Effectiveness of low-level laser therapy for oral mucositis prevention in patients undergoing chemoradiotherapy for the treatment of head and neck cancer: A systematic review and meta-analysis

•Low-level laser therapy was effective in preventing the incidence of oral mucositis;•Better oral mucositis prevention on the early weeks of study;•Laser therapy was not effective in preventing pain incidence. Oral Mucositis is a frequent and debilitating inflammatory complication in patients with head and neck malignancies and may lead to unplanned treatment interruptions due to intense pain and dysphagia. This systematic review with meta-analysis was performed to determine the effectiveness of low-level laser therapy in preventing oral mucositis in this context. The following databases were searched through September 2018, with last search performed on May 2019, for clinical trials: MEDLINE via PubMed, Cochrane Central, Scopus, Lilacs, ISI Web of Science and SIGLE via Open Grey. From 14,525 records, 4 studies were included in the review and 3 studies were included in meta-analysis. Data from 500 patients (mean age of 53.595 and 54.14 for intervention and control groups, respectively) were analysed. Meta-analysis showed that laser therapy prevents oral mucositis incidence in 28% and 23% of cases during the third and fourth follow-up week, respectively, in comparison to a placebo-treated control group. There was no statistically significant difference the prevention of pain; dysphagia and quality of life were not analysed due to missing. Laser therapy was effective in preventing oral mucositis from the 15th to the 45th days of chemoradiotherapy. However, new primary studies with low risk of bias are needed so a higher scientific evidence can be obtained.