This analysis was performed only in the population who did not receive radiation after mastectomy, prospective study to compare those who received PMRT to those who did not is being planned. Furthermore, the study regarding hypofractionated RT after mastectomy could be considered. Some investigators have suggested that hypofractionated RT is also an alternative option for PMRT , although it has not been thoroughly studied as in post-breast conserving surgery RT [23–25].