Photobiomodulation in the prevention of oral mucositis in blood cancer patients undergoing high-dose methotrexate: preliminary findings of a prospective, randomized, double-blind clinical study

Abstract

Objective

This study aimed to assess the efficacy of photobiomodulation (PBM) in preventing oral mucositis (OM) in adults with blood cancer undergoing high-dose methotrexate (HD-MTX ≥1 g/m²) treatment. Additionally, the correlation between serum creatinine and MTX, urinary pH, and the development and severity of OM were investigated.

Methods

A prospective, randomized, and double-blind study recruited patients before their first cycle of HD-MTX. Participants were assigned to 2 groups: group 1 (prophylactic PBM) and group 2 (placebo), and assessments were conducted at infusion (D0)/D1 (24 h)/D2 (48 h) /D3 (72 h) /D4 (96 h)/D10. Group 1 received PBM (660 nm, 100 mW, spot size 0.028 cm², fluence 10 J/cm² per point/10 s) in the oral mucosa from the first day until D5 post HD-MTX infusion or until MTX plasma concentrations were <5 µmol/L at D1, <1 µmol/L at D2, and <0.1 µmol/L at D3. Serum MTX and creatinine, and urine pH were assessed at D1/D2/D3. OM was classified according to World Health Organization criteria. Logistic regression, Mann-Whitney U, and χ² tests were used to identify predictive factors for OM.

Results

A total of 36 patients were allocated to the PBM or placebo group (50% each). Most patients (66.6%) were female, with mean ages of 39.8 and 39.6 in groups 1 and 2, respectively. Regarding OM, group 2 developed grade 2 earlier at D2 (5.6%), D3 (11.1%), and D4 (50%) compared with group 1, which only developed grade 2 at D4 (5.6%). The Mann-Whitney test for overall OM grade comparison (group 1 vs group 2) at D4 showed a P < .001, and the χ² test demonstrated a P = .003 (grades 0 and 1 vs grades 2/ 3). Elevated creatinine serum levels at D2 postinfusion predicted the incidence of OM. No correlation was found between serum MTX levels, urine pH, and OM.

Conclusion

PBM proves effective in preventing OM and reducing its incidence and severity in patients undergoing HD-MTX protocols. Elevated creatinine serum levels at D2 appear to be a predictor of OM.