Is it appropriate to consider ultra-hypofractionation for phyllodes tumors of the breast when adjuvant radiotherapy is indicated?  

There is no evidence supporting even moderate hypofractionation for these patients. That is not to say that it would not be effective, but these patients have never been studied. This is one of the only groups of breast patients I still treat with 2.0 Gy/Fx in 2025. It's a different histology, sor...