Oncological safety of the use of intraoral and extraoral photobiomodulation in patients with oral cavity and oropharyngeal squamous cell carcinoma

Abstract

Aims: To assess, at clinical and molecular levels, the impact of prophylactic low-level laser therapy (photobiomodulation) for oral and oropharyngeal mucositis (OM) in the survival rates of patients with oral cavity and oropharyngeal squamous cell carcinoma (OSCC). Patients and Methods: 120 patients diagnosed with OSCC that will initiate curative protocols of adjuvant radiotherapy (RT) or chemoradiotherapy (CRT) will be prospectively assessed. Patients will be randomly allocated into four groups; Intraoral prophylactic photobiomodulation (n=30) (InGaAlP; 660 nm, 40 mW, energy density of 10 J/cm2, 0.4J of energy/spot; 10 s/spot, 4mm2 spot size); Extraoral prophylactic photobiomodulation (n=30) (LED 69 diode, 34x660 nm (10 mW) and 35x850 nm (30 mW), 1390 mW, energy density 50 mW /cm2, 3.0J of energy/cm2, 60s/spot, spot size (? cm2 ); Placebo intraoral photobiomodulation sham laser (n=30) and Placebo extraoral photobiomodulation sham laser (n=30). OM degree and OM associated pain will be assessed daily during the RT (NCI, Version 4.0, 2010; WHO, 1975 e VAS). The impact of the photobiomodulation will be evaluated quarterly during 18 months following RT conclusion, regarding the following oncological outcomes: local recurrences, development of second primary tumors, mean time of disease free survival and overall survival. For the analysis of the impact of photobiomodulation in molecular biomarkers of carcinogenesis, whole saliva samples will be collected at 3 different time points (D-1; D30 and D+30RT) followed by proteomic analysis based on mass spectrometry (MS/MS). Expected results: To contribute to a better understanding, in oncological terms, of the safety of photobiomodulation protocols regarding RT induced OM. (AU)