Photobiomodulation reduces severe oral mucositis (RR 0.46) and pain (RR 0.35) in head and neck cancer patients

PURPOSE: To systematically review and analyze the effects of photobiomodulation on oral mucositis, xerostomia, salivary flow rates, oral pain, and quality of life in patients with head and neck cancer. METHODS: A systematic search of six databases was conducted up to April 2025. Eligible randomized controlled trials (RCTs) examined the effects of photobiomodulation on the specified outcomes in patients with head and neck cancer. Pooled estimates (risk ratio [RR] and standardized mean difference [SMD]) were calculated using a three-level mixed-effects meta-analysis. RESULTS: Thirty-three articles describing 30 RCTs (n = 1748) were included. Photobiomodulation significantly reduced the risk of severe oral mucositis (RR 0.46, 95% CI: 0.29-0.71, P < 0.001) and severe oral pain (RR 0.35, 95% CI: 0.23-0.53, P < 0.001) compared with controls. Significant improvements were also observed for salivary flow rate (SMD 0.75, 95% CI: 0.03-1.46, P = 0.044). No significant effects were observed on xerostomia (SMD -0.07, 95% CI: -0.47-0.33, P = 0.646) and quality of life (SMD 1.06, 95% CI: -0.03-2.14, P = 0.060). The benefits were consistent across different photobiomodulation protocols for oral mucositis and quality of life. CONCLUSIONS: Photobiomodulation appears to be a promising supportive care intervention, reducing the risk of severe mucositis and oral pain, while potentially improving salivary flow rates and preserving quality of life in patients with head and neck cancer. However, the certainty of the evidence ranged from very low to low and most included studies presented a high risk of bias; therefore, these findings should be interpreted with caution.