may have some difficulty with movement afterwards if nerves are damaged.

The dye, known as indocyanine green, is injected into sarcoma patients ahead of surgery and appears to be absorbed quickly by tumours. As the tumour is removed, the surgeons hover a specially developed camera – which uses an infrared light – over the wound area. Mr Rankin says: ‘It’s just like holding a barcode scanner.’

The camera beams a live, moving image on to a high-resolution television in the operating theatre.

Cancerous areas that have absorbed the dye will appear green on the screen. The surgeon can use this image to decide which tissue to cut out and which to leave.

Since February, the dye has been used in 11 patients having surgery for sarcomas at Freeman Hospital in Newcastle.

Diane Rudd, 55, from Guisborough, North Yorkshire, was treated with the new technique last month. The mother-of-two first noticed a lump in her right upper arm four years ago, and a year ago it started to become painful. In August, she was diagnosed with pleomorphic rhabdomyosarcoma – a rare form of sarcoma.

Scans revealed the 7cm lump in her bicep had spread near a major artery and nerves to her fingers.

In October, surgeons operated on the tumour – with the assistance of the green dye to try to preserve as much function in her arm as possible. Her whole bicep was removed and muscle from her back was moved into her right arm.

‘I was so relieved when I woke up in recovery to find I had feeling in my arm and could still move all my fingers,’ she says.

Diane was sent home after nine days in hospital and will soon begin six weeks of radiotherapy.

The dye has also been used to help treat breast and bowel cancers.

‘We are still in the early stages of evaluating this technology,’ Mr Rankin says. ‘In the long term we hope it will allow us to safely take less healthy tissue from patients without compromising their cancer outcome.’