Low-level laser therapy dosimetry most used for oral mucositis due to radiotherapy for head and neck cancer: a systematic review and meta-analysis.

Dosimetry for low-level laser therapy (LLLT) depends on several parameters, such as target tissue type, lesion type and laser equipment used. This study aimed to determine the most used LLLT dosimetry for the treatment and prevention of oral mucositis (OM) resulting from radiation therapy (RT) in head and neck cancer patients (HNCP). This research was conducted according to the PRISMA guidelines using the PICO framework. After extensively searching PubMed, Web of Science, Embase, Scopus, BVS and Cochrane Library databases, we found 130 records and selected 7 studies, involving 363 HNCP with an average age of 60.6 years who received RT. Briefly, sites affected by tumors were the following: oral cavity (170), oropharynx (91), throat (42), larynx (32), nasopharynx (11), hypopharynx (9), and in 8 cases, sites were not reported. These studies used several classifications for OM (RTOG/EORTC, WHO, NCI-CTC) and pain (NRS, VAS and modified VAS). These various researchers performed the LLLT punctual application of different forms using several protocols making analysis difficult. However, LLLT was effective regardless of the parameters used (632.8 nm to 685 nm, 1.8 J/cm2 to 3.0 J/cm2, 10 mW to 60 Mw, 0.8 J to 3.0 J). The meta-analysis showed a better results with preventive LLLT 660 nm, 3.8 J/cm2, 15 mW; 0.15 J compared to preventive LLLT 660 nm, 1.3 J/cm2, 5 mW; 0.05 J (OMS: p = 0.03; NCI-CTC: p = 0.027). We conclude that there is, as of yet, no evidence of better laser dosimetry being more effective. Thus, randomized clinical trials to determine which doses of LLLT are most appropriate for treating and preventing OM due to RT are lacking and should be further investigated.