A single dose of targeted radiotherapy (TARGIT-IORT) during surgery is just as effective as conventional radiotherapy (EBRT) for most women with early breast cancer, a study published in The BMJ found. 

EBRT requires several trips to the hospital post-surgery and targets the entire breast. TARGIT-IORT, on the other hand, is given immediately after surgery and is restricted to the area around the tumor. 

The randomized study was composed of 2298 women aged 45 and older who were eligible for breast conservation surgery at 32 centers across 10 countries in the United Kingdom, Europe, Australia, United States, and Canada. Between March 2000 and June 2012, 1140 women were selected to receive TARGIT-IORT, whereas 1158 patients received EBRT. TARGIT-IORT was administered immediately after surgery during the procedure under the same anesthetic, while the external therapy was administered as a standard daily dose for 3-6 weeks after surgery, according to the study. 

The long-term results of TARGIT-IORT were no worse than the standard therapy, according to the study. After 5 years of follow-up, the local recurrence rate for the targeted therapy was 2.11% compared with 0.95% for EBRT. The difference is not considered to be clinically significant. Of the 1140 patients who received TARGIT-IORT, 24 saw a recurrence, which is 13 more than the external group; however, the TARGIT-IORT yielded 14 fewer deaths.  

“…risk adapted immediate single-dose TARGIT-IORT during lumpectomy is an effective alternative to EBRT, with comparable long-term efficacy for cancer control, and lower non-breast-cancer mortality," the study authors wrote.

There were several limitations to the study, such as the possible overdiagnosis of non-invasive local recurrence affecting the results and not collecting all the background risk factors for deaths from non-breast cancer causes. However, the study also had several strengths, such as a large sample size with a long duration and a high level of complete follow up. 

Reference:

Single dose radiotherapy as good as conventional therapy for most women with early breast cancer (News release) BMJ, August 19, 2020, EurekAlert! Accessed August 20, 2020