Efeitos da fotobiomodulação na xerostomia e hipossalivação durante a radioterapia em pacientes portadores de carcinoma de células escamosas na região de cabeça e pescoço – um ensaio clínico controlado randomizado

Abstract

Squamous cell carcinoma is the most common type of cancer in the head and neck region, representing 90% of malignant neoplasms that affect the oral cavity. As the main modalities of cancer treatment, surgery, chemotherapy and/or radiotherapy, which may or may not be associated. Any choice of treatment, harmful effects may cause damage, reversible or not, in organs at risk, such as salivary glands, which are highly radiosensitive. In the first days of radiation, cells will be affected, severely impairing water production, which reduces salivary flow, leading to hyposalivation, or the subjective sensation of dry mouth, xerostomia. Saliva is important for oral cavity homeostasis and changes in salivary flow interfere with basic oral functions, impacting the individual's quality of life. There are several proposed treatments, including photobiomodulation. However, the lack of a precise protocol makes it difficult to obtain scientific evidence capable of generating effective therapeutic protocols. The present study aims to evaluate the effect of photobiomodulation in the treatment of xerostomia and hyposalivation in patients with squamous cell carcinoma in the head and neck region. As a method, a single-blind, parallel, randomized, two-arm controlled clinical trial was performed following Consort guidelines. The research was registered in the Brazilian Registry of Clinical Trials ReBEC with UTN nº. U1111-12599-9624 ∕ RBR-9bt3cbj, and performed at Hospital Dilson Godinho de Quadros, in the Municipality of Montes Claros, between December 2018 and March 2021. Of 111 participants, 85 were included in the research, randomly and randomly divided in the intervention group (n = 41) or without intervention (n = 44). A portable DUO laser device was used, semiconductor light emitter (GaAIAs and InGaAIP), laser optical power of 100 mW, laser beam area of pen nozzle output of 3 mm2, spot area 0.030 cm2, continuous equipment operation, with a combination of two wavelengths (660 nm and 808 nm). Energy doses of 9 J per point of each wavelength were delivered to the tissues separately, energy density 300 J∕ cm2, power density 3.33 W∕ cm2, form of punctual irradiation, with light incidence at 90 ͦin tissue, in major salivary glands, twice a week during radiotherapy. As a primary outcome, a reduction in xerostomia and hyposalivation was expected, and a secondary outcome, a decrease in anxiety and depression scores. The results showed no statistical differences between the groups for objective reduction of salivary flow, hyposalivation, volume, density and pH of saliva. Regarding the symptom self-reported by the patient, dry mouth sensation, scores obtained through the xerostomia questionnaire were not statistically different between the groups compared. Regarding the scores on the anxiety and depression inventories, no differences were found either, corroborating previous findings and concluding that photobiomodulation for xerostomia and hyposalivation, with the protocol proposed by this study, does not show statistical difference between the groups that received or not intervention soon after completion of radiotherapy treatment.