For people undergoing treatment for head and neck cancer, severe mouth sores and pain can be debilitating, making it hard to eat, drink, and talk. A major review of 30 clinical trials, involving over 1,700 patients, looked at whether a non-invasive light therapy could help. This therapy, called photobiomodulation, uses specific wavelengths of light to stimulate healing.
The analysis found that compared to standard care, the light therapy significantly reduced the risk of developing severe oral mucositis (the painful mouth sores) and also significantly reduced the risk of experiencing severe oral pain. It also showed a significant improvement in salivary flow rate, which can help with dry mouth. However, the therapy did not show a significant effect on patients' reported feelings of dry mouth (xerostomia) or on their overall quality of life scores.
The researchers conclude that photobiomodulation appears promising for reducing these specific, painful side effects. However, they strongly caution that the certainty of this evidence is currently low, and many of the studies had flaws, so more high-quality research is needed before firm recommendations can be made.