BackgroundThe use of immediate breast reconstruction and adjuvant radiation therapy is increasing in breast cancer patients. This study aimed to analyze the aesthetic outcome and changes in flap volume in patients with breast cancer undergoing radiation therapy of the surgical site after immediate autologous tissue reconstruction.MethodsImmediate abdominal free flap breast reconstruction following unilateral mastectomy was performed in 42 patients; 21 patients received adjuvant radiation (study group) and 21 patients did not (control group). To compare flap volume, three-dimensional computed tomography (CT) was performed before and after radiation. Also, aesthetic analysis was performed in both groups to evaluate shape changes.ResultsThere was a 12.3% flap volume reduction after the completion of radiation in the experimental group that was significantly greater than the 2.6% volume reduction observed in the non-radiation group (P<0.01). There was no significant difference in the short- and long-term aesthetic results between the groups.ConclusionsWhen performing immediate autologous breast reconstruction, 14% volume overcorrection is recommended for patients in whom adjuvant radiation therapy is anticipated to improve aesthetic outcomes.