Doctors in New England have discovered that patients receiving accelerated-partial breast radiation therapy using a balloon brachytherapy system after lumpectomy for breast cancer can develop seroma, the retaining of fluid, in their breast which can require aspiration or make monitoring them by physical exam more difficult. The study was published in the June 2006 issue of the International Journal of Radiation Oncology*Biology*Physics, the official journal of ASTRO, the American Society for Therapeutic Radiology and Oncology.

The researchers studied 38 patients who had a balloon brachytherapy catheter inserted during lumpectomy surgery to remove the cancerous tumor from their breast at Tufts-New England Medical Center in Boston and Rhode Island Hospital in Providence, R.I. With a balloon brachytherapy system, after removing the cancerous lump from the breast, doctors implant a small balloon into the space where the tumor was removed. Radiation oncologists then insert a radiation source inside the breast temporarily to deliver high doses of radiation to the tumor site to eliminate any cancer cells that may remain after surgery. This method of partial breast irradiation is currently being studied to see if it is as effective as external beam radiation after lumpectomy at keeping breast cancer from returning.

The women in the study were followed for an average of 17 months. Of the 38 patients, 76.3 percent of them developed seroma in their breast and 68.4 percent of the patients had it persist beyond six months. In addition, 11 percent of the patients required additional biopsy or surgery to rule out recurrence, due to suspicious asymmetries within the seroma cavity’s lining.

According to the study, seroma development was quite high in patients treated with a balloon brachytherapy system, when the device is placed at the time of lumpectomy surgery. Persistent seroma formation was linked to patients who had higher body weights, and was less likely in those that had a post - operative infection. It is uncertain if delaying catheter insertion to sometime other than the lumpectomy surgery will result in lower rates of seroma formation.

“Seroma is not infrequent after surgery, but it typically resolves itself within a few weeks. However, with these patients, the seroma didn’t resolve,” said Suzanne B. Evans, M.D., M.P.H., lead author of the study and a radiation oncology resident at Tufts-New England Medical Center. “We look forward to other studies in which the device is placed post-operatively to determine whether this lowers the rate of seroma formation.”

American Society for Therapeutic Radiology and Oncology (ASTRO)