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Study Overview
Objective. To evaluate the reliability, sensitivity, and specificity of bioelectrical impedance analysis (BIA) in the diagnosis of secondary lymphedema.
Design. Cross-sectional study utilizing test-retest method
Setting and participants. The researchers used a purposeful sampling technique to recruit women between 2010 and 2011 from a metropolitan cancer center and communities in the New York City metropolitan area. Participants included women who were 18 years of age or older and able to read and write in English. Exclusion criteria included patients with bilateral breast disease, recurrent cancer, artificial limb, knee, or hip, and kidney or heart failure. Study participants were divided into 3 groups: breast cancer survivors with lymphedema, those at risk for lymphedema, and healthy adult women (no history of breast cancer or lymphedema). Women in the at risk category had to have completed surgical treatment, chemotherapy and/or radiation within the 5 years prior to the study enrollment.
Measurements. Patient’s arms were measured by the same 2 researchers using sequential circumferential measurements. BIA was measured in all patients with the ImpXCA (Impedimed Inc, Pittsford, NY), an FDA-approved device that measures impedance and resistance of the extracellular fluid. The ImpXCA utilizes a scale to correlate BIA to an L-Dex (lymphedema index) ratio; –10 to +10 defines the normal range of L-Dex values for a patient without lymphedema. Measurements were taken at 5-minute increments for a total of 3 times at the same visit to test for stability of BIA.
Main results. 250 patients were in the sample: 42 with known lymphedema, 148 at risk for lymphedema, and 60 healthy female adults. L-Dex ratios ranged from –9.7 to 7.7 in the healthy population, –9.6 to 36.9 in the at risk group, and 0.9 to 115 in the group with lymphedema. Mean L-Dex ratios were significantly different between the healthy and lymphedema groups (P < 0.001) and the at risk and lymphedema groups (P < 0.001). There was no difference between the at risk and healthy groups (P = 0.85). Utilizing an L-Dex ratio cutoff of 7.1 provided 80% sensitivity and 90% specificity in the diagnosis of secondary lymphedema.
Reliability and reproducibility of BIA by ImpXCA using the L-Dex ratio was assessed using a test-retest method. Intra-class correlation coefficients (ICC) provided strong stability for the repeated measurements in the healthy group, with ICC = 0.99 (95% CI, 0.99–0.99), and in the at risk group, with ICC = 0.99 (95% CI, 0.99–0.99). There was also fair agreement in the repeated measurements in the lymphedema group, with ICC = 0.69 (95% CI, 0.58-0.82). All of these findings were statistically significant (P < 0.001).
Conclusion. The L-Dex ratio is reliable and reproducible and may be helpful in distinguishing women with lymphedema from those without lymphedema. BIA in conjunction with other tools, such as self-report of symptoms, circumferential measurements, and clinical observation, may have a role in diagnosing lymphedema.
Commentary
The first year and a half following surgical treatment for breast cancer is when providers tend to diagnose the initial onset of lymphedema [1]. Many women, however, go undiagnosed until the illness has progressed. Earlier treatment has the potential to improve patient outcomes [2]. Although awareness of secondary lymphedema among breast cancer survivors has increased over the past 10 years, the diagnosis remains difficult and the development of effective diagnostic tools continues to challenge health care providers.
The current gold standard for diagnosis is the water displacement method where the affected and unaffected extremities are each placed into a tank of water, and the displaced water is measured [3]. Greater than a 200 mL discrepancy between arms is used to make a diagnosis of lymphedema. While useful, this measurement is messy and difficult to set up, and thus underutilized. Many providers have turned to circumferential measurements as their primary method to diagnose and monitor lymphedema [4]. However, this method may miss patients in the earlier stages of lymphedema, since it measures the size of limbs rather than changes in the tissue. Without a definitive test to diagnose lymphedema, researchers and health care providers continue to search for the most accurate, reliable, and feasible means to assist in the diagnosis.
This cross-sectional study suggests that L-Dex can be helpful in detecting lymphedema. A weakness of the study is that the investigators did not compare the results of BIA to the current gold standard of water displacement, but rather to circumferential measurement. In addition, while all results were reproducible, the difference between groups was notable in terms of age and body mass index, making it difficult to generalize to all patients at risk for lymphedema or differentiate results by those same variables. Although having the same 2 investigators obtain circumferential tape measurements is preferable to having multiple investigators do so, such measurements are still at risk for human error.
BIA shows promise as a diagnostic tool. Future studies should include healthy patients with characteristics similar to those of at risk patients and lymphedema patients. Efforts also could be directed towards determining whether combining BIA with other methods, such as self-report, circumferential measurements, and close observation, may offer greater sensitivity and specificity than one method alone.
Applications for Clinical Practice
Secondary lymphedema is a common complication caused by surgical treatment of breast cancer. Early treatment is linked to a decrease in debilitating factors such as immobility of affected joints, skin changes, and risk for infection. Measurement of extracellular fluid utilizing L-Dex ratios produces reliable and repeatable results in the assessment for lymphedema. Paired with additional tools and resources it may be helpful in making a diagnosis, which is normally difficult in its earliest stages. The early diagnosis of secondary lymphedema may allow for improved quality of life for survivors of breast cancer.
—Jennifer L. Nahum, MSN, CPNP-AC, PPCNP-BC, and Allison Squires, PhD, RN
1. Czerniec SA, Ward LC, Lee MJ, et al. Segmental measurement of breast cancer-related arm lymphoedema using perometry and bioimpedance spectroscopy. Support Care Cancer. 2011;19:703–10.
2. Damstra RJ, Voesten HG, van Schelven WD, van der Lei B. Lymphatic venous anastomosis (LVA) for treatment of secondary arm lymphedema. A prospective study of 11 LVA procedures in 10 patients with breast cancer related lymphedema and a critical review of the literature. Breast Cancer Res Treat 2009;113:199–206.
3. Brorson H, Höijer P. Standardised measurements used to order compression garments can be used to calculate arm volumes to evaluate lymphoedema treatment. Plast Surg Hand Surg 2012;46:410–5.
4. Langbecker D, Hayes SC, Newman B, Janda M. Treatment for upper-limb and lower-limb lymphedema by professionals specializing in lymphedema care. Eur J Cancer Care (Engl). 2008;17:557–64.
Study Overview
Objective. To evaluate the reliability, sensitivity, and specificity of bioelectrical impedance analysis (BIA) in the diagnosis of secondary lymphedema.
Design. Cross-sectional study utilizing test-retest method
Setting and participants. The researchers used a purposeful sampling technique to recruit women between 2010 and 2011 from a metropolitan cancer center and communities in the New York City metropolitan area. Participants included women who were 18 years of age or older and able to read and write in English. Exclusion criteria included patients with bilateral breast disease, recurrent cancer, artificial limb, knee, or hip, and kidney or heart failure. Study participants were divided into 3 groups: breast cancer survivors with lymphedema, those at risk for lymphedema, and healthy adult women (no history of breast cancer or lymphedema). Women in the at risk category had to have completed surgical treatment, chemotherapy and/or radiation within the 5 years prior to the study enrollment.
Measurements. Patient’s arms were measured by the same 2 researchers using sequential circumferential measurements. BIA was measured in all patients with the ImpXCA (Impedimed Inc, Pittsford, NY), an FDA-approved device that measures impedance and resistance of the extracellular fluid. The ImpXCA utilizes a scale to correlate BIA to an L-Dex (lymphedema index) ratio; –10 to +10 defines the normal range of L-Dex values for a patient without lymphedema. Measurements were taken at 5-minute increments for a total of 3 times at the same visit to test for stability of BIA.
Main results. 250 patients were in the sample: 42 with known lymphedema, 148 at risk for lymphedema, and 60 healthy female adults. L-Dex ratios ranged from –9.7 to 7.7 in the healthy population, –9.6 to 36.9 in the at risk group, and 0.9 to 115 in the group with lymphedema. Mean L-Dex ratios were significantly different between the healthy and lymphedema groups (P < 0.001) and the at risk and lymphedema groups (P < 0.001). There was no difference between the at risk and healthy groups (P = 0.85). Utilizing an L-Dex ratio cutoff of 7.1 provided 80% sensitivity and 90% specificity in the diagnosis of secondary lymphedema.
Reliability and reproducibility of BIA by ImpXCA using the L-Dex ratio was assessed using a test-retest method. Intra-class correlation coefficients (ICC) provided strong stability for the repeated measurements in the healthy group, with ICC = 0.99 (95% CI, 0.99–0.99), and in the at risk group, with ICC = 0.99 (95% CI, 0.99–0.99). There was also fair agreement in the repeated measurements in the lymphedema group, with ICC = 0.69 (95% CI, 0.58-0.82). All of these findings were statistically significant (P < 0.001).
Conclusion. The L-Dex ratio is reliable and reproducible and may be helpful in distinguishing women with lymphedema from those without lymphedema. BIA in conjunction with other tools, such as self-report of symptoms, circumferential measurements, and clinical observation, may have a role in diagnosing lymphedema.
Commentary
The first year and a half following surgical treatment for breast cancer is when providers tend to diagnose the initial onset of lymphedema [1]. Many women, however, go undiagnosed until the illness has progressed. Earlier treatment has the potential to improve patient outcomes [2]. Although awareness of secondary lymphedema among breast cancer survivors has increased over the past 10 years, the diagnosis remains difficult and the development of effective diagnostic tools continues to challenge health care providers.
The current gold standard for diagnosis is the water displacement method where the affected and unaffected extremities are each placed into a tank of water, and the displaced water is measured [3]. Greater than a 200 mL discrepancy between arms is used to make a diagnosis of lymphedema. While useful, this measurement is messy and difficult to set up, and thus underutilized. Many providers have turned to circumferential measurements as their primary method to diagnose and monitor lymphedema [4]. However, this method may miss patients in the earlier stages of lymphedema, since it measures the size of limbs rather than changes in the tissue. Without a definitive test to diagnose lymphedema, researchers and health care providers continue to search for the most accurate, reliable, and feasible means to assist in the diagnosis.
This cross-sectional study suggests that L-Dex can be helpful in detecting lymphedema. A weakness of the study is that the investigators did not compare the results of BIA to the current gold standard of water displacement, but rather to circumferential measurement. In addition, while all results were reproducible, the difference between groups was notable in terms of age and body mass index, making it difficult to generalize to all patients at risk for lymphedema or differentiate results by those same variables. Although having the same 2 investigators obtain circumferential tape measurements is preferable to having multiple investigators do so, such measurements are still at risk for human error.
BIA shows promise as a diagnostic tool. Future studies should include healthy patients with characteristics similar to those of at risk patients and lymphedema patients. Efforts also could be directed towards determining whether combining BIA with other methods, such as self-report, circumferential measurements, and close observation, may offer greater sensitivity and specificity than one method alone.
Applications for Clinical Practice
Secondary lymphedema is a common complication caused by surgical treatment of breast cancer. Early treatment is linked to a decrease in debilitating factors such as immobility of affected joints, skin changes, and risk for infection. Measurement of extracellular fluid utilizing L-Dex ratios produces reliable and repeatable results in the assessment for lymphedema. Paired with additional tools and resources it may be helpful in making a diagnosis, which is normally difficult in its earliest stages. The early diagnosis of secondary lymphedema may allow for improved quality of life for survivors of breast cancer.
—Jennifer L. Nahum, MSN, CPNP-AC, PPCNP-BC, and Allison Squires, PhD, RN
Study Overview
Objective. To evaluate the reliability, sensitivity, and specificity of bioelectrical impedance analysis (BIA) in the diagnosis of secondary lymphedema.
Design. Cross-sectional study utilizing test-retest method
Setting and participants. The researchers used a purposeful sampling technique to recruit women between 2010 and 2011 from a metropolitan cancer center and communities in the New York City metropolitan area. Participants included women who were 18 years of age or older and able to read and write in English. Exclusion criteria included patients with bilateral breast disease, recurrent cancer, artificial limb, knee, or hip, and kidney or heart failure. Study participants were divided into 3 groups: breast cancer survivors with lymphedema, those at risk for lymphedema, and healthy adult women (no history of breast cancer or lymphedema). Women in the at risk category had to have completed surgical treatment, chemotherapy and/or radiation within the 5 years prior to the study enrollment.
Measurements. Patient’s arms were measured by the same 2 researchers using sequential circumferential measurements. BIA was measured in all patients with the ImpXCA (Impedimed Inc, Pittsford, NY), an FDA-approved device that measures impedance and resistance of the extracellular fluid. The ImpXCA utilizes a scale to correlate BIA to an L-Dex (lymphedema index) ratio; –10 to +10 defines the normal range of L-Dex values for a patient without lymphedema. Measurements were taken at 5-minute increments for a total of 3 times at the same visit to test for stability of BIA.
Main results. 250 patients were in the sample: 42 with known lymphedema, 148 at risk for lymphedema, and 60 healthy female adults. L-Dex ratios ranged from –9.7 to 7.7 in the healthy population, –9.6 to 36.9 in the at risk group, and 0.9 to 115 in the group with lymphedema. Mean L-Dex ratios were significantly different between the healthy and lymphedema groups (P < 0.001) and the at risk and lymphedema groups (P < 0.001). There was no difference between the at risk and healthy groups (P = 0.85). Utilizing an L-Dex ratio cutoff of 7.1 provided 80% sensitivity and 90% specificity in the diagnosis of secondary lymphedema.
Reliability and reproducibility of BIA by ImpXCA using the L-Dex ratio was assessed using a test-retest method. Intra-class correlation coefficients (ICC) provided strong stability for the repeated measurements in the healthy group, with ICC = 0.99 (95% CI, 0.99–0.99), and in the at risk group, with ICC = 0.99 (95% CI, 0.99–0.99). There was also fair agreement in the repeated measurements in the lymphedema group, with ICC = 0.69 (95% CI, 0.58-0.82). All of these findings were statistically significant (P < 0.001).
Conclusion. The L-Dex ratio is reliable and reproducible and may be helpful in distinguishing women with lymphedema from those without lymphedema. BIA in conjunction with other tools, such as self-report of symptoms, circumferential measurements, and clinical observation, may have a role in diagnosing lymphedema.
Commentary
The first year and a half following surgical treatment for breast cancer is when providers tend to diagnose the initial onset of lymphedema [1]. Many women, however, go undiagnosed until the illness has progressed. Earlier treatment has the potential to improve patient outcomes [2]. Although awareness of secondary lymphedema among breast cancer survivors has increased over the past 10 years, the diagnosis remains difficult and the development of effective diagnostic tools continues to challenge health care providers.
The current gold standard for diagnosis is the water displacement method where the affected and unaffected extremities are each placed into a tank of water, and the displaced water is measured [3]. Greater than a 200 mL discrepancy between arms is used to make a diagnosis of lymphedema. While useful, this measurement is messy and difficult to set up, and thus underutilized. Many providers have turned to circumferential measurements as their primary method to diagnose and monitor lymphedema [4]. However, this method may miss patients in the earlier stages of lymphedema, since it measures the size of limbs rather than changes in the tissue. Without a definitive test to diagnose lymphedema, researchers and health care providers continue to search for the most accurate, reliable, and feasible means to assist in the diagnosis.
This cross-sectional study suggests that L-Dex can be helpful in detecting lymphedema. A weakness of the study is that the investigators did not compare the results of BIA to the current gold standard of water displacement, but rather to circumferential measurement. In addition, while all results were reproducible, the difference between groups was notable in terms of age and body mass index, making it difficult to generalize to all patients at risk for lymphedema or differentiate results by those same variables. Although having the same 2 investigators obtain circumferential tape measurements is preferable to having multiple investigators do so, such measurements are still at risk for human error.
BIA shows promise as a diagnostic tool. Future studies should include healthy patients with characteristics similar to those of at risk patients and lymphedema patients. Efforts also could be directed towards determining whether combining BIA with other methods, such as self-report, circumferential measurements, and close observation, may offer greater sensitivity and specificity than one method alone.
Applications for Clinical Practice
Secondary lymphedema is a common complication caused by surgical treatment of breast cancer. Early treatment is linked to a decrease in debilitating factors such as immobility of affected joints, skin changes, and risk for infection. Measurement of extracellular fluid utilizing L-Dex ratios produces reliable and repeatable results in the assessment for lymphedema. Paired with additional tools and resources it may be helpful in making a diagnosis, which is normally difficult in its earliest stages. The early diagnosis of secondary lymphedema may allow for improved quality of life for survivors of breast cancer.
—Jennifer L. Nahum, MSN, CPNP-AC, PPCNP-BC, and Allison Squires, PhD, RN
1. Czerniec SA, Ward LC, Lee MJ, et al. Segmental measurement of breast cancer-related arm lymphoedema using perometry and bioimpedance spectroscopy. Support Care Cancer. 2011;19:703–10.
2. Damstra RJ, Voesten HG, van Schelven WD, van der Lei B. Lymphatic venous anastomosis (LVA) for treatment of secondary arm lymphedema. A prospective study of 11 LVA procedures in 10 patients with breast cancer related lymphedema and a critical review of the literature. Breast Cancer Res Treat 2009;113:199–206.
3. Brorson H, Höijer P. Standardised measurements used to order compression garments can be used to calculate arm volumes to evaluate lymphoedema treatment. Plast Surg Hand Surg 2012;46:410–5.
4. Langbecker D, Hayes SC, Newman B, Janda M. Treatment for upper-limb and lower-limb lymphedema by professionals specializing in lymphedema care. Eur J Cancer Care (Engl). 2008;17:557–64.
1. Czerniec SA, Ward LC, Lee MJ, et al. Segmental measurement of breast cancer-related arm lymphoedema using perometry and bioimpedance spectroscopy. Support Care Cancer. 2011;19:703–10.
2. Damstra RJ, Voesten HG, van Schelven WD, van der Lei B. Lymphatic venous anastomosis (LVA) for treatment of secondary arm lymphedema. A prospective study of 11 LVA procedures in 10 patients with breast cancer related lymphedema and a critical review of the literature. Breast Cancer Res Treat 2009;113:199–206.
3. Brorson H, Höijer P. Standardised measurements used to order compression garments can be used to calculate arm volumes to evaluate lymphoedema treatment. Plast Surg Hand Surg 2012;46:410–5.
4. Langbecker D, Hayes SC, Newman B, Janda M. Treatment for upper-limb and lower-limb lymphedema by professionals specializing in lymphedema care. Eur J Cancer Care (Engl). 2008;17:557–64.