Data sources: Medline, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CINHAL, Web of Science, Scopus, LILACS, Conference proceedings of the International Society of Paediatric Oncology, American Society of Clinical Oncology, American Society of Hematology, American Society of Pediatric Hematology and Oncology, and Multinational Association of Supportive Care in Cancer and the reference lists of identified studies.
Study selection: Two reviewers independently selected studies for inclusion with randomised controlled trials (RCTs) and quasi-RCTs being considered.
Data extraction and synthesis: Data were extracted using a specifically developed form and study quality was assessed using the Cochrane risk of bias tool. Dichotomous outcomes data were synthesised using the risk ratio (RR) and 95% confidence interval (CI). Continuous outcomes measured using different scales were synthesised using the standardised mean difference (SMD) while those using the same scale were synthesised using the weighted mean difference (WMD).
Results: Eighteen RCTs involving 1144 patients were included. Four trials were considered to be at low risk of bias across all domains. Prophylactic LLLT reduced the overall risk of severe mucositis (risk ratio (RR) 0.37, 95% confidence interval (CI) 0.20 to 0.67; P = 0.001). Compared to placebo/no therapy LLLT also reduced the following outcomes; severe mucositis at the time of anticipated maximal mucositis RR = 0.34, (95% CI; 0.20 to 0.59); overall mean grade of mucositis SMD -1.49, (95% CI; -2.02 to -0.95); duration of severe mucositis WMD -5.32, 95% (CI; -9.45 to -1.19) and incidence of severe pain (RR 0.26, 95% CI; 0.18 to 0.37).
Conclusions: Prophylactic LLLT reduced severe mucositis and pain in patients with cancer and HSCT recipients. Future research should identify the optimal characteristics of LLLT and determine feasibility in the clinical setting.