OBJECTIVE:Lymphedema treatment is based on Decongestive Lymphedema Therapy (DLT) with an intensive phase followed by a long-term maintenance phase. This study aimed to observe volume variation over the intensive phase and 6 months later.METHODS:Prospective multicentre observational study of patients with unilateral lymphedema. The primary objective was to assess lymphedema volume variation between baseline, the end of intensive phase and 6 months later. Secondary objectives were to assess the frequency of heaviness limiting limb function and treatments safety predictors for volume reduction.RESULTS:Three hundred and six patients (89.9% women; 59.9±14.3 years old) with upper/lower (n=184/122) limb lymphedema were included. At the end of the intensive phase, median excess lymphedema volume reduction was 31.0% (41.7-19.9) followed by a 16.5% (5.9-42.3) median increase over the 6-month maintenance period phase. Previous intensive treatment was the only significant predictor of this response. As compared to baseline, heaviness limiting limb use was much less frequently reported at the end of the reductive phase (75.5% versus 42.3% respectively), and was more frequent at the end of the maintenance phase (62.6%). The most frequent adverse events reported were skin redness and compression marks (18.4 and 15.7% of patients, respectively). Blisters requiring treatment stoppage were rare (1.4%).CONCLUSIONS:Intensive phase decreases lymphedema volume and heaviness limiting limb function. The benefit is partially abolished after the first 6 months of maintenance. There is a need to consider how to provide optimal patient care for the long-term control of lymphedema.