Bioimpedance Spectroscopy May Play a Large Role in Proactively Preventing Chronic Lymphedema

Sheila H. Ridner, PhD, RN, FAAN

Bioimpedance spectroscopy (BIS) is a more accurate method of identifying which breast cancer survivors will need compression intervention for subclinical lymphedema compared with tape measurement (TM) to prevent chronic lymphedema, according to findings from a study published in Lymphatic Research and Biology.¹ Moreover, the technology is easy to use and patient friendly, according to principal investigator Sheila H. Ridner, PhD, RN, FAAN.

“It is as easy to use as putting someone on a scale and getting their weight,” Ridner, research professor at Vanderbilt University School of Nursing in Nashville, Tennessee, explained in an interview with Oncology Nursing News®, noting that the underlying technology is based on electrical currents that measure the fluid between the cells. “It’s very simple. It’s very quick.”

Results from the PREVENT study (NCT02167659) showed that among patients who received compression intervention after early lymphedema detection, only 7.9% of patients who were assessed through BIS developed chronic lymphedema. In comparison, 19.2% of patients who were assessed using TM developed this chronic disease. These statistically significant results (P = .016) may translate into an absolute reduction of 11.3% and a relative reduction of 59% in lymphedema progression at 3 years, according to the study authors.

Chronic breast cancer–related lymphedema (C-BCRL) has become more concerning as the rate of breast cancer survivorship has continued to rise. As such, the number of patients affected by pain, infections, limited arm function, reduced quality of life, and very expensive therapies because C-BCRL has likely grown in recent years.

“To me, it is [a] numbers game,” Ridner said. “More survivors equal more opportunity for chronic pain…but if we can keep people from getting it, then there is a whole set of lymphedema-related pain issues breast cancer survivors may be able to avoid.” Currently, 5% of patients who undergo breast-conserving surgery with sentinel lymph node biopsy (SLNB) alone experience C-BCRL, as well as more than 50% of patients who undergo axillary lymph node dissection, regional node irradiation, and/or taxane-based chemotherapy. These statistics underscore the value of proper C-BCRL identification in breast cancer survivors, the authors explained. However, early-stage C-BCRL identification can be challenging.

Although subclinical disease and extracellular fluid occurs before changes become visible, C-BCRL diagnoses do not typically occur until a visible change or symptom has become apparent. Therefore, investigators decided to use BIS to identify early-stage subclinical lymphedema and to initiate treatment to prevent C-BCRL (defined as ≥ 10% arm volume change from baseline, requiring complex decongestive physiotherapy CDP) in survivors. BIS technology can recognize extracellular fluid change and has been found to improve patient outcomes when combined with short-course compression therapy, as was administered in this study.

“The BIS can pick up changes in the fluid that exists between each human cell. [TM] can’t do that, pyrometry can’t do that, and MRI can’t do that,” Ridner said. “The earlier you catch this fluid, the less likely you are to have a large inflammatory process in the arm. We are now able to identify the subclinical lymphedema when there is less inflammation that needs to be treated.”

The stratified, randomized, international trial included patients with recent breast cancer diagnoses who were undergoing either mastectomy/partial mastectomy, axillary treatment (dissection, SLNB > 6 nodes or radiation), radiation therapy, or taxanebased therapy. Exclusion criteria included history of breast cancer, neoadjuvant chemotherapy, and previous radiation on the breast, chest wall, or axilla.

Participants were randomized 1:1 following a postsurgery eligibility reassessment and underwent prospective surveillance via either BIS or TM. If surveillance detected C-BCRL, patients were to wear a class 2 (23-32 mm Hg, mediven flat-knit custom or Harmony circular knit) compression sleeve and gauntlet for 12 hours per day for 4 weeks.

Patients were recruited between June 24, 2014, and September 11, 2018. In total, 442 evaluable patients were enrolled in the BIS cohort, and 437 evaluable patients were enrolled in the TM cohort. The median follow-up was 32.9 months.

Presurgical measurements were collected at baseline for both the BIS or TM cohorts; collected again at 3, 6, 12, 18, 24, and 36 months; and again following compression intervention. Some sites also conducted a 15- and 21-month follow-up.

The BIS evaluation was conducted via L-Dex U400, and TM evaluation was conducted using Gulick II tape. The patients’ arms were measured twice at 10-cm increments, starting at the wrist and continuing up to 50 cm above the wrist. A truncated cone formula was used to automatically calculate arm volume. Ultimately, the number of patients whose disease progressed following compression intervention was lower in the BIS group than the TM group (7.9%, n = 7 vs 19.2%; n = 23, relative risk, 0.41; 95% CI, 0.13-0.81; absolute reduction 11.3%; 95% CI, 2.3-20.3; P = .016).

Notably, Ridner’s patients have expressed satisfaction with the technology. “The first patient I ever measured [with BIS] loved the technology,” she said. “Patients can tell [TM] techniques vary from therapist to therapist, doctor to doctor, or nurse to nurse. [BIS] standardizes the way you do the measurement.”

“Surveillance with early intervention is clearly in the best interest of the patients,” Ridner said. “We can change outcomes in this population and address not only the chronicity of the lymphatic issues many of these patients have but also reduce the discomfort they may experience.”

References

1. Ridner SH, Dietrich MS, Boyages J, et al. A comparison of bioimpedance spectroscopy or tape measure triggered compression intervention in chronic breast cancer lymphedema prevention. Lymphat Res Biol. 2022;10.1089/lrb.2021.0084. doi:10.1089/lrb.2021.0084