An Oct. 19 Health article about Mammosite, a new radiation treatment for breast cancer, listed an incorrect phone number for Holy Cross Hospital, which offers the treatment. The correct number is 301-754-7922. (Published 10/21/04)

A new breast cancer therapy that dramatically reduces the length of post-lumpectomy radiation may ease the decision-making process for some older patients torn between breast-conserving surgery and mastectomy.

The treatment, known as MammoSite, relies on a surgically implanted catheter and tiny balloon-like device to deliver targeted radiation to the affected part of the breast. During twice-daily treatments given over five consecutive days, a thin wire with a radioactive "seed" is inserted through the catheter into the balloon to irradiate the tumor site and the area immediately surrounding the cavity where tumors are most likely to occur. Each daily dose takes about 10 minutes and is painless. Once the treatment is completed, the catheter and balloon are removed. The radiation system is manufactured by Proxima Therapeutics Inc. of Alpharetta, Ga.

In contrast, traditional post-lumpectomy radiation therapy requires five to seven weeks of five-times-per-week treatments -- a schedule that can be difficult for many women. "Maybe it's a two-hour drive to radiation and the woman has two children -- MammoSite offers these women another option," said Donna Appel, a nurse who oversees MammoSite treatment at Holy Cross Hospital in Silver Spring, one of two Washington-area facilities offering it.

Approved by the Food and Drug Administration (FDA) in 2002 and in Europe a year earlier for treatment of early-stage breast cancer, MammoSite has drawn the interest of physicians aware that the convenience factor sways some patient decisions on lumpectomy vs. mastectomy.

"I do have some patients who opt for mastectomy because, for whatever reason, they don't want the six or seven weeks of radiation treatment," said Shawna Willey, director of the Betty Lou Ourisman Breast Health Center at Georgetown University Hospital, which also offers MammoSite treatment. (The therapy is also available at the University of Maryland Medical Center in Baltimore.)

But while the therapy offers greater convenience, it's not yet clear how it stacks up long-term against whole-breast irradiation -- the standard treatment for women who choose lumpectomy. Whole-breast irradiation relies on an external beam of radiation applied to the entire breast where the cancer was found. The premise is that undetected cancer cells might have escaped from the original tumor to other parts of the breast and that the radiation will kill them.

According to an FDA release on MammoSite, regulators cleared the device based on clinical data from only 25 women who had the device implanted after lumpectomy. The American Society of Breast Surgeons has just begun to evaluate reports by some 1,300 breast surgeons using MammoSite over the last 18 months. The first large, randomized study comparing MammoSite to other abbreviated breast cancer therapies is now being planned by the National Cancer Institute.

MammoSite's costs are comparable to those of traditional radiation therapy, with both kinds of treatment coverable by insurance. However, physicians say some patients have been denied reimbursement for the MammoSite catheter, which can cost several hundred dollars.

For now, careful patient selection is key to ensuring the best outcome, said Sheela Modin, chief of women's brachytherapy for Maryland Regional Cancer Care, which has been offering MammoSite at Holy Cross Hospital since 2003.

The ideal patient is over 45 and has a small invasive tumor, she said. The location of the cancer is also important -- it cannot have spread to the lymph nodes and it can't be too close to the skin.

"We're being very careful about the selection criteria," Modin said, noting that only about 20 Holy Cross patients had opted for MammoSite over the last 15 months. "We've had women say, 'No, thanks. I'll just do the standard treatment.' "

But a lack of certainty about the outcome did not outweigh the convenience for Hyattsville art instructor Crisley McCarson, so far the only Georgetown patient to opt for MamoSite after meeting stringent selection criteria.

"Seven weeks of radiation five days a week was not something I was looking forward to," said McCarson, who chose Georgetown for radiation therapy specifically because of MammoSite. "This way I was done by the beginning of August. I could get on with my summer."

Resources

For more information on MammoSite, see www.proximatherapeutics.com.

For information about treatment locations:

* At Holy Cross Hospital, call Donna Appel, 301-743-7922.

* At Georgetown, call the Ourisman Breast Health Center, 202-444-3315.

* At the University of Maryland, call 410-328-2326.

-- Rita Zeidner