In a randomized trial performed at 28 treatment centers in nine countries, women with breast cancer who received a single dose of radiation during breast-conserving surgery had the same likelihood of local disease recurrence as women who received a standard, weeks-long course of whole-breast external-beam radiation therapy (EBRT) after surgery. Results from the trial, dubbed TARGIT-A , were published online June 5 in The Lancet.
The researchers, led by Jayant Vaidya, Ph.D., of University College of London, randomly assigned 1,113 women to receive a single dose of approximately 20 Gy of intraoperative partial breast irradiation using a device called the Intrabeam and 1,119 women to receive EBRT at a dose of 40 Gy to 56 Gy given in 15 to 25 fractions (with an optional booster dose at the end of treatment). All of the women were 45 years of age or older and eligible for breast-conserving surgery for a single invasive tumor. Patients with known lobular carcinoma were excluded from enrollment, but patients in the intraoperative treatment group who were found to have lobular carcinoma or other high-risk disease during surgery (about 15 percent of the intraoperative group) later received additional EBRT. Hormone therapy and chemotherapy were given to women in both groups as needed.
At 4 years after treatment, six women in the intraoperative radiotherapy group and five women in the EBRT group had experienced a recurrence of their cancer in the treated breast. The researchers will continue to follow both groups of patients to monitor for local recurrences and new primary tumors outside the area treated.
Tumor recurrence, the need for radiation therapy, and speed of recovery are all factors that patients take into account when choosing treatment, explained the authors. “Because the definitive treatment with radiation can be completed at the time of the surgery or shortly afterwards in a single session with targeted intraoperative radiotherapy,” they wrote, “two of the patients’ major concerns are immediately addressed, and perhaps fewer patients should feel obliged to choose mastectomy over breast-conserving surgery either because they live far away from a radiotherapy facility or to avoid prolonging their treatment.”