When would you recommend delaying PMRT until after breast reconstruction is completed?

"The main thing is to keep the main thing the main thing" -Stephen Covey. We're now, as a multidisciplinary specialty, about a decade into the wide adoption of "elective mastectomy and immediate implant-based reconstruction". During this period of time, we've ironically seen an increased utilization of PMRT (more patients treated for T1-2,N1 disease). As the coordination of reconstruction and XRT has become more a routine part of our clinical practice (and challenges in treatment planning), I've tended to see a movement from mastectomy/TE placement -> adjuvant chemotherapy/TE inflation -> swap TE for implant -> PMRT....to a flow of treating with the TE in place and delaying the swap for a few months after PMRT. This is especially the case f...