Meattini I, Marrazzo L, Saieva C, et al. - Researchers describe the long-term outcomes of external-beam accelerated partial-breast irradiation (APBI) intensity-modulated radiation therapy (IMRT) Florence phase III trial comparing whole-breast irradiation (WBI) vs APBI in the treatment of early-stage breast cancer. Two treatment arms were: APBI arm (30 Gy in 5 once-daily fractions) and WBI arm (50 Gy in 25 fractions with a tumor bed boost). Experts assessed a 5-year difference in ipsilateral breast tumor recurrence (IBTR) between APBI arm and WBI arm following breast-conserving surgery. Findings revealed that after treatment of early breast cancer with external APBI using IMRT technique in 5 once-daily fractions, the estimated 10-year cumulative IBTR incidence was low and was not different from that post-WBI. APBI was significantly favored by the observed acute and late treatment-related toxicity and cosmesis outcomes.