Is multifocal disease an indication for RT in an elderly patient with early stage and otherwise favorable breast cancer?  

IBTR for upfront unifocal and multifocal disease is similar and would not change recommendations for me if all other factors were favorable.

Agree with above, though I did just see a healthy woman in her early 70s with a two site lumpectomy for two favorable small tumors.  Though RT will not improve OS, I expect the cumulative risk for LR is likely higher for her (given the two sites have an independent risk for recurrence), and I l...