BREAST-V Versus MRI for Breast Volume Assessment Before and After Breast Asymmetry Surgery: Good Preoperative Association but Limited Postoperative Interchangeability.

BACKGROUND: Objective breast volume measurement is critical for breast asymmetry surgery. BREAST-V is a practical anthropometric formula, but its interchangeability with MRI, particularly after surgery, is unclear. OBJECTIVES: To evaluate agreement between BREAST-V and MRI before and after breast asymmetry surgery. METHODS: Forty patients underwent preoperative and postoperative MRI and BREAST-V assessments. Agreement was evaluated using ICC, Bland-Altman analysis, and error metrics. Intraoperative field changes were recorded, an MRI-based MCID was derived using distribution-based methods, and satisfaction was assessed with BREAST-Q. RESULTS: Preoperatively, BREAST-V showed good association and moderate agreement with MRI (ICC = 0.788; r = 0.840; p < 0.001). Postoperatively, agreement was poor (ICC = 0.210; r = 0.339; p = 0.032). Bland-Altman bias increased from +69.5 mL preoperatively to +279.2 mL postoperatively, with wide limits of agreement (-366.4 to +505.5 mL and -67.2 to +625.7 mL, respectively). Error metrics showed clinically relevant divergence, particularly postoperatively (mean absolute error, 177.6 vs 280.5 mL; mean absolute percentage error, 35.5% vs 41.0%). The MRI-derived MCID for asymmetry was 92.5 mL. Among 30 patients with paired BREAST-Q data, Satisfaction with Breasts improved from 25.0 ± 24.1 to 81.0 ± 12.7 points (mean improvement, 56.0; 95% CI, 46.4-65.6; p < 0.001). CONCLUSIONS: BREAST-V may be useful for preoperative planning but should not be considered interchangeable with MRI after surgical remodeling.