Large-area Low-level Laser Therapy for Breast Cancer-related Lymphedema: a Randomized, Placebo-controlled Study

Breast cancer-related lymphedema (BCRL) is common complication after cancer treatment. The incidence of BCRL around is 16.6% (95% CI 13·6-20·2) after the diagnosis and higher among the group receiving the sentinel biopsy or axillary lymph dissection. The lymphedema arises from the accumulation of protein-rich lymph fluid in the interstitial spaces then results in chronic inflammation with symptoms of fibrosis, pain, limited range of motion or paresthesia. The BRCL is chronic and progressive condition, and the severity also changes over time. The definition and cut points of BCRL using inter-limb volume or arm circumference varied across the studies by different measure method. Currently, the International Society of Lymphology suggests calculating arm volume from circumferences through the truncated cone formula to qualify the severity. On the other hand, previous research found the skin and subcutis were thickened in the ipsilateral arm of patients with BCRL. Thus, the measurement of skin thickness using ultrasound may also practical to detect the progression of lymphedema. Except for physical change of upper limb, the symptoms of BCRL are also concerned. One of the most common morbidity is pain, mostly presenting 1 month after surgery (56.6%). Furthermore, BCRL might decrease shoulder range of motion. Previous study demonstrated that shoulder mobility was usually restricted at 1 month postoperatively and abduction and forward flexion were limited at first. Thus, functional disability may occurred and life of quality may be influenced. To evaluate the ability to perform functional activities, the Disability of Arm, Shoulder, and Hand Questionnaire (DASH) is an useful tool to assess the patients with BCRL.

Currently, although complete decongestive therapy (CDT) has been the standard therapy, there is still various type of noninvasive treatment on BCRL, for example, low-level laser therapy (LLLT). Low-level laser therapy (LLLT), also named photobiomodulation therapy (PBMT), is a conservative therapy through utilizing wave lengths of red or near infrared light between 650 and 1000 nm to stimulate wound healing and reduce inflammation, edema, and pain. Moreover, the Food and Drug Administration (FDA) approved the use of the LLLT for treatment of postmastectomy lymphedema in November 2006. Previous studies have demonstrated the effect of LLLT on BCRL with comparison to physical therapy or placebo. However, there is still limited data about the LLLT with different light area on improvement of severity and symptoms of BCRL. Therefore, this study is conducted to compare between efficacy of large and small area of low-level laser therapy (LLLT) in treatment of post mastectomy lymphedema.