Risk Factors for the Development of Clinical and Subclinical Lymphedema Detected by Bioimpedance Spectroscopy

Background: Breast cancer-related lymphedema can significantly compromise quality of life. Bioimpedance spectroscopy (BIS) measures extracellular fluid in lymphedema. The purpose of this study was to determine the incidence of BIS-detected lymphedema using the L-Dex and identify risk factors associated with a positive score. Materials and Methods: We performed a retrospective review of our institutional database to identify patients who underwent L-Dex U400 measurements. Patients with a score of > 10 L-Dex units or with an increase of > 10 units from baseline had a positive score. Clinical lymphedema was determined by documentation in the chart at the time of positive measurement. Otherwise, patients were considered to have subclinical lymphedema. Results: Fifty-three patients met study cr iter ia. Thirty patients (56.6%) underwent mastectomy, 22 (41.5%) axillary lymph node dissection (ALND), and 33 (62.3%) received radiation (RT). Twelve patients (22.6%) had a positive score. There were no differences in age, race, laterality, breast surgery, T stage, N stage, chemotherapy, or RT fields (none, breast only, breast with LNs) in patients with a positive score. ALND was more common (66.7% vs. 34.2%, P = .04). BMI > 30 approached significance (58.3% vs. 29.3%, P = .06). Seven patients had subclinical lymphedema. No differences were identified comparing patients with subclinical lymphedema to those with negative scores. All 5 patients with clinical lymphedema underwent ALND and received nodal RT. Conclusion: The combination of ALND and regional nodal RT is strongly associated with development of clinical lymphedema. It is difficult to identify patients at risk for subclinical BIS-detected lymphedema.