High-Resolution Ultrasound Evaluation of Structural Remodeling After Fat Grafting in Irradiated Chest Wall Tissues

Background: Autologous fat grafting is increasingly used in irradiated postmastectomy tissues, but objective imaging-based data describing structural remodeling remain limited. Objective: This pilot study aimed to evaluate ultrasound detectable structural changes following autologous fat grafting in irradiated postmastectomy chest wall tissues. Methods: This prospective pilot study included five female patients with prior radical mastectomy and adjuvant chest wall radiotherapy who underwent a single-session of autologous fat grafting. High-resolution ultrasound was performed preoperatively and at 3-5 months postoperatively using a 12 MHz linear probe. Parameters evaluated included hypodermal thickness, echogenicity (hyperechoic versus hypoechoic patterns), fascial definition, and fibrotic patterns. Results: All patients demonstrated a consistent postoperative increase in hypodermal thickness. Preoperative compact, hyperechogenic architecture transitioned to heterogeneous hypoechogenic patterns suggestive of viable adipose tissue integration consistent with viable adipose tissue. Fascial planes became more clearly defined in four patients. No necrosis, oil cysts, or fluid collections were detected. Conclusions: In this pilot cohort, ultrasound detected consistent postoperative changes in hypodermal thickness, echogenicity, and fascial definition following autologous fat grafting. These findings support the feasibility of ultrasound for the non-invasive assessment of post-radiotherapy structural tissue changes.