(HealthDay News) – For women with breast cancer, intraoperative radiotherapy is a promising alternative to external beam radiotherapy (EBRT), according to two studies published online Nov. 11 in The Lancet and The Lancet Oncology.
Jayant S. Vaidya, PhD, from University College London, and colleagues conducted a non-inferiority trial involving women aged ≥45 years with invasive ductal carcinoma who were randomized to receive single-dose targeted intraoperative radiotherapy (TARGIT; 1,721 patients) or whole-breast fractionated EBRT (1,730 patients). The researchers found that, in the conserved breast, the five-year risk for local recurrence was 3.3% for TARGIT and 1.3% for EBRT (P=0.042). There was no significant difference in results for TARGIT concurrently with lumpectomy (2.1%) compared with EBRT (1.1%; P=0.31). Breast cancer mortality was similar between the groups (P=0.56).
Umberto Veronesi, MD, from the European Institute of Oncology in Milan, and colleagues randomized women aged 48–75 years with early breast cancer to receive whole-breast external radiotherapy (654 women) or intraoperative radiotherapy with electrons (651 women). The researchers found that after a median follow-up of 5.8 years, significantly more patients in the intraoperative radiotherapy vs. the external radiotherapy group had an ipsilateral breast tumor recurrence, with five-year event rates of 4.4% and 0.4%, respectively (hazard ratio, 9.3). The five-year overall survival was 96.8% and 96.9% in the intraoperative radiotherapy and external radiotherapy groups, respectively.
“Improved selection of patients could reduce the rate of ipsilateral breast tumor recurrence with intraoperative radiotherapy with electrons,” Veronesi and colleagues write.
Several authors from the first study disclosed financial ties to medical device companies, including Carl Zeiss, which manufactures the Intrabeam device.