Comments on "Breast Volume Measurements and Objectivations for Determination of Symmetry: A Retrospective Study in a Large Study Population".

Killaars et al. investigated the relationship between subjective breast symmetry assessment and objective three-dimensional (3D) volumetric measurements, providing valuable insights into aesthetic breast evaluation. However, several methodological limitations merit consideration. Although inter-observer agreement was reported, intra-observer reliability was not assessed, limiting evaluation of the consistency and reproducibility of subjective ratings. Furthermore, the study used breast volume difference as the objective reference standard despite breast symmetry being a multidimensional concept encompassing breast shape, contour, projection, nipple-areolar complex position, and inframammary fold alignment. Reliance on volumetric measurements alone may therefore underestimate overall aesthetic symmetry and partly explain the poor concordance with subjective assessments. In addition, while the introduction emphasizes the importance of symmetry for patient body image, the study population comprised individuals attending breast consultations rather than a truly healthy cohort, potentially limiting generalizability. More importantly, subjective evaluation relied exclusively on plastic surgeons and laypersons without incorporating patient-reported outcome measures. As patient satisfaction is the principal goal of aesthetic breast surgery, inclusion of validated instruments such as the BREAST-Q would have strengthened the clinical relevance of the findings. Finally, the absence of an a priori sample size or power calculation, the unexplained reduction from 209 eligible participants to 100 analysed cases, and agreement estimates based on only five plastic surgeons and five laypersons with wide confidence intervals raise concerns regarding the precision and reliability of the reported agreement. Future studies should integrate multidimensional symmetry metrics, patient-reported outcomes, intra-observer reliability, and adequately powered agreement analyses to enhance the validity and clinical applicability of breast symmetry assessment.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.