How do the L-Dex compare to volume measurements (tape measure)?
L-Dex measurements are a more sensitive and direct measure of swelling in the extracellular compartment. Volume measurements can be affected by weight gain (such as fat deposition) or muscle loss (often associated with inactivity after surgery). This causes inconsistencies when trying to discern the volume changes due to lymphedema from those that are not. For this reason, “exact” comparisons between L-Dex values and volume measurements cannot be made. Statements such as “an L-Dex value of 20 is equivalent to volume of 100ml” are not verifiable because there is no practical way to ensure that the volume change measured has not been confounded by weight gain or loss (muscle or fat) in the arm.
