A retrospective analysis indicates that low-energy radiotherapy during excision of recurrent breast cancer can provide an alternative to mastectomy for patients who have undergone breast-conserving surgery with external-beam radiotherapy.
Intraoperative radiotherapy delivers high doses to a restricted area at risk, that is, to the tissue adjacent to the tumor cavity after tumor resection, principal investigator Dr. Frederick Wenz and associates explain in the September 14th online issue of BioMed Central Cancer.

"Normal tissue tolerance does not permit a second full-dose course of radiotherapy to the entire breast after a second breast-conserving surgery," they note, so low-energy X-rays, which are characterized by a sharp dose fall-off with distance, are advantageous for intraoperative radiotherapy.

Between April 2002 and November 2006, 17 patients were treated with intraoperative radiotherapy at the Mannheim Medical Center, University of Heidelberg. Fifteen of the surgeries using intraoperative radiotherapy were for in-breast tumor recurrences and two were for new primary breast cancer after previous partial breast external-beam radiotherapy for Hodgkin's disease. Median age of the patients was 65.8 years (range: 48.3-86.9).

After a median follow-up of 26 months after breast-conserving surgery with intraoperative radiotherapy, there were no local recurrences. Fourteen of the 17 patients were alive and free of disease progression, two were alive with distant metastases, and one died from pulmonary metastases diagnosed after breast-conserving surgery with intraoperative radiotherapy.

The cosmetic outcome was judged to be excellent in seven cases, good in seven and fair in three.

"Intraoperative radiotherapy for recurrent breast cancer using low-energy X-rays is a valuable option for patients with recurrent breast cancer after previous radiotherapy," the researchers conclude.

Though mastectomy continues to be the standard of care for in-breast tumor recurrence, the researchers note, "there are some reasonable arguments for a second breast-conserving approach."

For example, they point out that mastectomy does not eliminate the risk of local recurrence, since approximately two to 32 per cent of mastectomy patients develop a chest wall recurrence.

And based on other studies, the researchers point out that the survival-limiting factor for patients with in-breast tumor recurrence is not the risk of recurrences within the breast, but rather distant metastases.

"This is the first report on using breast Intraoperative radiotherapy for in-breast recurrences," Dr. Wenz told Reuters Health. "Intraoperative radiotherapy for breast cancer during breast-conserving surgery was introduced about five to seven years ago, but is still under study. Worldwide, fewer than 3000 patients have been treated with this approach.

---