A Prospective Study of L-Dex Values in Breast Cancer Patients Pretreatment and Through 12 Months Postoperatively.

BACKGROUND: Data regarding pretreatment, bioimpedance spectroscopy (BIS) L-Dex® values for patients newly diagnosed with breast cancer, and longitudinal data 12 months postoperatively are lacking. This study describes L-Dex values at the time of breast cancer diagnosis and maximum L-Dex change within 12 months of surgery. METHODS AND RESULTS: Patients were enrolled in a parent, clinical trial that compares the effectiveness of BIS for early detection of breast cancer-related lymphedema to tape measurement. A total of 280 women with a pretreatment and at least one postoperative L-Dex measurement (within 12 months of surgery) were included. Pretreatment L-Dex readings were compared with population norms and maximum L-Dex changes within 12 months were examined. An L-Dex U400 device was used to obtain BIS measurements. The documented normative mean value using this device is 0.00, which is at the 49th percentile for this sample. Approximately 6% of patients had a pretreatment L-Dex value of ≥7.0; 1.8% had an L-Dex value ≥10.0. For 12 months, 17.1% (n = 48) of patients had a maximum change in L-Dex value from pretreatment of ≥7.0 L-Dex units, suggestive of clinical lymphedema. CONCLUSIONS: At the time of breast cancer diagnosis, L-Dex values are similar to normative values. Identified maximum changes in L-Dex values 12 months postoperatively suggest that frequent L-Dex measurements during that time frame are of potential clinical benefit. Our findings are consistent with research supporting an L-Dex value of ≥7 as indicative of clinical lymphedema with subclinical lymphedema logically occurring at somewhat lower likely, near ≥6.5.

Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema.

BACKGROUND: Breast cancer treatment-related lymphedema (BCRL) arises from a mechanical insufficiency following cancer therapies. Early BCRL detection and personalized intervention require an improved understanding of the physiological processes that initiate lymphatic impairment. Here, internal magnetic resonance imaging (MRI) measures of the tissue microenvironment were paired with clinical measures of tissue structure to test fundamental hypotheses regarding structural tissue and muscle changes after the commonly used therapeutic intervention of manual lymphatic drainage (MLD). METHODS AND RESULTS: Measurements to identify lymphatic dysfunction in healthy volunteers (n = 29) and patients with BCRL (n = 16) consisted of (1) limb volume, tissue dielectric constant, and bioelectrical impedance (i.e., non-MRI measures); (2) qualitative 3 Tesla diffusion-weighted, T1-weighted and T2-weighted MRI; and (3) quantitative multi-echo T2 MRI of the axilla. Measurements were repeated in patients immediately following MLD. Normative control and BCRL T2 values were quantified and a signed Wilcoxon Rank-Sum test was applied (significance: two-sided p < 0.05). Non-MRI measures yielded significant capacity for discriminating between arms with versus without clinical signs of BCRL, yet yielded no change in response to MLD. Alternatively, a significant increase in deep tissue T2 on the involved (pre T2 = 0.0371 ± 0.003 seconds; post T2 = 0.0389 ± 0.003; p = 0.029) and contralateral (pre T2 = 0.0365 ± 0.002; post T2 = 0.0395 ± 0.002; p < 0.01) arms was observed. Trends for larger T2 increases on the involved side after MLD in patients with stage 2 BCRL relative to earlier stages 0 and 1 BCRL were observed, consistent with tissue composition changes in later stages of BCRL manifesting as breakdown of fibrotic tissue after MLD in the involved arm. Contrast consistent with relocation of fluid to the contralateral quadrant was observed in all stages. CONCLUSION: Quantitative deep tissue T2 MRI values yielded significant changes following MLD treatment, whereas non-MRI measurements did not vary. These findings highlight that internal imaging measures of tissue composition may be useful for evaluating how current and emerging therapies impact tissue function.