Researchers developing photoacoustic hand-held probe for tumour detection during breast conserving surgery

Researchers at Lawson Health Research Institute (Lawson) are developing a hand-held photoacoustic imaging probe to be used during breast conserving surgery to quickly and accurately verify if all cancerous tissue has been removed.

Surgeons currently do not have real-time technology to guide tumour removal during surgery.

Using current tools, there is a 20 per cent chance that cancerous cells will be left behind, risking recurrence and repeat surgery.

Breast cancer represents 25 per cent of all new cancer diagnoses in women and 13 per cent of all cancer related deaths in women. Treatment for breast cancer often requires either complete breast removal in severe cases, or surgical removal of the cancerous tumour in combination with other therapies. Removing only the tumour is called breast conserving surgery.

Photoacoustic Screening

The new device is an extension of the photoacoustic screening (iPAS) technology developed in the laboratory of Dr. Jeffrey Carson, Principal Investigator and Lawson Scientist. The technique uses light and sound to capture 3D images of surgically removed breast tissue. Their studies show that iPAS can catch up to 75 per cent of missed tumour cells, decreasing the odds of failed surgery to five per cent.

Dr. Muriel Brackstone, Associate Scientist at Lawson, Head of the Breast Care Clinic at St. Joseph’s Hospital London, and Surgical Oncologist at London Health Sciences Centre, brings her clinical expertise to the project.

“With the first generation iPAS technology, we would remove the tumour, take it to the lab for imaging and wait to see if there was a rim of normal tissue around the removed tumour so we knew it was removed completely. The wait was anywhere from 20 minutes to an hour. During that time, the patient is under anesthesia, the surgical team is idle and precious OR time is being used,” explains Dr. Brackstone.

A hand-held tool that surgeons can use

Creation of a hand-held probe to be used in the operating room is the next step in the advancement of this new technology. Elina Rascevska, biomedical engineering student at Western University, recently joined the Lawson team to convert lab-based iPAS technology into a hand-held device.

“We have developed a prototype of the iPAS probe, and once we can verify the quality of the images it produces, we will give it to Dr. Brackstone to test in the OR,” says Rascevska.

The iPAS probe does not need a trained operator and would be used by the surgical team. Instead of imaging the removed tissue, it scans the surgical cavity in real time to give the team a faster and more accurate indication as to whether the cancerous tissue has been removed.

“If we can progress this technology to a point where physicians can use it as part of standard protocols, we will have reduced the amount of time each patient needs to spend in the OR, the amount of call-backs and repeat surgeries, and ultimately improve quality of life for patients with breast cancer,” adds Dr. Carson.

(From left): Dr. Jeffrey Carson, Elina Rascevska, Dr. Muriel Brackstone