Abstract / Summary
Abstract The aim of this study was to assess the repeatability of upper limb volume measurements performed with the Kuhnke method using the Frustum Volume Calculation (FVC) in women with lymphedema after unilateral mastectomy. This cross-sectional methodological study included 101 women (stage I: n = 52; stage II: n = 49). Three independent physiotherapists, each with at least five years of clinical experience, performed two repeated measurements (T1, T2) of both the affected and the healthy limb using the Kuhnke FVC method. Repeatability was evaluated with intraclass correlation coefficients (ICC), standard error of measurement (SEM), and minimal detectable change (MDC). The mean volume of the healthy limb was ~ 2209–2210 ml, while the affected limb averaged ~ 2438–2440 ml, yielding a mean interlimb difference of 229–230 ml. Intra-rater reliability was excellent, with ICC values of 0.986 for the healthy limb, 0.983 for the affected limb, and 0.945 for the interlimb difference. SEM values ranged from 6 to 8 ml, and MDC values were 16–22 ml, indicating very low measurement error. Inter-rater analysis confirmed high agreement, with no statistically significant differences between raters (p≈0.99). The interlimb volume difference was more than twice as large in stage II lymphedema (314.7 ± 67.1 ml) compared with stage I (148.6 ± 38.7 ml; p < 0.000001). The Kuhnke method with FVC formula demonstrates excellent intra- and inter-rater repeatability and can be recommended as a simple, cost-effective, and clinically reliable tool for diagnosing and monitoring upper limb lymphedema in women after mastectomy.