Medical Biophysics PhD candidate Derek Gillies is working to give surgeons a clearer view – and liver cancer patients a better outcome – thanks to a new 2D/3D imaging system.
Currently, surgeons use a 2D ultrasound to place a needle electrode through the skin into a liver tumour. High-frequency electrical currents then pass through the electrode to create heat and destroy the cancer cells. Despite the popularity of the procedure, up to 15 per cent of patients will have a recurrence of the cancer because a surgeon did not completely remove the tumour.
This type of minimally evasive procedure has its downfalls, Gillies said.
2D ultrasounds do not provide enough anatomical landmarks for surgeons to target precisely. In addition, because the liver is located above the diaphragm, any time a patient breathes during the procedure the liver can move up to 3 cm. This movement can lead to not treating the entire tumour – leaving a chance for cancer to return.
Gillies’ combination 2D/3D imaging system uses an algorithm to stabilize the image of the liver and provide real-time guidance as the surgeon removes the tumour.
“We get a lot of criticism that it’s not really a big deal. People says interventional radiologists are doing hundreds of these procedures and you trust their skill,” he said. “But if you say that in any other domain, ‘just trust the skills,’ nobody just trusts people.”
Gillies shared his work last week as part of the 5th annual London Health Research Day, which showcased more than 400 research projects from students, trainees and postdoctoral scholars at Lawson Health Research Institute and the Schulich School of Medicine & Dentistry.
Liver cancer can face a number of surgical options – from transplant to removal of a portion of the organ to interventional procedures, such as radiofrequency ablation. Those latter, minimally evasive procedures are quickly becoming commonplace by treating 70 per cent of patients who are not viable candidates for transplant or resection.
In men, liver cancer is the second leading cause of death worldwide, mostly in developing countries.
Cancer cells are not that different from soft tissue. This difficulty in distinction led Gillies to develop the 3D ultrasound system to provide more information to radiologists.
“You want to get to the centre of the tumour. But the tumour isn’t a circle; it’s a sphere. There is a lot of subjectivity and it is based on the radiologists feelings. If you had a 2D image, and you get to the centre, it doesn’t necessary mean you’re at the centre of the tumour. We want to get a third dimension so you can actually slice it,” said Gillies, adding once segmented, often times a margin of about 5 mm is added around the tumour to account for any cellular debris that is not part of the cancerous mass.
Within the next few years, the 2D/3D imaging system will be the go-to tool for interventional procedures on the liver, Gillies said, noting he’s already proved its success in dealing with prostate biopsies.
“We’re providing radiologists with a lot of extra information,” he said. “People think there is no room for improvement, but there is so much room.”
