Is Acupuncture an Effective Treatment for Radiation-Induced Xerostomia of Patients with Head and Neck Cancer? A Systematic Review and Meta-Analysis

Background: Radiation-induced xerostomia (RIX) stands out as one of the most severe side effects among patients with head and neck cancer (HNC). Given the varied conclusions in previous studies concerning the association between acupuncture, sham acupuncture, or acupuncture combined with standard oral care and therapeutic effects, our aim is to conduct a systematic review to assess the effectiveness and safety of acupuncture in managing RIX in patients with HNC.Methods: Six databases (Cochrane Library, PubMed, EMBASE, China National Knowledge Infrastructure, Chongqing VIP, and WanFang Database) were electronically searched, following the Cochrane manual and adhering to reported Preferred Reporting Item for Systematic Reviews and Meta-Analyses guidelines, from their inception dates to July 1, 2024. Primary randomized clinical trials included in systematic reviews or meta-analyses were identified, with the Xerostomia Questionnaire and Xerostomia Inventory designated as the primary outcomes. Salivary flow rates (unstimulated or stimulated) were defined as secondary outcomes.Results: Eight clinical trials involving 1273 participants were analyzed, with six studies included in the meta-analysis. The results indicate that acupuncture demonstrated a significant improvement in patient-reported xerostomia scores (standardized mean difference [SMD] = -0.20, 95% confidence interval [95% CI] [-0.38, -0.02], I2 = 0%) in comparison to standard care, but did not significantly improve oral dryness symptoms compared with sham acupuncture (SMD = -0.06, 95% CI [-0.29, 0.16], I2 = 25.8%). The merged total showed negative result (SMD = -0.13, 95% CI [-0.27, 0.01], I2 = 8.2%). Additionally, there was no significant difference in stimulated salivary flow rate (SMD = -0.22, 95% CI [-0.58, 0.13], I2 = 0%) and unstimulated salivary flow rate (SMD = -0.19, 95% CI [-0.11, 0.72], I2 = 67.2%). In general, the acupuncture did not cause serious adverse effects.Conclusion: As far as current research is concerned, acupuncture treatment for RIX symptoms in patients with HNC still lacks strong and convincing evidence support. The more scientific research methods and more clinical trials are still needed.