Relationship of Adjuvant Radiation and the Lymphedema Index

Abstract

Background Immediate lymphaticovenular bypass (immediate lymphatic reconstruction [ILR]) at the time of axillary lymph node dissection has emerged as a preventative paradigm to decrease the incidence of breast cancer–related lymphedema in high-risk patients. These patients are often treated with adjuvant therapies, including radiation. Bioimpedance spectroscopy is a validated tool for trending breast cancer–related lymphedema and identifying subclinical disease. Lymphedema Index (LDEX) values are commonly obtained in ILR patients; however, postoperative trends and relationships with adjuvant treatments are yet to be reported in the literature. Methods After International Review Board approval, 100 consecutive patients underwent axillary lymph node dissection with axillary reverse lymphatic mapping and ILR at a tertiary cancer center. These patients were then followed prospectively in a multidisciplinary lymphedema clinic at 3-month intervals with clinical examination, circumferential limb girth measurements and bioimpedance spectroscopy (LDEX). Results Seventy-two patients met inclusion for analysis at 3 months, 60 at 6 months, 51 at 9 months, 45 at 12 months, 41 at 15 months, and 22 at 18 months. A majority of the patients included underwent adjuvant radiation. Average LDEX score for patients who developed lymphedema was 3.02 at 3 months, at 29.1 months, 17.8 at 9 months, 15.05 at 12 months, 18.75 at 15 months, and 7.7 at 18 months. Patients who went on to develop lymphedema had a higher LDEX score at 6 months (29.1 vs 3.20, P = 0.1329), which reached a significant difference beginning at 9 months (17.8 vs 3.19, P = 0.0004). All patients who went on to develop lymphedema received adjuvant radiation. Conclusions These data provide valuable insight guiding follow-up after ILR. Six-month LDEX is much higher in patients who developed lymphedema, all of which underwent adjuvant radiation therapy, which correlates with the time of completion of their treatment. Average LDEX value after this remains significantly higher in this population. Patients who demonstrate this increase in LDEX and received adjuvant radiation are at highest risk to develop lymphedema despite ILR. All patients who developed lymphedema despite ILR had adjuvant radiation, and this is likely a contributing factor. Injury from adjuvant radiation and its impact after ILR is not insignificant and warrants further studies.

The Impact of Obesity on Success of Immediate Lymphatic Reconstruction for Prevention of Breast Cancer–Related Lymphedema

“…In our experience, patients who developed BCRL despite ILR were significantly more likely to be of an obese BMI at the time of surgery. The only additional significant difference between groups was the rate of adjuvant radiation therapy, a known risk factor for the development of lymphedema, which we have previously published upon 15 . However, further multivariate analysis demonstrated that there is a significant effect of BMI on the risk for BCRL independent of adjuvant radiation (OR 2.6 [1.2–5.5], P = 0.01).…”

“…The only additional significant difference between groups was the rate of adjuvant radiation therapy, a known risk factor for the development of lymphedema, which we have previously published upon. 15 However, further multivariate analysis demonstrated that there is a significant effect of BMI on the risk for BCRL independent of adjuvant radiation (OR 2.6 [1.2-5.5], P = 0.01). Given the baseline increased risk of developing BCRL with an obese BMI, our results may be further explained by additional genetic and cellular factors contributing to obesity and development of BCRL.…”

“…Development of BCRL was evaluated through subjective report of symptoms, clinical assessment, circumferential limb girth measurements (>5% larger relative to normal, contralateral limb), and BIS (SOZO Impedimed, Carlsbad, CA) with an LDEX equal to or greater than 10 units from preoperative baseline concerning for lymphedema. 2,6,15 Patients who presented for at least 1 follow-up visit in our multidisciplinary lymphedema clinic met the criteria for inclusion and were excluded if they had preoperative lymphedema, expired during the follow-up period, or if they were unable to maintain close follow-up.…”

“…Weight, height, and new symptoms were recorded, and circumferential limb girth measurements as well as Lymphedema Index scores using BIS were collected and recorded. Development of BCRL was evaluated through subjective report of symptoms, clinical assessment, circumferential limb girth measurements (>5% larger relative to normal, contralateral limb), and BIS (SOZO Impedimed, Carlsbad, CA) with an LDEX equal to or greater than 10 units from preoperative baseline concerning for lymphedema 2,6,15 …”