Avatars of patients used during surgery Melbourne surgeons are using technology that turns patients into avatars on computers so they can navigate their bodies with unprecedented precision. The life-saving technology is being used for brain and spine surgery which has been impossible in the past due to navigational issues. Professor Peter Choong, director of orthopaedic surgery at St Vincent's Hospital, said he had been using a "stealth guidance machine" to recreate patients on a computer so he could monitor movements in their body during surgery. He said the machine used information from patient's scans, such as CT, MRI and PET scans, to build a 3D model of their head or spine. This is then electronically matched to the patient's body during surgery using special infrared cameras so he can see "virtual" tissue showing the precise location of important structures like bone, nerves and blood vessels in relation to his instruments. If I move the patient around, the patient's avatar on the screen moves around and the computer says if you're at this angle and you want to change to this angle, you must make the following cut at this angle. It shows how many degrees and how many millimetres. It's very much like flying a plane," he said. It says where you are in relation to particular parts of the body. Professor Choong said the machine meant surgeons could operate on patients with previously inoperable tumours in difficult to reach places where there was a risk of cutting vital nerves and blood vessels or spreading cancerous tumour cells. It also aided brain surgery on people with Parkinson's disease and epilepsy. Previously we had to assume certain things, so it has increased the accuracy of our understanding of where important structures are ... It has also allowed us to cut less than what we used to cut out," he said. About a year ago, he used the machine to remove an eggplant sized tumour from Melbourne man Kenny Le's sacrum - the large, triangular bone at the base of the spine. The cancerous tumour was threatening Mr Le's life and could not have been removed without the machine. Over a marathon 48 hours, Professor Choong's surgical team removed Mr Le's sacrum while protecting important nerves he needed to walk, and then reconnected his spine to his pelvis. "There was absolutely no room for error," said Professor Choong. The Stealth enabled us to operate with such precision and reattach delicate parts of the spine. Mr Le, a father of two young children, said he was thrilled to be cancer free and able to walk one year on. It's amazing. I feel very lucky," he said. But Professor Choong said some patients were missing out on the use of the technology because limited funding meant St Vincent's could only afford one of the machines. He and Mr Le are now aiming to raise $444,000 to purchase a new machine at the St Vincent's Scrubs Run on March 3 so more patients can benefit. "We'd like to raise awareness of how important this technology is," Professor Choong said. It's potentially life saving.