Bioimpedance spectroscopy (BIS) technology could make difference.
Many cancer survivors, particularly those of breast, melanoma, and pelvic-area cancers, are susceptible to developing lymphedema — when clear lymphatic fluid builds up in the soft tissues of the body, usually in a limb, causing a painful and debilitating tightness and swelling.
Breast cancer survivors can be at particularly high risk for developing lymphedema and much of the recent research has been in this area. Breast cancer-related lymphedema (BCRL) affects approximately one in in five patients treated for breast cancer, and it has a significant negative impact on patients' quality of life after breast cancer treatment, serving as a constant reminder of the previous illness.
The majority of lymphedema cases are not diagnosed until they are already visually apparent — delaying proactive treatment before the condition worsens. Once chronic lymphedema has started, it cannot be cured.
Nevertheless, early and careful management can reduce symptoms and prevent it from getting worse. Several preventive and therapeutic options are available, both conservative and surgical, but are not included in most standardized intervention protocols. Keep in mind that any standardized prospective assessment is better than none at all. Different measures of arm volume, circumference, or edema with perometry, water displacement or a tape measure have been shown to be valid. The problem is that when diagnostic methods and staging systems lack uniformity, it can lead to a possible underestimation of the real incidence of lymphedema, decreasing early detection and the possibility of an effective treatment.
Fortunately, at a time when most physical therapists still rely on a tape measure to determine visible changes in lymphedema, modern medical technologies such as bioimpedance spectroscopy (BIS) are available to help to non-invasively measure, monitor and better manage this disease at a much earlier point.
The most promising technology is BIS, which enables clinicians to detect lymphedema earlier and improve treatment options and quality of life for cancer survivors. It also underscores the critical need to look at the body composition of cancer survivors, establish baseline conditions before surgery and conduct ongoing surveillance to track and manage lymphedema­­­.
This is where physical therapists can play a key role. Using BIS data points, they can help to lower the chances of misdiagnosis. Even without a pre-treatment baseline, BIS makes it possible to detect early signs of lymphedema, better understand body composition, and conduct ongoing surveillance of the condition.
Understanding the patient’s body composition using data is essential for addressing impairments of body function, structure, activity and participation restrictions and the impact of an exercise program that the patient may have stopped during cancer treatment.
Body mass index (BMI) is an imperfect measure of body fat and muscle. True body composition — not just weight -- needs to be considered when assessing a survivor’s general health. As a more direct measurement of body composition, BIS technology is a simple yet sophisticated device for measuring fluid status and tissue composition and should become a routine procedure in monitoring overall health.
BIS technology allows therapists to get back to basics in terms of understanding and quantifying cells and muscle mass. Going beyond the limitations of BMI, this technology gives clinicians the ability to track and manage their patient’s actual body fat, providing a clear, visual way to demonstrate progress, as well as to quantify improvements in skeletal-muscle mass or decreases in fat mass. Ultimately, this helps physical therapists to document the value of care and incentivize patients to continue a healthy lifestyle.
For cancer-related lymphedema, early screening is critical and yet the push for early detection is typically hampered by a variety of systemic issues within healthcare. A study that sought to determine the necessity of preoperative baseline in accounting for temporal changes of upper extremity volume concluded that the use of a postoperative proxy even early after treatment results in poor sensitivity for identifying BCRL. Providers with access to patients before surgery should consider the consequent need for pre-operative baseline.
Pre-treatment measurements and continued surveillance are essential for tracking early lymphedema. BIS technologies can provide a way to detect subclinical lymphedema and show changes in fluid status in extremities at the earliest possible stages to help guide the development of an effective survivorship program. Unfortunately, many physical therapists have limited access to BIS technology or may be unaware of the value of lymphedema surveillance and pre-treatment baseline screening.
Nevertheless, current literature strongly advocates for a prospective surveillance model as the best approach to preventing persistent, chronic lymphedema. An important clinical study, the PREVENT trial, looked at how well BIS could detect early signs of lymphedema compared with a tape measure, the traditional approach to measuring lymphedema onset or progression. It demonstrated that 95% of breast cancer-related lymphedema progression is preventable with routine surveillance using BIS followed by at-home treatment with standard compression therapy.
Consider this real-world example: A patient with a history of cervical cancer and secondary lymphedema had recently undergone a surgery to control her lymphedema with lymphatic surgery and wanted to get back into a shape for a fitness competition. With BIS technology, the physical therapist used the patient’s body composition to monitor fluid status and muscle mass in relation to the lymphedema. As the patient began more rigorous workouts, BIS was able to detect changes in fluid in the limb, allowing the patient and therapist to be more rigorous with her lymphedema management. The body composition data helped motivate the patient, as she couldn’t always see the changes that were happening in her muscles, but the BIS data kept her on track as her training routine intensified. The detailed data also helped the physical therapist play a role in driving the patient’s rehabilitation. Because the patient was losing weight and her body shape was changing, volume measurements were not as sensitive to understanding what was happening with the lymphedema symptoms. The personalized medicine that BIS data provided filled the gaps and the patient’s limb was in the best shape since her diagnosis. The patient successfully met her goal and qualified for a national competition. Both therapist and patient agreed that without BIS, this would have been difficult to achieve.
For physical therapists and other clinicians, BIS represents the future of tracking and managing lymphedema because it is simple to use, incorporates easily into the workflow and is scalable. BIS also eliminates the need for an examination room and can be administered by trained clinical staff allowing more time for physicians and therapists to better manage their patients.
Finally, BIS is an excellent tool for early detection to facilitate interventions that can be highly effective in preventing cancer—related lymphedema for at-risk survivors. BIS measures extracellular fluid, making early screening of lymphatic function possible so that subtle lymphatic changes can be addressed before they become permanent.
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