Upper limbs volumetry by the disc method: methodology and results evaluation for breast cancer related lymphedema

The study focuses on upper limb volumetry using the disc method, analyzing 176 patients with secondary lymphedema post breast cancer treatment. Technique reproducibility was assessed by comparing volumes of 184 non-edematous limbs in short-term dynamics. A difference of less than 8% relative to a smaller limb volume is considered unreliable, with thresholds for upper arm and hand at 12 % and forearm at 10%. Correlation analysis involved 11 anthropometric indicators and 13 indices. The circle at the elbow joint showed the strongest relationship with volume $(\mathrm{r}= 0.87)$ ; the volume indexed to it was $103.71 \pm 12.22 \text{ml} / \text{cm}$ The patient's weight was in second place in terms of the severity of the correlation $(\mathbf{r}=0.84)$ , the indexed indicator was $36.17\pm 4.19$ ml/kg. Of the body circumferences, the best indicator is the chest circumference (r 0.71), the index of which is $31.57\pm 5.02\textbf{ml}/\textbf{cm}$ The linear regression coefficients were also calculated: intercept (a), slope (b) and standard error of estimate of a linear regression equation (S). For the circumference of the elbow joint they were (a, b, S): -3292.457, 224.327, 243.766. For weight: - 154.0319, 38.141, 348.58. For chest circumference: -1317.363, 45.9891, 453.83. The article presents the described indicators for other anthropometric indicators with a high degree of correlation with the volume of the upper limb. Values calculated taking into account the length of the limb are also given. To assess the severity of edema, it is proposed to use the Z-Score, calculated from the results of regression analysis.