The structured light scanner is a reliable, valid, and clinically feasible 3D laser scanner to assess leg volume in patients with leg lymphedema.

Abstract

To investigate the reliability, concurrent validity, and clinical feasibility of a structured light scanner (SLS) for measuring leg volume in patients with lymphedema. Leg volume was measured using the SLS, circumference measurements, and optoelectronic volumetry. Intra-and inter-rater reliability were assessed using intraclass correlation coefficients (ICCs), standard error of measurement (SEM), and smallest real difference (SRD). Concurrent validity was determined by calculating correlation coefficients. Clinical feasibility was evaluated through timing of procedures and a purpose-designed questionnaire. This cross-sectional study was conducted at the Center for Lymphedema, University Hospital Leuven, involving 33 patients (66 legs) with predominantly secondary (70%) and stage 2a (73%) lymphedema (NCT07017166). All three methods showed excellent reliability. Circumference measurements had the highest intra-rater (ICC: 0.999) and inter-rater (ICC: 0.999) reliability, followed by optoelectronic volumetry (intra-rater ICC: 0.988; inter-rater ICC: 0.994) and the SLS (intra-rater ICC: 0.986; inter-rater ICC: 0.982). SLS showed a strong correlation with circumference measurements and with optoelectronic volumetry. The SLS was the most clinically feasible. The SLS demonstrates good reliability and concurrent validity for assessing leg volume and appears to have fewer practical limitations than conventional methods, although further research is needed to reduce measurement error and confirm clinical implementation.