SAN ANTONIO – Extracorporeal shock wave therapy shows early promise for limiting the often-vexing problem of lymphedema arising after axillary lymphadenectomy.
In the first 10 affected patients treated in an ongoing randomized, sham-controlled clinical trial, lymphedema, as measured by median whole-arm water displacement, dropped from 4,200 mL at baseline by 192.5 mL after 10 once-weekly extracorporeal shock wave (ECSW) sessions. Patients who received sham sessions had a 12.5-mL decline from baseline measures, Dr. Sara Imboden reported at the San Antonio Breast Cancer Symposium.
Quantitative CT measures indicated the mean total cross-sectional area of the most swollen part of the arm decreased by 3% in the ECSW group, compared with 1.4% in the control group, added Dr. Imboden of the University of Bern (Switzerland).
A mean of 22 axillary lymph nodes had been removed from the breast cancer patients in the study. The ECSW therapy was performed over the length of the edematous arm at an energy density of 0.25-0.69 mJ/mm2 once per week for 10 weeks. The control group followed the same treatment schedule, but the shock waves were contained inside the probe during their sessions.
None of the patients had to interrupt ECSW therapy due to complications.
The researchers plan to expand the randomized trial to include 30 patients, and to augment the results with patient reports of symptoms based on questionnaires assessing body image and with extended follow-up to evaluate functioning and recurrences.
The likely mechanism of benefit in patients with lymphedema involves ECSW-induced stimulation of angiogenesis and lymphatic vessel regeneration. These results have been demonstrated in animal studies.
No medications have been shown effective in treating lymphedema. Conventional therapy entails repeated manual lymph drainage and compression bandages.
Dr. Imboden reported having no financial conflicts of interest with regard to this university-funded study.