Diagnostic Accuracy of Clinical Measures Considering Segmental Tissue Composition and Volume Changes of Breast Cancer-Related Lymphedema

Eun Joo Yang, Seoung Yeon Kim, Woo Hyung Lee, Jae-Young Lim, and Jaebong Lee. Lymphatic Research and Biology, 2018

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Diagnostic Accuracy of Clinical Measures Considering Segmental Tissue Composition and Volume Changes of Breast Cancer-Related Lymphedema

Eun Joo Yang, Seoung Yeon Kim, Woo Hyung Lee, Jae-Young Lim, and Jaebong Lee. Lymphatic Research and Biology, 2018

Background: If we use only volumetry for measuring lymphedema, we could underdiagnose lymphedema with characteristics of biomechanical changes without definite volume change, especially in the medial forearm.

Methods and Results: In total, 158 breast cancer patients participated in this study. Arm volume was measured by water displacement volumetry, and segmental volumes were calculated from circumferences by using the truncated cone method. Subcutaneous ultrasound echogenicities were assessed on the medial side of the upper arm and forearm of both arms and graded by subcutaneous echogenicity grade (SEG) and revised SEG (rSEG). The standards for diagnosing secondary lymphedema were according to the volume change and clinical stage. Sensitivity, specificity, receiver-operating characteristic (ROC) curve, and area under the curve (AUC) were used. Analysis of ROC curves yielded AUCs of 0.875–0.933 (p<0.001). Volume differences in each segment were significantly different among the grades by SEG. The highest AUC was found for volume difference (AUC=0.919, 95% confidence interval [CI]=0.860–0.978) in the upper arm near the elbow; however, in the medial forearm, the highest AUC was found for rSEG (AUC=0.948, 95% CI=0.923–0.965 in the proximal forearm; AUC=0.940, 95% CI=0.923–0.965 in the distal forearm).

Conclusions: Our findings support the use of SEG by ultrasound in the assessment of lymphedema, especially in the medial region of the forearm. Subcutaneous ultrasound echogenicities may improve the accuracy of diagnosis of lymphedema in the forearm.

Main findings

  • Arm volume measurements (water displacement) were performed by using a graduated plastic cylinder.
  • Arm volumes of both affected and unaffected arms were also calculated from limb circumferences. Circumference measurements were performed with a tape measure beginning at1 4cm above,7cm above, 7cm below,14cm below, and at the level of the medial olecranon. The volume of each of the four arm segments was calculated from circumferences by using the formula for a truncated cone.
  • Arm segments were designated as segment A (7–14cm above the medial olecranon), segment B (at the level of to 7cm above the medial olecranon), segment C (at the level of to 7cm below the medial olecranon), and segment D (7–14cmbelow the medial olecranon).
  • ECF measurements by Bioelectrical impedance analysis (BIA). The impedances of the affected and unaffected arms were determined by using the Inbody S10 Biospace device (Model JMW140; Biospace Co. Ltd., South Korea).
  • The skin and subcutaneous tissue were scanned by using an ultrasound system fitted with an 11-MHz transducer. The scan points were as follows: 14cm above (A), 7cm above (B), 7cm below (C), and 14cm below (D) the medial olecranon of the medial part of the arm in the ventral position.
    • Grade 0: no increase in subcutaneous echogenicity relative to the contralateral side. The subcutaneous fat layer was black.
    • Grade 1: a diffuse increase in echogenicity relative to the contralateral side, but horizontal or obliquely oriented echogenic lines caused by connective tissue bundles can be clearly seen.
    • Grade 2: a diffuse increase in echogenicity relative to the contralateral side, skin, and subcutaneous layer can be divided by echogenicity, but echogenic lines cannot be seen.
    • Grade 3: a diffuse increase in echogenicity. Echogenic lines are not identifiable.
  • Medical record review. Patient characteristics, including age, level of education, income, job, side of dominance/ handedness, and treatment characteristics, including cancer stage, type of surgery, type of axillary procedure, and adjuvant therapy, including chemotherapy, radiotherapy, and hormone therapy.
  • Using ultrasonography, a relatively fast and reproducible method, subcutaneous echogenicity grade parameters were shown to be comparable to those obtained by calculating volume differences. Importantly, this study demonstrated that revised grade categorization of subcutaneous echogenicity was capable of identifying lymphedema, especially in the forearm.
  • In the forearm, soft tissue changes, indicating increased adiposity, assessed by ultrasonography, were more related to segmental volume change than the de facto gold standards, defined by the whole arm volume change and clinical stage.
  • The authors suggest their findings support the use of subcutaneous echogenicity grade by ultrasound in the assessment of lymphedema, especially in the medial region of the forearm. Subcutaneous ultrasound echogenicities may improve the accuracy of diagnosis and may be used to monitor lymphedema progress and severity in the forearm.
  • Longitudinal changes and analyses of treatment effects should be assessed comprehensively at all stages of lymphedema. A comprehensive standardized tool is needed.