Lau, R.W., & Cheing, G.L. (2009). Managing postmastectomy lymphedema with low-level laser therapy. Photomedicine and Laser Surgery, 27(5), 763–769.

To investigate effects of low-level laser therapy in managing lymphedema

Women were randomly assigned to laser treatment or usual care. Subjects in the laser group received low-level laser therapy (LLLT) three times a week for four weeks to the axillary region. Outcome measures were assessed at baseline, after four weeks of treatment and again at a four-week follow-up.

• The study sample (N = 21) was comprised of female patients. 
• Mean age range was 50.9–51.3 years.
• Patients had undergone unilateral mastectomy for breast cancer and clinically manifested lymphedema of the arm. 
• Patients were not receiving any concurrent cancer treatment.

The study took place in an outpatient setting in China.

The study used a single-blind, randomized controlled trial design.

• Arm volume was measured using a tank volumeter.
• Tissue pressure resistance was measured using a tonometer.
• Patients took the Disability of Arm Shoulder and Hand (DASH) questionnaire.

In the laser group, arm volume decreased significantly (p = 0.000), whereas those in the control group had a significant increase at the four-week follow-up. Group differences were significant (p = 0.044) at the four-week follow-up time point. For the first month, there were no significant differences between groups. Over time, the laser group showed a significant increase in tonomety readings at some sites (p = 0.000), indicating less tissue hardness, while there were no changes in the control group. Mean DASH scorers decreased significantly from baseline in the laser group (p = 0.04). There were no significant changes in DASH scores in the control group.

Low-level laser treatment in the study appeared to improve subjective pain and disability, improve tissue tone, and reduce lymphedema.

• The study sample was small, with less than 30 participants.
• Although authors state the study was single blinded, patients would have known if they were or were not receiving laser treatment because no sham control was used.
• No information was obtained or reported about other patient activities and behaviors that are known to potentially affect lymphedema development

Low-level laser therapy is promising for management of lymphedema postmastectomy.