A new study suggests that risk-adapted immediate single dose intraoperative radiotherapy (TARGIT-IORT) after lumpectomy has similar long-term local control and survival outcomes compared with conventional radiotherapy.
The study by an international team from 32 centres in 10 countries, randomised 2298 women aged 45 years and over, with invasive ductal carcinoma on a 1:1 basis, to receive either TARGIT-IORT, which was given immediately after lumpectomy or conventional treatment, involving daily fractionated courses of external beam radiotherapy (EBRT), for 3 to 6 weeks. The main outcome of the trial was defined as non-inferiority (of the two procedures) with a margin of 2.5% for the absolute difference between the 5-year local recurrence rates and long-term survival.
At 5 years, the difference in local recurrence between both arms was 1.16% (90% CI 0.32–1.99) and there were 14 fewer deaths in the TARGIT-IORT group. After a median follow-up period of 8.6 years, there were no significant differences in local recurrence-free survival (hazard ratio, HR = 1.13, p = 0.28) between the two arms.
The authors concluded that in eligible patients, TARGIT-IORT was an effective alternative to standard therapy (EBRT) and is associated with an approximately 80% of avoiding a full course of radiotherapy.
Vaidya JS et al. Long term survival and local control outcomes from single dose targeted intraoperative radiotherapy during lumpectomy (TARGIT-IORT) for early breast cancer: TARGIT-A randomised clinical trial. BMJ 2020;370:m2836.