The Role of Bioimpedance Spectroscopy in Standardizing Lymphedema Clinical Pathways

Steven Chen, MD, MBA and Chief Medical Officer of ImpediMed

Lymphedema is a frequently overlooked complication affecting cancer survivors, occurring when normal lymphatic drainage is disrupted, leading to the buildup of protein-rich lymph fluid in the interstitial space. If left untreated, it can evolve into a chronic condition, compromising patients' immune systems and increasing their susceptibility to infections.

According to the American Cancer Society, 58% of cancer patients diagnosed with breast cancer, melanoma, or pelvic area cancers are at risk for developing limb lymphedema, with over 80% of patients with breast cancer at risk. Breast cancer-related lymphedema (BCRL) affects up to 20% of patients with breast cancer. The prevalence varies depending on the nature and aggressiveness of the treatments received.

Lymphedema significantly impacts patients' quality of life, causing reduced physical functioning, hindered ability to perform daily activities, and heightened psychological distress. It also carries substantial economic consequences, with treatment costs over a two-year period ranging from $14 877 to $23 167. As a result, patients with advanced lymphedema face both physical discomfort and significant financial strain. Early detection and management are crucial to prevent progression. Implementing bioimpedance spectroscopy (BIS) as part of a comprehensive lymphedema prospective model of care can help standardize clinical pathways, reduce clinical variability, and improve patient outcomes compared to traditional tape measurements.

Challenges in Early Lymphedema Detection

Early detection of breast cancer-related lymphedema (BCRL) poses a significant challenge, as a lymphedema diagnosis typically occurs following visible symptoms or clinical changes. However, the phase preceding symptom manifestation, characterized by an increase in extracellular fluid, represents a critical window for early intervention to prevent the progression to chronic BCRL.

Educating patients about lymphedema risks, early indicators, and preventative actions is crucial yet often overlooked. Traditional BCRL detection methods have included volume assessments through tape measurements, displacement tanks, and volume estimation. However, the inconsistency of tape measurements associated with clinician variability and the late detection by volume-based methods have been problematic.

BIS as an Improved Detection Tool

Bioimpedance gives us the ability to monitor changes in bodily tissues in a noninvasive way. The body’s tissues all have varying levels of electrical conductivity. Muscle is more conductive than fat, and bone is non-conductive. By sending a low-level alternating electrical current through the body, BIS technology can measure the resistance and reactance to this electrical current–or bioimpedance.

Bioimpedance can be measured at different frequencies, which can be useful for measuring various compartments such as extracellular fluid and intracellular fluid. BIS, the most advanced method, emerges as a pivotal BCRL detection and management tool. This non-invasive, cost-effective technology accurately assesses body water and fluid volumes within tissues by measuring electrical impedance, offering valuable insights for early lymphedema detection. It utilizes a spectrum of 256 frequencies, ranging from 3 KHz to 1000 KHz, facilitating precise measurements of fluid and tissue volumes with clinical accuracy.

By using Cole plot modeling and the Hanai Mixture Theory, BIS enables clinicians to accurately measure extracellular fluid and total body water, which helps determine intracellular fluid, fat mass, and fat-free mass without population-specific regression-based algorithms. BIS enables earlier detection compared to tape measurements by being more sensitive to small fluid changes and differentiating intracellular vs extracellular fluid. The recommended BIS monitoring schedule for high-risk patients involves establishing a baseline measurement before starting treatment and measuring at regular intervals—every three months for three years, every six months for an additional two years, and then once a year after that. By using BIS at these intervals, lymphedema can potentially be detected early enough to treat it in most cases before tape measurements would identify a change. A large, randomized study demonstrated a significant reduction in progression to chronic lymphedema when utilizing BIS as compared to tape measurements.

Impact of Implementing BIS on Lymphedema Management

Implementing BIS facilitates regular, objective lymphedema assessments, enabling risk stratification and earlier referral to treatment when needed. This allows more efficient utilization of limited lymphedema therapy resources by focusing on patients who need treatment. Appropriate use of physical therapy coupled with early detection through BIS is expected to reduce the likelihood of chronic lymphedema compared to tape measure. Potential cost savings for both patients and physicians can be realized from preventing progression to chronic lymphedema, which requires costly lifelong care.

BIS as Part of a Prospective Model of Care

BIS is recognized in various national and international guidelines as an objective measurement tool to detect early signs of lymphedema. Educating patients and providers about the importance of early detection is key. The pathway to broader BIS adoption is unfolding as awareness of supporting data grows, alongside increasing reimbursement through Medicare, national, and regional private payors. This progress is further bolstered by legislative advancements like the Lymphedema Treatment Act and best practice recommendations for seamless integration into clinical workflows. BIS enables a standardized pathway for lymphedema monitoring and early intervention that is easily taught, executed, and reproducible compared to tape measurements, though some clinical judgment is still required to interpret results.

Ongoing research is using BIS to study treatment outcomes and evaluate emerging surgical interventions for lymphedema. There is growing interest in applying BIS to other cancers and causes of lymphedema beyond breast cancer, such as melanoma and gynecologic cancers. BIS can be a valuable tool for research across a variety of diseases and treatments where lymphedema presents a problem.

BIS offers significant value in enabling a proactive, preventive approach to lymphedema care as part of a comprehensive prospective surveillance model. By facilitating earlier detection and intervention compared to traditional methods, BIS has the potential to improve patient outcomes, reduce clinical variability, and decrease healthcare costs associated with chronic lymphedema.

About the Author

Steven Chen, MD, MBA, serves as the Chief Medical Officer of ImpediMed, a pioneer in the field of medical technology. He has also served as the Chief of Breast Surgery at UC Davis Medical Center, followed by a position as an Associate Professor of Surgery and as the associate program director of the surgical oncology training program at City of Hope National Medical Center in Duarte, California. Dr. Chen is a past President of the American Society of Breast Surgeons and serves on committees for a number of professional societies including the American Medical Association, the Society of Surgical Oncology, and the American College of Surgeons. He is also a practicing surgeon in San Diego, California, and the Director of Surgical Oncology at OasisMD.