Intrabeam

By: William A. Thompson, III, MD, FACS

For Stage I and II breast cancer, lumpectomy provides equivalent survival to a mastectomy, provided adjuvant radiation is employed.  According to the American College of Surgeons, greater than 25% of patients in the United States who need radiation following a lumpectomy did not undergo radiation. In Alabama, this number is greater than 40%. Traditionally, high energy radiation is delivered externally 5 days a week for up to 7 weeks.

Within the past 10 years, it has become apparent that select patients can forgo extended whole breast radiation in favor of partial breast irradiation delivered twice a day through a percutaneous catheter that the patient would wear for about one and a half weeks to 2 weeks. The optimal patients are older than 45, have a tumor less than 3cm, have negative margins of excision, and ideally would be node negative. This is certainly more convenient than 6-7 weeks, but does add the discomfort of additional surgical procedures with catheter insertion, keeping the area dry for greater than a week, and having a medical device protruding from the breast for 1 to 2 weeks.

The most recent advance is a single dose of radiation delivered in the operating room while the patient is under anesthesia. The INTRBEAM system is a small portable electronic X-ray source that delivers radiation via a spherical applicator immediately after the lumpectomy following pathologic margin assessment. The duration of therapy depends on the volume of the applicator used, typically between 25 and 50 minutes. The lifestyle advantages are obvious. Daily radiation therapy for an employed patient is inconvenient at best, and for a more infirmed or rural patient may be completely untenable.

This exciting new therapy is supported by a  greater than 2000 patient  multicenter trial presented at the American Society of Clinical Oncology meeting in Chicago 3 years ago and published in the prestigious journal, The Lancet in July 2010. A follow up presentation at the December 2012 San Antonio Breast Conference showed no breast cancer 5 year  survival benefit to receiving 6 weeks of therapy compared to a single dose intraoperatively. In fact, there was a trend for improved overall survival in the INTRABEAM arm due to fewer non-breast cancer deaths.

Currently, Trinity Hospital is the only hospital in the state and one of about 40 facilities nationwide to use the INTRABEAM.  These hospitals include Georgetown, NYH-Cornell, Florida-Gainesville, and USC-Los Angeles. A clear impediment to wider state wide use has been reimbursement. Despite a willingness to pay thousands of dollars for catheter based therapy which has far weaker data, Blue Cross/Blue Shield of Alabama has refused to pay the several hundred dollars for the INTRABEAM. That deterrent however has not prevented Trinity surgeons and radiation therapists from delivering this treatment to Alabamians many who would not have had radiation therapy otherwise.

 

 William A. Thompson, III, MD, FACS