Calculating arm volume
Breast cancer-related lymphoedema is usually diagnosed as as a volume difference of at least 200 ml between arms.
How do you determine arm volume? Researchers from Brazil created this free tool for you to use. You can measure your patients arms at 7cm intervals with a tape measure, starting from the ulnar styloid, then enter the circumferential measures via the online calculator. A screen display of the online calculator is below.
Reference: Bevilacqua JL, Kattan MW, Changhong Y, Koifman S, Mattos IE, Koifman RJ, Bergmann A. Nomograms for predicting the risk of arm lymphedema after axillary dissection in breast cancer. Annals of surgical oncology. 2012 Aug;19(8):2580-9.