Diagnosing Lymphedema after Axillary Surgery: A Prospective Comparison of Bioimpedance, Tape Measurement, and Perometer in Patients Treated with Axillary Lymph Node Dissection.

OBJECTIVE:This study prospectively compared lymphedema rates with perometer, tape measure, and bioimpedance spectroscopy (L-Dex) in patients with breast cancer undergoing axillary lymph node dissection (ALND). BACKGROUND:Perometer, tape measure, and L-Dex are all used for diagnosing lymphedema, although lymphedema rates may vary between these techniques. METHODS:From November 2016 to March 2020, patients who underwent ALND had arm measurements performed preoperatively and biannually with perometer, tape measure, and L-Dex. A lymphedema diagnosis was made if arm volume increased by ≥10% by perometer or tape measure, or if L-Dex increased ≥6.5 units from baseline. We assessed concordance between the different measurement techniques using scatter plots, Pearson correlations, and Cohen's Kappa statistic. RESULTS:We included 281 patients who underwent ALND and had at least one follow-up (median, 2.3 years; >1100 follow-up measurements). Two-year lymphedema rates were 21.9% with perometer, 34.6% with tape measure, and 67.5% with L-Dex. Evaluating all timepoints, we found moderate correlation between perometer and tape measure (R=0.67, P<0.001), perometer and L-Dex (R=0.66, P<0.001) and tape measure and L-Dex (R=0.57, P<0.001). Diagnostic agreement was weak between perometer and L-Dex (k=0.29, P<0.001), and tape measure and L-Dex (k=0.28, P<0.001); and moderate between perometer and tape measure (k=0.51, P<0.001). CONCLUSION:In our prospective ALND cohort, perometer, tape measure, and L-Dex demonstrated moderate correlation between measurements, and weak-to-moderate diagnostic agreement. Lymphedema rates varied between measurement techniques, with the highest rates observed with L-Dex, raising concern for overdiagnosis.