Carati, C.J., Anderson, S.N., Gannon, B.J., & Piller, N.B. (2003). Treatment of post-mastectomy lymphedema with low-level laser therapy. Cancer, 98(6), 1114–1122.

To study postmastectomy lymphedema using low-level laser therapy (LLLT).

The control group received a placebo with one block of sham therapy followed by an eight-week period of rest and then one week of LLLT. The study group received two blocks of LLLT separated by an eight-week period of rest.

• The study sample (N = 61) was comprised of female patients who were randomized to the control group (n = 28) and the study group (n = 33). 
• Patients were included in the study if they were aged 18 years or older, female, and had clinically manifested postmastectomy. 
• Patients were excluded from the study if they had current metastases, a history of severe trauma to the arm, instability of condition, or cellulitis within past three months.
• Lymphedema was defined as a greater than 200 ml difference between arms. 

The study took place in Australia.

The study used a double-blind, randomized, placebo-controlled trial design, with 30 weeks of follow-up measurements.

• Objective measurements were taken at the beginning and end of every session.
• Perometry measured limb circumference.
• Bioimpedence provided an objective measure of fluid distribution.
• Tonometry provided indication of the compliance of the skin.
• Data were analyzed using analysis of variance and multiple regressions; p < 0.05 was determined using t-tests.

There was no significant effect of placebo treatment or just one cycle of LLLT treatment on mean affected limb volume. There was no significant decrease in limb volume immediately after two treatments of LLLT. Limb volume at three months after two LLLT treatments were significantly less than after placebo treatment (p < 0.017). Limb extracellular fluid (ECF) was significantly decreased in placebo and with one treatment of LLLT; however, the mean ECF was most reduced after two LLLT cycles. Significant decreases in tonometry readings (indicating increased tissue hardness) were noted in patients treated with placebo or one LLLT. Participants receiving two LLLT cycles had an increased tonometry reading, which indicates softening of the tissues. There was no significant effect on range of motion.

Two cycles of LLLT improved the condition of the lymphedema-affected limbs.

• The study sample was small.
• Special training is required.
• Use of laser makes costs higher.