Modern series have revealed that rates of lymphedema are quite low after de-escalated modern treatments for breast cancer. Here is an interesting, if somewhat complicated, normal tissue complication probability model for lymphedema following breast radiation. Per usual, the two biggest culprits were the number of nodes dissected and the volume of axilla—specifically the ALTJ—receiving at least 35 Gy. An online tool is needed to plug and play numbers to best individualize risk, but in general there were three risk groups based on two risk factors: >10 dissected nodes and ALTJ V35 ≥40%. Rate of lymphedema for the high-risk group (both factors present) was 19%, for the moderate-risk group (one risk factor) was 6%, and for the low-risk group (neither risk factor) was a paltry 0.5%.
Park, Int J Radiat Oncol Biol Phys 2023