Case: A 64-year-old female presented a challenging breast reconstruction case following radiorecurrent left-sided breast cancer. Her history included bilateral breast cancer treated with surgery and high-dose radiotherapy, leaving thin, fibrotic mastectomy skin flaps and high risk of complications with implant-based reconstruction. Given comorbidities and body habitus, autologous reconstruction was also unfavourable, limiting her options. Method: The patient underwent bilateral subpectoral tissue expander (TE) placement with an Acellular Dermal Matrix and gradual expansion to 550cc and 525cc on the left and right respectively. Preoperative US-guided measurements of cutaneous tissue thickness above the TE in 4 standardised areas were measured, marked, and photographed. Subsequently, she underwent three rounds of TE deflation and fat grafting. Results: The patient exhibited a remarkable clinical response, showing significant improvements in skin quality, including the resolution of peau d'orange appearance and lymphedema, softer skin texture and thicker skin-flaps, which were objectively assessed with serial US measurements. The regenerative effects of fat primed the skin for definitive implant-based reconstruction. Interestingly, the lower lateral quadrant displayed lowest receptivity to fat grafting, possibly due to its susceptibility to lymphedema, making it a less favourable grafting site. Conclusion: Fat grafting played a crucial role in facilitating successful breast reconstruction, in this case. This highlights the therapeutic potential of serial fat grafting in radiation-induced skin change. It offers an alternative technique for managing such cases, priming tissue, and reducing reconstructive complications.