Bioimpedance spectroscopy (BIS) is better than a tape measure for assessing a woman’s risk for developing lymphedema, painful swelling in the arm after breast cancer surgery, according to interim results of a study led by Sheila Ridner, PhD, RN, Martha Ingram Professor and director of the PhD in Nursing Science Program at Vanderbilt University School of Nursing.
Assessing a woman’s risk
The multisite international study compares the two methods for identifying women who should be prescribe compression sleeves and gauntlets to reduce lymphatic fluid in the arm and prevent progression to lymphedema. BIS surveillance reduce rates of progression by approximately 10%; a clinically meaningful improvement. Interim findings from the study are publish May 3 in Annals of Surgical Oncology and Ridner presented the analysis during the annual meeting of The American Society of Breast Surgeons in Dallas.
“The bioimpedance device measures lymphatic fluid, and the tape measures much more than that;” said Ridner, a researcher with Vanderbilt-Ingram Cancer Center. “It takes more lymphatic fluid to make your whole arm volume change than it does to make the device pick up changes. The device is just more sensitive to changes in lymphatic fluid.”
Measures lymphatic fluid
Breast cancer-related lymphedema affects between 20% and 30% percent of women due to damage to the lymph glands from surgery; radiation and some medicines, Ridner said. Lymphedema not only causes swelling in the arm; it can be physically debilitating and puts women at greater risk for infections as well as psychological stress.
The results are an interim analysis of an ongoing controlled trial called PREVENT, launched in 2014 and led by Ridner. The analysis involve 508 participants who had been monitor for a year or longer. Participants identify at risk for lymphedema receive compression sleeves and gauntlets and were instructed to wear them 12 hours daily for 28 days to prevent progression to lymphedema.
Patients who developed lymphedema reached their endpoint with the trial and were referred to clinicians for complex decongestive physiotherapy (CDP). “CDP is resource intensive and costly;” Ridner said. Because “Lymphedema therapists are not accessible everywhere and mostly are in metropolitan areas. You go an hour-and-a-half in any direction outside of Nashville; for example; and we can’t find people to treat these patients.”
Complex decongestive physiotherapy
Clinicians have traditionally used tape measures to monitor breast cancer patients for lymphedema; but that method can vary greatly depending upon how a clinician does this. “Tape measure is the most commonly use method around the world even though it is fraught with error,” Ridner says.
“To get accurate measurements for a research study, there is an incredible amount of training to teach all the sites in this international study how to measure the same way. I do annual fidelity oversight visits to every single site to make sure there has not been any slippage in the protocol.“