Effect of various photobiomodulation regimens on breast cancer-related lymphedema: A systematic review and meta-analysis

Breast cancer-related lymphedema (BCRL) is common among patients who have completed their cancer treatment. Although low-level laser therapy (LLLT) has been explored as a treatment option for BCRL, we could not find a regimen that is more effective than others. This meta-analysis aimed to organize existing research and determine the optimal combination of LLLT parameters for BCRL treatment. Studies were collected from four online databases: Embase, Ovid Medline, Cochrane, and Cinahl. The collected studies were reviewed by two of the authors. We focused on the aspects of the treatment area, treatment regimen, and total treatment sessions across the included studies. The comparisons between LLLT and non-LLLT were performed through a meta-analysis. Post-treatment QOL was significantly better in the axillary group. The group treated "three times/week with a laser density of 1.5–2 J/cm²" had significantly better outcomes in terms of swelling reduction, both immediately post-treatment and at 1–3 months follow-ups. The group with > 15 treatment sessions had significantly better post-treatment outcomes regarding reduced swelling and improved grip strength. According to these results, LLLT can relieve the symptoms of BCRL by reducing limb swelling and improving QOL. Further exploration found that a treatment approach targeting the axilla, combined with an increased treatment frequency, appropriate laser density, and extended treatment course, yielded better outcomes. However, further rigorous, large-scale studies, including long-term follow-up, are needed to substantiate this regimen.