Risk of Radiation-Induced Capsular Contracture following Subpectoral or Prepectoral Implant-Based Breast Reconstruction.

[BACKGROUND] Radiation therapy (RT) significantly increases the risk of capsular contracture after implant-based breast reconstruction. However, the relationship between anatomic plane placement (eg, submuscular or prepectoral) and the development of capsular contracture remains unclear. This study compared the risk of RT-induced capsular contracture in patients who underwent 2-stage prepectoral versus submuscular implant reconstruction.

[METHODS] The authors conducted a retrospective analysis of patients who underwent 2-stage implant reconstruction with radiation to the tissue expander between 2010 and 2024 at a single institution. Capsular contracture was evaluated and classified by the Baker scale. Patients with documented Baker II, III, or IV capsules were considered to have developed capsular contracture. Cox proportional hazards models were used to identify predictors of contracture, and Kaplan-Meier curves were used to estimate the cumulative incidence in prepectoral versus submuscular reconstruction.

[RESULTS] A total of 585 patients were included; 116 underwent prepectoral and 469 underwent submuscular implant placement. Capsular contracture occurred in 62% of submuscular and 18% of prepectoral cases ( P < 0.001). The estimated 48-month cumulative incidence of capsular contracture was 61% (95% CI, 56% to 65%) for submuscular and 35% (95% CI, 19% to 47%) for prepectoral reconstruction ( P < 0.001). Submuscular implant placement was associated with a significantly higher risk of developing capsular contracture over time than prepectoral reconstruction (hazard ratio, 3.00 [95% CI, 1.88 to 4.79]; P < 0.001).

[CONCLUSIONS] In the setting of RT, submuscular implant placement is associated with a significantly higher risk of capsular contracture compared with prepectoral placement. These findings emphasize the need for thorough patient counseling regarding the risks of capsular contracture and the importance of individualized reconstructive planning to optimize outcomes in patients undergoing radiation treatment.