New criteria for breast symmetry evaluation after breast conserving surgery for cancer

ABSTRACT Objective: to evaluate symmetry after breast-conserving surgery (BCS) for cancer. Methods: a prospective study of patients undergoing BCS. These patients were photographed using the same criteria of evaluation. The references points used were the nipple height difference (NH), the nipple-manubrium distances (NM), nipple-sternum distances (NS) and the angle between the intramammary fold and the nipple (nipple angle; NA). ImageJ software was used. Three breast symmetry models were evaluated: excellent/others (model 1), excellent-good/others (model 2) and others/poor (model 3). The ROC curve was used to select acceptable criteria for the evaluation of symmetry. Decision tree model analysis was performed. Results: a total of 274 women were evaluated. The BCCT.core result was excellent in 5.8% (16), good in 24.1% (66), fair in 46.4% (127) and poor in 23.7% (65). The difference in NH was associated with good breast area (0.837-0.846); acceptable differences were below 3.1 cm, while unacceptable values were greater than 6.4 cm. Differences in the NM were associated with average breast area (0.709-0.789); a difference in value of less than 4.5 cm was acceptable, while values greater than 6.3 cm were unacceptable. In the decision tree combined model, a good-excellent outcome for patients with differential (d) dNH = 1 (0 to 5.30 cm) and dNM ≠ 3 (<6.28 cm); and for a poor/poor result, values dNM = 3 (> 6.35). Conclusions: the results presented here are simple tools that can assist the surgeon for breast symmetry evaluation.

摘要 目的：评估癌症患者接受保乳手术（breast-conserving surgery, BCS）后的乳房对称性情况。方法：本研究为一项针对接受保乳手术患者的前瞻性研究。所有患者均采用统一评估标准进行拍照。本次研究选取的参考指标包括：乳头高度差（nipple height difference, NH）、乳头-胸骨柄间距（nipple-manubrium distance, NM）、乳头-胸骨间距（nipple-sternum distance, NS）以及乳腺内褶皱与乳头间夹角（乳头夹角，nipple angle, NA）。研究采用ImageJ软件（ImageJ）进行数据分析，并对三种乳房对称性评估模型展开评估：模型1（优/其他）、模型2（优-良/其他）以及模型3（其他/差）。本研究采用受试者工作特征曲线（receiver operating characteristic curve, ROC）筛选适用于对称性评估的合格判定标准，并开展决策树模型分析。结果：本研究共纳入274名女性患者完成评估。经BCCT.core工具评估，结果为优者占5.8%（16例），良者占24.1%（66例），一般者占46.4%（127例），差者占23.7%（65例）。乳头高度差与乳房区域良好评分呈显著相关（相关系数区间为0.837~0.846），可接受的差值范围为≤3.1 cm，差值＞6.4 cm则判定为不合格。乳头-胸骨柄间距差值与乳房平均区域评分呈显著相关（相关系数区间为0.709~0.789），差值＜4.5 cm为可接受范围，差值＞6.3 cm则判定为不合格。在联合决策树模型中，当差值dNH=1（0~5.30 cm）且dNM≠3（＜6.28 cm）时，患者预后为优-良等级；而当dNM=3（＞6.35 cm）时，患者预后为差-差等级。结论：本研究所得结果为简便易用的评估工具，可辅助外科医师完成乳房对称性评估。