Normative Interlimb Impedance Ratios: Implications for Early Diagnosis of Uni- and Bilateral, Upper and Lower Limb Lymphedema

Comparison of Volume Measurements and Bioimpedance Spectroscopy Using A Stand-on Device for Assessment of Unilateral Breast Cancer-Related Lymphedema

Objective

Breast cancer related lymphedema (BCRL) may be assessed through objective measurement of limb swelling with common techniques including volumetric measurement using a tape measure or perometry, and measurement of extracellular water using bioimpedance spectroscopy (BIS). This study aimed to evaluate the performance of a stand-on BIS device for detection of BCRL, introduce a novel graphical method to compare volumetric and BIS methods alongside traditional specificity and sensitivity analysis, and determine and compare BIS thresholds with those published previously.

Materials and Methods

Female participants with indocyanine green lymphography confirmed unilateral arm lymphedema (n = 197) and healthy controls (n = 267) were assessed using a cross-sectional study design. BIS and volumetric measures were obtained in a single session.

Results

The BIS lymphedema index (L-Dex) method had a significantly higher sensitivity than the excess volume approach (area under the curve = 0.832 vs. 0.649, p = 0.0001). A threshold of L-Dex 6.5 had a higher true positive rate (70.6%) than L-Dex 10 (68.5%) although false positive rate increased from 0.4% to 2.6%. A threshold of 5% excess volume improved the true positive rate (68.5%) compared with 10% excess volume (49.7%) however the false positive rate increased to an unacceptable 47%. The L-Dex ranges in this study were not significantly different from previously published ranges.

Conclusion

BIS was superior for identifying BCRL compared with volume measurements, reaffirming the value of this technique. However, it is recommended that BIS be used in conjunction with comprehensive evaluation of symptoms and clinical presentation. The proposed graphical method provides a simple and easily interpretable approach to compare and define concordance between the two commonly used methods for BCRL assessment namely limb volume and BIS L-Dex indices. The existing BIS (L-Dex) thresholds for presence of BCRL were also validated.

Effects of Body Positioning When Assessing Lymphedema of the Lower Limb Using Bioimpedance Spectroscopy

Background: Bioimpedance spectroscopy (BIS) measurements are conventionally performed in supine position with a lead device attached to gel-backed electrodes, and more recently, with a stand-on device that uses fixed stainless-steel electrodes under the hands and feet. The aim of this study was to assess and compare BIS measurements made in supine, sitting, and standing positions using lead and stand-on impedance devices in participants with and without unilateral leg lymphedema. Materials and Methods: Participants with self-ascribed unilateral leg lymphedema (n = 24) and healthy controls (n = 71) were recruited using a cross-sectional study design. Triplicate BIS measurements were taken for each device in each position. Results: Impedance measurements with either device were reliable with coefficient of variation of 0.6% or lower. The magnitude of mean differences in absolute impedance values between devices were between 1% and 6% dependent on condition. L-Dex scores between the two devices were highly correlated (r = 0.82) and ∼70% of participants in the lymphedema group were classified as having lymphedema using the recommended cut-off with either device. There was no significant interleg difference of controls using the lead device; however, small, but significant differences (p = 0.0001) were found when using the stand-on device. Conclusion: The findings demonstrate that reliable impedance measurements of the legs can be made with either device in lying, sitting, or standing positions. However, data between the devices were not directly interchangeable. Although the risk of misidentification was small, reference ranges appropriate to the device and measurement position should be used when converting data to L-Dex scores.

A Prospective Preliminary Study Examining the Physiological Impact of Pneumatic Compression Dosing in the Treatment of Lower Extremity Lymphedema

Background: Optimal frequency and duration of pneumatic compression device (PCD) therapy for lymphedema is undetermined. This prospective, randomized preliminary study evaluated the impact of different PCD dosing protocols on physiological and patient-reported outcomes (PROs) to estimate treatment effects, assess the responsiveness of various measurement techniques, and identify endpoints for a definitive PCD dosing trial. Methods and Results: Twenty-one patients with lower extremity lymphedema were randomized into three groups for treatment with the Flexitouch advanced PCD: (A) once per day for 1 hour, 12 consecutive days; (B) twice per day in 1-hour treatments, 5 consecutive days; or (C) twice per day in 2-hour treatments, 5 consecutive days. Outcomes measured were changes in limb volume (LV), tissue fluid, tissue tone, and PROs. Those in group A experienced mean (standard deviation) LV reductions of 109 (58) mL (p = 0.003) on day 1 and of 97 (86) mL (p = 0.024) on day 5. Group A also showed possible single-treatment decreases in extracellular fluid volume by bioimpedance spectroscopy (BIS) on day 5. There were no consistent changes in groups B and C. Long-term assessment of LV and BIS showed no clear change. Tonometry, ultrasound, local tissue water, and PROs showed wide variation among participants. Conclusions: LV measurements showed potential benefit for 1-hour daily PCD treatment. A definitive dosing trial should include LV, BIS, and PROs in a comparison of 1- and 2-hour daily treatment protocols conducted over a study period of 4 weeks. These data may inform appropriate outcome measures for other intervention studies in lymphedema.

A Low-Cost, Portable, and Mobile-Based Bioimpedance Lymphedema Diagnosis and Monitoring System (Mobilymph): A Validation Study

Background: Breast cancer-related lymphedema (BCRL) is a debilitating chronic illness. Early management and prevention of disease progression rely on lymphedema monitoring and assessment. At present, lymphedema monitoring systems are costly and do not promote remote monitoring. Thus, a low-cost, portable, mobile-based bioimpedance lymphedema monitoring system (Mobilymph) was developed to ensure continuous lymphedema surveillance. Method and Results: Forty-five healthy and 100 BCRL participants were recruited in this study. Mobilymph bioimpedance measurement was validated with a Quadscan 4000 on healthy participants' arms. The interarm bioimpedance ratio was determined to evaluate the discriminatory capability of Mobilymph to detect BCRL. Mobilymph's bioimpedance results show no significant difference compared to Quadscan 4000. The interarm bioimpedance ratios were significantly different (p < 0.001), between participants in healthy and Stage 1, Stage 0 and Stage 1, and Stage 1 and Stage 2. Healthy and Stage 0 participants had similar interarm impedance ratios (p = 0.63). Conclusion: The bioimpedance results show that Mobilymph bioimpedance measurement is comparable to Quadscan 4000 and can detect BCRL arms. Thus, Mobilymph lymphedema monitoring system offers a feasible solution for early lymphedema diagnosis and treatment monitoring. Clinical trial registration number: MREC ID No.: 2020316-8181.

Exercise during CHemotherapy for Ovarian cancer (ECHO) trial: design and implementation of a randomised controlled trial

INTRODUCTION

Epidemiological evidence supports an association between higher levels of physical activity and improved cancer survival. Trial evidence is now needed to demonstrate the effect of exercise in a clinical setting. The Exercise during CHemotherapy for Ovarian cancer (ECHO) trial is a phase III, randomised controlled trial, designed to determine the effect of exercise on progression-free survival and physical well-being for patients receiving first-line chemotherapy for ovarian cancer.

METHODS AND ANALYSIS

Participants (target sample size: n=500) include women with newly diagnosed primary ovarian cancer, scheduled to receive first-line chemotherapy. Consenting participants are randomly allocated (1:1) to either the exercise intervention (plus usual care) or usual care alone, with stratification for recruitment site, age, stage of disease and chemotherapy delivery (neoadjuvant vs adjuvant). The exercise intervention involves individualised exercise prescription with a weekly target of 150 minutes of moderate-intensity, mixed-mode exercise (equivalent to 450 metabolic equivalent minutes per week), delivered for the duration of first-line chemotherapy through weekly telephone sessions with a trial-trained exercise professional. The primary outcomes are progression-free survival and physical well-being. Secondary outcomes include overall survival, physical function, body composition, quality of life, fatigue, sleep, lymphoedema, anxiety, depression, chemotherapy completion rate, chemotherapy-related adverse events, physical activity levels and healthcare usage.

ETHICS AND DISSEMINATION

Ethics approval for the ECHO trial (2019/ETH08923) was granted by the Sydney Local Health District Ethics Review Committee (Royal Prince Alfred Zone) on 21 November 2014. Subsequent approvals were granted for an additional 11 sites across Queensland, New South Wales, Victoria and the Australian Capital Territory. Findings from the ECHO trial are planned to be disseminated via peer-reviewed publications and international exercise and oncology conferences.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trial Registry (ANZCTRN12614001311640; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=367123&isReview=true).

Clinical Utility of Bioelectrical Impedance Analysis Parameters for Evaluating Patients with Lower Limb Lymphedema after Lymphovenous Anastomosis

BACKGROUND

 In lymphedema, lymphatic fluid accumulates in the interstitial space, and localized swelling appears. Lymphovenous anastomosis (LVA) is the most widely used surgery to rebuild a damaged lymphatic system; however, assessing outcome of LVA involves performing volume measurements, which provides limited information on body composition changes. Therefore, we analyzed the bioelectrical impedance analysis (BIA) parameters that can reflect the status of lymphedema patients who underwent LVA.

METHODS

 We retrospectively reviewed records of 42 patients with unilateral lower extremity lymphedema who had LVA. We measured the perioperative BIA parameters such as extracellular water (ECW) ratio and volume as defined by the percentage of excess volume (PEV). We evaluated the relationship between the amount of change in PEV and in BIA parameters before and after surgery. We confirmed the correlation between ΔPEV and BIA parameters using Spearman's correlation.

RESULTS

 Most patients included had secondary lymphedema due to cancer. Average age was 51.76 years and average body mass index was 23.27. PEV and all BIA parameters after surgery showed a significant difference (p < 0.01) compared with preoperative measurements. The ECW ratio aff/unaff showed the strongest correlation with PEV with a correlation coefficient of 0.473 (p < 0.01).

CONCLUSION

 Our findings suggest that BIA parameters, especially ECW ratio aff/unaff could reflect the status of patients with lower limb lymphedema after LVA. Appropriate use of BIA parameters may be useful in the postoperative surveillance of patients.

Bioimpedance basics and phase angle fundamentals

Measurement of phase angle using bioimpedance analysis (BIA) has become popular as an index of so-called "cellular health". What precisely is meant by this term is not always clear but strong relationships have been found between cellular water status (the relative amounts of extra- and intracellular water), cell membrane integrity and cellular mass. Much of the current research is empirical observation and frequently pays little regard to the underlying biophysical models that underpin the BIA technique or attempts to provide mechanistic explanations for the observations. This brief review seeks to provide a basic understanding of the electrical models frequently used to describe the passive electrical properties of tissues with particular focus on phase angle. In addition, it draws attention to some practical concerns in the measurement of phase angle and notes the additional understanding that can be gained when phase angle are obtained with bioimpedance spectroscopy (BIS) rather than single frequency BIA (SFBIA) along with the potential for simulation modelling.

Three Decades of Bioelectrical Impedance Spectroscopy in Lymphedema Assessment: An Historical Perspective

Bioelectrical impedance spectroscopy (BIS) is a technology that is widely used for the assessment of body composition. The method is based on the measurement of the electrical resistance of the body or a body region that can be quantitatively related to the amount of water in the tissues. Lymphedema is characterized, at least in its early stages, as an accumulation of lymph, an extracellular fluid. In the late 1980s, it was recognized that it might be possible to adapt BIS protocols to measure this increase in lymph volume. Subsequently, the use of BIS for the early detection of breast cancer-related lymphedema was demonstrated in the early 1990s, with BIS reference values indicative of lymphedema published in 2001. The subsequent two decades have seen BIS become a widely accepted method for lymphedema assessment. This review traces the evolution of the BIS technique since its inception and presents the current state of the art, with particular emphasis on utility in clinical practice.

Bioimpedance Spectroscopy of the Breast

Background: Bioimpedance spectroscopy (BIS) measurements of breast lymphedema poses practical and technical challenges, in particular the determination of the resistance at zero frequency (R₀), the index of change in breast lymph content. Conventionally, R₀ is calculated from data analysis by using a procedure eponymously known as Cole modeling, a method that is error-prone in the breast. The aim of this study was to evaluate polynomial curve fitting as an alternative analytic procedure. Methods and Results: A sub-set of breast BIS measurements from 41 women with self-ascribed breast lymphedema obtained as part of the Breast Edema Exercise Trial (BEET) were analyzed by both the Cole and polynomial methods. BIS files for all subjects were able to be analyzed by using the polynomial method but only 73% and 88% of data files were analyzed for the affected and unaffected breasts, respectively, by using the Cole method. For those files that were capable of being analyzed by both methods, R₀ values were highly correlated (r = 0.99) but with a small (1.6%) although statistically significant difference (paired t test, p < 0.001) between methods. Conclusions: Analysis of BIS data using polynomial curve fitting is an acceptable and robust alternative to Cole modeling, particularly where impedance measurements are susceptible to technical sources of error of measurement. The small magnitude of difference observed between methods is unlikely to lead to misclassification of patients with lymphedema based on BIS assessment.