Surgical scene of MagSeed®-guided lumpectomy
A surgeon conducting a MagSeed®-guided lumpectomy uses a probe to detect the magnetic field around a stainless steel seed placed in a lump in the patient’s breast, allowing for more precision in the procedure. (Photo: Courtesy Endomag)

A multi-disciplinary team at Princess Margaret Cancer Centre (PM) is the first in Canada to use magnetized seeds instead of wires in a common procedure to remove small breast lumps, reducing discomfort and improving cosmetic outcome for patients while streamlining medical care.

The procedure, known as a Magseed®-guided lumpectomy, was done for the first time earlier this year but has now been performed at the Princess Margaret on a dozen women with breast lumps that could not be felt but were detected through a mammogram or ultrasound.

"It's a very simple concept," says Dr. Michael Reedijk, a Surgeon-Scientist at the University Health Network and the surgeon who led the first procedure, which is now drawing a lot of interest from across Canada, including provincial health authorities, teaching hospitals and small rural hospitals. "It reduces the angst and the pain for patients and offers them better cosmetic outcomes while increasing the team's efficiency."

The procedure involves a radiologist placing a seed the size of a grain of rice into the breast lump to guide the surgeon in its removal. It's the culmination of more than a year of planning by a team at the Princess Margaret, which includes surgeons, radiologists, technicians, oncologists, pathologists, nurses and administrators.

"This has truly been a collective effort in the Breast Site Group," says Dr. Anne Koch, Leader of the Breast Cancer Program at PM. "It's a great example of a variety of health professionals coming together for the betterment of patient care and to move treatment practices forward."

More precision means less tissue taken

Breast cancer is the most common cancer diagnosed in Canadian women. So, a new procedure that improves the patient experience and increases the efficiency of the teams involved has the potential to have a large and positive impact on care at PM.

"It's multi-disciplinary and it's patient-centered," says Dr. David McCready, Medical Lead of the Gattuso Rapid Diagnostic Centre. "It helps all disciplines involved with breast cancer diagnosis and surgical treatment, including the patient, so it's a good news story."

In a traditional imaging-guided lumpectomy, a radiologist inserts the hook wire into the breast lump as a guide for the surgeon. Since the surgeon cannot see the tip of the wire, a mammogram is used to approximate its location.

With the Magseed®-guided procedure, a dedicated probe makes a high-pitched sound when it passes over the lump containing the seed, allowing the surgeon to cut more precisely. More precision means taking less tissue, which can lead to a better cosmetic outcome and shorter surgeries for patients.

Replacing the wire, which typically sticks out several centimetres from the breast and is coiled and taped under the woman's arm for several hours between insertion and surgery, is also more comfortable.

wire and Magseed  lumpectomy
Traditionally, a hook wire has been placed into the breast (L) to guide the surgeon in a lumpectomy. In the Magseed® procedure, stainless steel seeds are placed into the lump (R) creating a magnetic field when they come in contact with a probe placed atop the breast, more precisely guiding the surgeon. (Photos: iStock/Courtesy Endomag)

Patient Marilyn Lightstone met with Dr. Reedijk for the first time last spring, a day after he led that initial Magseed® procedure at PM. They discussed the technology and he showed a video by Endomag, the England-based company that created it. He asked if she was willing to try it. She said yes.

"It just seemed to make sense to me," says Marilyn, who was diagnosed with Stage 1 breast cancer and had a lumpectomy prior to radiation treatment, which is now complete. "It would mean less tissue was taken and I didn't have to spend the morning with a wire hanging out of me."

Since her procedure using the magnetized seed, she has spoken to a woman who had a traditional wire-guided lumpectomy and learned about the discomfort associated with it.

An alternative to wire in lumpectomies is not new. Dr. Reedijk was part of a multicentre, randomized clinical study led by Dr. Peter Lovrics of St. Joseph's Healthcare Hamilton comparing wires to radioactive seeds in the procedure. Their 2011 paper found with seeds patients had less pain, operation times were shorter, surgeons preferred the technique and there was no negative impact on breast cancer recurrence.

Since this study was published, radioactive seeds have been used instead of wires in lumpectomies at some Canadian hospitals in recent years. Work was well underway to begin using them routinely at the Princess Margaret – including the procedures to monitor and document the movement of nuclear material at each step – when members of the Breast Site Group learned of the magnetized seed technology and began researching it.

'It's so much easier with the seed'

Dr. Supriya Kulkarni, a radiologist and member of that team, last year invited a former PM resident now working at Stanford University Medical Center to come to UHN to present her work and the benefits of switching from use of wires to the new technology – magnetized seeds – in lumpectomies. Soon after, staff from the Canadian distributor for MagSeed® made presentations at PM and it was seen as a great alternative.

"It's so much easier with the seed," Dr. Kulkarni says. "You just clean the skin and drop the seed in under imaging guidance, with no wires or bandages, which is so much more comfortable and easy for the patient."

Dr. Kulkarni adds that because the magnetized seed can be put into the patient up to 30 days prior to the lumpectomy, radiologists can group all the localizing procedures, for example, doing them all on one afternoon for surgeries to be performed the next week. Freeing up radiologists – and clinic space – from inserting wires each morning, allows them to do more heavily-waitlisted procedures such as ultrasounds and biopsies, she says.

"It's so much about workflow and efficiency," she says. "This means seeing more patients in a timely manner and more organized patient care."

Magseed Team
Team members following the first Magseed®-guided lumpectomy performed in Canada earlier this year. (L to R) Dr. Karen Jang, General Practitioner Oncologist, Princess Margaret Cancer Centre and Women’s College Hospital, Dr. Michael Reedijk, Surgeon-Scientist at UHN, Jeremy Doke, Country Manager for the distributor of Endomag in Canada, Dan Sturt, Global Product Specialist, Endomag, Dr. Fernando Angarita, General Surgery Resident, University of Toronto, Ilyn Clarke, Registered Nurse. (Photo: UHN)

For pathologists, who examine the lump removed from the breast, "this makes sense in moving the field forward for the patients and the clinicians," says Dr. Susan Done, a breast pathologist and researcher.

"To have a seed within the breast that you don't even notice versus having a wire which is uncomfortable and you worry about catching on things, is a big improvement in the patient experience," Dr. Done says. "So, we were keen to participate to support our colleagues and our patients."

That drive to improve the patient experience and clinical efficiency at the Princess Margaret was a key motivator for a working group led by Terri Stuart-McEwan to implement an alternative to wires. After nearly 18 months discussing radioactive seeds and examining the safety and regulation around the handling of nuclear material, it was nearing rollout when word came of the magnetized seed option.

"All of a sudden, the whole piece of the puzzle that had been most problematic was eliminated," says Terri, who is Executive Director of Solid Tumour Oncology and the Gattuso Rapid Diagnostic Centre.

New ​technology meant new challenges including getting Health Canada approval and talking with surgeons in England who were already using the magnetized seeds. With generous support from the Gattuso Rapid Diagnostic Centre to fund the cost of 100 seeds, Terri worked with the surgical group from Britain to help make a business case, reasoning the publicly-funded National Health Service was a better comparison to Canada than the private system in the United States where the MagSeed® was also in use.

"Serendipity was at play," Terri says. "We had done a lot of work on the radioactive seeds, which meant we had learned a lot and were able to leap frog ahead when this new technology came along."

Milestone by Breast Site Group

What: First use in Canada of magnetized seeds to guide removal of a breast lump that cannot be felt

Why it matters: Less discomfort and a better cosmetic outcome for the patient compared to traditional wire-guided procedure; increased clinical efficiency for multi-disciplinary care team

How many: Since initial procedure last spring, it has been performed on a dozen women

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