Background: We previously devised an ultrasonographic evaluation to calculate subcutaneous tissue cross-sectional area (△CSA). The reliability and accuracy of this method were demonstrated in healthy individuals and in patients with lymphedema. The purpose of this study was to estimate the optimal cut-off value of the ratio of the △CSA of the involved side (lesion side) to the contralateral side for detecting breast cancer-related lymphedema (BCRL) using ultrasonography. Methods and Results: Ultrasonographic measurements were performed 290 times in 150 patients. BCRLD was defined as a confirmed difference of >2 cm in arm circumference. BCRL confirmed by a clinician (BCRLC) was defined as the patient group that included not only BCRLD but also patients with subcutaneous thickening and abnormal findings on lymphoscintigraphy, even if the difference in arm circumference was <2 cm. The △CSAs of both upper arms and forearms were calculated by measuring the thickness of the subcutaneous tissue at four locations using ultrasonography (superior, medial, inferior, lateral) at 10 cm above the elbow and 10 cm below the elbow. With a 1.35 △CSA ratio as the cut-off value for detecting BCRLD, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were 0.88, 0.87, and 0.95, respectively. With a 1.20 △CSA ratio as the cut-off value for detecting BCRLC, the sensitivity, specificity, and AUC were 0.92, 0.89, and 0.97, respectively. Conclusions: Our findings suggest that a 1.20 △CSA ratio as determined using ultrasonography, corresponding to a tape measurement of 1.05 cm, can be considered as a diagnostic criterion for lymphedema.

中文翻译：

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使用超声检查检测乳腺癌相关淋巴水肿的最佳截止值。

背景：我们之前设计了一种超声评估来计算皮下组织横截面积（△CSA）。该方法的可靠性和准确性已在健康个体和淋巴水肿患者中得到证实。本研究的目的是估计超声检查检测乳腺癌相关淋巴水肿（BCRL）时受累侧（病灶侧）与对侧的△CSA比值的最佳截断值。方法和结果：对 150 名患者进行了 290 次超声检查。BCRLD 被定义为已确认的臂围差异>2 厘米。经临床医生证实的BCRL（BCRLC）定义为不仅包括BCRLD，还包括皮下增厚且淋巴闪烁显像异常的患者，即使臂围差异<2cm。通过超声测量肘上10cm和肘下10cm四个位置（上、中、下、外侧）的皮下组织厚度，计算出双上臂和前臂的△CSA。以1.35△CSA比值作为检测BCRLD的临界值，敏感性、特异性和受试者工作特征曲线下面积（AUC）分别为0.88、0.87和0.95。以1.20△CSA比值作为检测BCRLC的截断值，敏感性、特异性和AUC分别为0.92、0.89和0.97。结论：我们的研究结果表明，超声检查确定的 1.20 △CSA 比率（相当于卷尺测量 1.05 cm）可被视为淋巴水肿的诊断标准。