Layer-Specific Assessment of Dermal Thickness and Stiffness Using Shear Wave Elastography in Gynecologic Cancer-Related Lower-Limb Lymphedema: An Exploratory Cross-Sectional Study

Objective: To characterize layer-specific changes in superficial tissues using shear wave elastography (SWE) in women with gynecologic cancer-related lower-limb lymphedema, including clinically asymptomatic contralateral limbs and affected limbs with different clinical severity levels. Methods: This exploratory observational cross-sectional study employed a mixed retrospective–prospective design. Forty women with gynecologic cancer-related lower-limb lymphedema and 20 healthy controls underwent grayscale ultrasound and SWE examinations. Dermal and subcutaneous thickness and stiffness were measured at three standardized medial sites: the upper calf, mid-calf, and medial ankle. For unilateral lymphedema, SWE-derived tissue parameters of clinically asymptomatic contralateral limbs were compared with those of healthy controls after adjustment for age and body mass index (BMI). To evaluate differences across clinical severity groups, affected limbs were categorized into mild and severe lymphedema groups, and overall differences among healthy controls, mild lymphedema, and severe lymphedema groups were assessed using the Kruskal–Wallis omnibus test, followed by Dunn’s post hoc analysis for pairwise comparisons. Spearman correlation analysis was performed to assess associations between clinical characteristics and SWE-derived parameters. Interobserver reproducibility was evaluated using intraclass correlation coefficients. Results: Clinically asymptomatic contralateral limbs demonstrated higher dermal thickness and stiffness values compared with healthy controls, whereas subcutaneous alterations were less consistent. Across healthy controls, mild lymphedema, and severe lymphedema groups, omnibus analysis revealed significant differences in dermal thickness, dermal stiffness, and subcutaneous thickness, while subcutaneous stiffness showed no significant differences. Both mild and severe lymphedema groups exhibited greater dermal thickness, dermal stiffness, and subcutaneous thickness than healthy controls at all assessed sites; however, differences between mild and severe lymphedema groups were limited. Lymphedema severity stage, disease duration, and BMI were positively associated with multiple SWE-derived parameters. SWE measurements demonstrated excellent interobserver reproducibility. Conclusion: SWE demonstrated layer-specific differences in dermal thickness and stiffness across clinically defined groups of gynecologic cancer-related lower-limb lymphedema. Clinically asymptomatic contralateral limbs showed measurable dermal differences compared with healthy controls; however, the clinical significance of these findings requires further evaluation in prospective longitudinal studies. Keywords: lymphedema, shear wave elastography, ultrasonography, dermal stiffness, gynecologic cancer