Agreement Between Optoelectronic Volumetry and Circumferential Girth Measurements to Diagnose Lymphedema in Patients Submitted to Axillary Radical Lymphadenectomy for Treatment of Cutaneous Melanoma.

Background: To assess the agreement between indirect and optoelectronic volumetries to diagnose lymphedema based on arm volume difference in patients with axillary lymph node dissection (ALND) for cutaneous melanoma. Methods and Results: Patients were assessed by circumferential girth measurements (truncated cone formula) to determine the upper limb volumes (indirect volumetry) and by optoelectronic volumetry (Perometer®) of affected and control limbs. A diagnosis of lymphedema on each measuring method was defined as an absolute volume difference >200 mL or a relative volume >10%. Forty-six patients with ALND were included. There were no significant differences between the volume means or the mean absolute or relative differences measured by each method. Good correlation was observed between the volume of upper limbs for both the left (r = 0.998) and right (r = 0.985) arms. As for the diagnosis of lymphedema, an absolute volume difference >200 mL determined a prevalence of 28% (13/46) of lymphedema by indirect volumetry and 35% (16/46) by optoelectronics volumetry. The crude diagnostic agreement was 93% with a kappa = 85% (agreement adjusted by chance) between methods. If a 10% increase in the relative volume difference between the arms was used as the diagnostic criterion, prevalence was 20% (9/46) and 22% (10/46), respectively. Conclusion: There is good agreement between perometry and circumferential girth measurements when classifying patients as having a difference between arm volumes >200 mL or 10%, the most frequently used cutoffs to diagnose lymphedema.