Doctors inject radioactive seeds to prevent women's breast cancer recurring
September 08, 2004 PM ET

TORONTO (CP) - Canadian doctors have devised a way to give some women with breast cancer a kind of "take-out" radiation that takes only a few hours to prepare and appears to have none of the nasty side-effects of traditional radiation therapy.

The treatment involves injecting radioactive seeds into a woman's breast at the site where a tumour was surgically removed, say researchers at the Sunnybrook Regional Cancer Centre in Toronto, who have so far used the experimental procedure on six women with early-stage breast cancer.

"A breast cancer diagnosis may no longer mean that women have to put their life on hold," Dr. Jean-Philippe Pignol told a news conference Wednesday.

"Treatment schedules can be difficult for women," said Pignol, a radiation oncologist at Sunnybrook. "This treatment, if proven equivalent to current standard therapy, may allow women to remain active, care for their children, go to work, remain in their community and continue their normal day-to-day activities while receiving radiation treatment."

With standard therapy, women must travel to a hospital or clinic for daily bouts of radiation for a period of about three to seven weeks in a bid to stop their tumour recurring. Many patients suffer painful burns on their breast, swelling and fatigue.

"There's a price to pay for this treatment," said Pignol.

But with the new technique, the one-time procedure takes only 30 minutes to an hour, he said. Using only local anesthetic, the doctor injects from 60 to 90 radioactive seeds into the woman's breast with a long ultrasound-guided needle. After a CT scan to ensure the seeds are located where they should be, the patient goes home.

As she goes about her daily life, the seeds slowly release radiation intended to kill off any residual cancer cells not caught by surgery. The seeds remain in place permanently, but stop emitting radiation after about two months.

So far, none of the six women - believed to be the first in the world to receive the innovative treatment - have reported any side-effects, said Pignol, adding that the treatment would likely help about 20 per cent of women with breast cancer, in particular those with small tumours that have not spread to nearby lymph nodes.

More than 21,000 Canadian women will be diagnosed with breast cancer this year, and about 5,200 will die.

The idea of using radioactive seeds, or beads, is not new. For several years, doctors have been injecting similar tiny packages of radioactive material into men's prostates to treat malignancies in the walnut-sized gland.

But until now, doctors had not figured out how to apply the same technique to breast tissue, which is more malleable, making it difficult to implant the seeds exactly in the targeted area.

To get around the problem, the Sunnybrook team designed a plastic device that allows them to deliver the seeds to their precise destination, ensuring they release radiation near the scars of the surgical site, where the cancer is most like to reoccur.

Newer radioactive materials also helped, Pignol said, explaining that these beads contain palladium, a substance that releases low doses of radiation and stays active for a relatively short duration.

Karen Todkill, one of the six patients, said the treatment was far less stressful and debilitating than the traditional radiation she's seen other women go through.

"I was back to work the next day and I'm back to resuming everything normal in my life," said the 51-year-old community relations manager from Toronto. "And I've had not one side-effect - not one."

"I think without a doubt it was much easier on me," said Todkill, who will also take the estrogen-blocking drug tamoxifen for the next five years to help prevent a relapse.

The next step for the Sunnybrook researchers is to expand the number of patients getting the treatment to determine its effectiveness over time, said Pignol, whose ultimate goal is to have cancer centres across Canada studying the procedure in thousands of patients.

"We have to be very prudent . . . We don't want to rush and open a big dam of patients."