Low-level laser in prevention and treatment of oral mucositis in pediatric patients with acute lymphoblastic leukemia.

Objective: The aim of this study was to evaluate the influence of low-level laser therapy (LLLT) on the prevention and treatment of oral mucositis (OM) in pediatric cancer patients taking methotrexate.

Background Data: OM is a very common, potentially severe side effect, caused by treatment with radiotherapy and chemotherapy for cancer.

Methods: Forty patients with acute lymphoblastic leukemia, who received high doses of methotrexate, were distributed into two groups. Group A (Preventive Group) was composed of patients who received preventive laser (red-subgroup A1 or infrared-subgroup A2) for 5 days, beginning on the 1st day of infusion. Group B (Treatment Group) was composed of patients who received laser treatment only if they developed post-chemotherapy mucositis (red-subgroup B1 or infrared-subgroup B2). Laser was used at wavelengths of 660 or 830 nm with output 100 mW, power density 3.57 W/cm(2), spot size 0.028 cm(2), energy of 1 J, resulting in an energy density of 35 J/cm(2) for 10 sec in the prophylactic group, and energy of 2 J, resulting in energy density of 70 J/cm(2) for 20 sec in the therapeutic group.

Results: The percentage of patients who did not develop OM was higher in Group A (60% vs. 25%). In Group B, 3/20 patients developed grade IV OM (15%), and a significant difference was found between the two subgroups at the end of treatment (p=0.019).

Conclusions: Prophylactic laser produced a better outcome than when patients did not receive any preventive intervention, and red laser (660 nm) was better than infrared (830 nm) in the prevention and treatment of OM.