Is it acceptable to offer 26 Gy in 5 fractions for APBI rather than whole-breast RT?

Yes. We know 26/5 works for whole breast, either daily or weekly fractionation schedules. So, one can utilize that in patients that are APBI candidates. That being said, the toxicity data from Florence trial and my personal experience are excellent, so I do a hybrid approach. I give 26/5 to a larger...

This fractionation is being studied on the ACCEL clinical trial (link below). But it begs the question, why is this fractionation scheme currently being considered when you have multiple other high-quality PBI regimens with very low toxicity already supported by Phase III evidence?

Quirk et al., PMI...

The Florence trial publication preceded the UK Fast Forward publication by five years. Hence, the lower dose in the latter study becomes of interest when using the APBI technique from the former. This is only to be expected as we are always striving to find the least effective dose even when the hig...

I think it is reasonable and in low-risk populations, we do offer especially if dosimetric constraints are difficult with 30 in 5.