Are there local control and/or toxicity differences between multi-catheter interstitial versus balloon catheter techniques for APBI?

There are no randomized comparisons to guide local control outcomes between the two. That being said the local control rates are comparable in series evaluating interstitial (Hungarian trial, GEC-ESTRO) and prospective balloon/applicator (MammoSite Registry). B39 allowed for both but no data has been presented comparing techniques and each represented a small portion of PBI patients (large percentage got 3D-CRT).

With respect to toxicity, interstitial has shown good toxicity outcomes based on ...