A tiny radioactive device the size of a mere sesame seed is being used to help surgeons at the CHUM locate tumours in breast cancer patients during surgery.

Called a 'radioactive seed,' the wee device is cutting down on wait times, costs and stress.

Radiologists use guided mammography to insert the radioactive isotope wrapped in a titanium shell.

“We freeze the skin, put the seed in a needle and we go and put it directly into the tumour,” said CHUM radiologist Dr. Julie David.

During the operation, surgeons use a machine called a gamma probe to hear the seed's radioactivity, allowing them to precisely locate the tumour and make their incision.

“In previous generations, women would show up and have a palpable mass. So they would feel a mass, they'd see their family doctor who would say yes, it's worrisome,” said surgeon Dr. Erica Patocskai.

Today, breast cancer is often discovered while the tumour is small and can't be felt.

The new method is more efficient, explained Patocskai, allowing the hospital to perform more surgeries in a day. That cuts wait times and ultimately makes life less stressful for patients.

“If I see a patient and I can say their operation is in three weeks instead of four -- which doesn't seem like a big difference for us, but if you're at home waiting for a phone call, it is a big difference,” said Patocskai.

The seed can be inserted up to five days before surgery, unlike the older guidewire method.

“The patient has to have the guidewire put in the morning of the operation and then she can't touch her breast. So the guidewire could move,” said Patocskai.

The CHUM has been using the seed since 2013 and so far is the only hospital offering it in the province. Doctors are hopeful it will catch on.

Patient Marie-Eve Julien, who was diagnosed with stage 2 breast cancer last month, said it has given her peace of mind.

“The procedure was easy,” she said. “And not at all stressful.”