Red, infrared, and simultaneous laser-wavelengths irradiation effects on 5-fluorouracil-induced oral mucositis in hamsters.

The association of more than one wavelength for photobiomodulation therapy (PBMT) to treat oral mucositis (OM) is unusual in the literature. Thus, this study aims to compare the simultaneous irradiation effects with their isolated application to treat OM. In order of that, 48 male Syrian hamsters were divided into 4 groups: Chemotherapy (Ch), which received only a OM induction protocol (5-fluorouracil chemotherapy and superficial oral mucosa scratches); red laser (RL), which received the OM induction and a PBMT protocol at 660 nm; infrared laser (IRL), which received the OM induction, and a PBMT protocol at 808 nm; and the RL + IRL group, which received the simultaneous application, of 660 and 808 nm wavelengths. Clinical (OM grade classification), histological (light microscopy analysis with H&E and collagen staining), immunohistochemical (TNF-α expression), and biochemical (TNF-α and hydroxyproline concentration) analyzes were performed after 7 and 10 days. Mainly on the 10th day, the RL and IRL groups showed lower OM grades and faster microscopic repair process, with greater expression of collagen fibers and lower TNF-α levels, besides the higher hydroxyproline concentrations, mainly in comparison with the Ch group. In conclusion, in this study, the simultaneous protocol did not present superior results than the isolated irradiations.

Photodynamic therapy to control oral candidiasis in a pediatric patient undergoing head and neck radiotherapy.

Candida albicans is an opportunistic yeast of the oral microbiome which can cause candidiasis in systemically susceptible individuals, such as those undergoing cancer treatment. The local management of the oral lesions is challenging and may be significantly improved with photodynamic therapy (PDT). PDT consists of an association of light with a photosensitizing agent and oxygen, whose interaction produces reactive oxygen species capable of reducing non-specific microbial contamination without causing side effects. This study aimed to report a case in which oral candidiasis was managed with PDT. A 12-year-old male patient undergoing head and neck radiotherapy (HNRT) for Undifferentiated Mesenchymal Neoplasm presented with dysgeusia, oral pain, and yeast infection on the 13th session of HNRT. The patient used topical antifungals for 30 consecutive days with no lesion or symptom remission. PDT was then proposed and the lesion was healed after a single PDT session, with no further clinical signs of infection and return to normal oral function. Local and non-invasive management of oral candidiasis is of utmost importance for immunocompromised patients, with good acceptability, no systemic side effects, and no drug interactions.

Wound healing process with different photobiomodulation therapy protocols to treat 5-FU-induced oral mucositis in hamsters.

OBJECTIVES: The aim of this study was to analyze the effects of three different Photobiomodulation Therapy (PBMT) protocols in the treatment of 5-fluorouracil-induced oral mucositis in hamsters. DESIGN: 60 hamsters were divided into five groups: group "C", which did not receive oral mucosa scratching, 5-fluorouracil (5-FU) or PBMT; group "Ch", which received anesthesia, superficial oral mucosa scratching and 5-FU (oral mucositis induction); and three groups that received oral mucositis induction and a PBMT protocol: groups ChLI, ChLII and ChLIII that received 0.24 J (one point), 1 J (one point) and 1.2 J (five points of 0.24 J) of energy, respectively. The laser equipment used had λ = 660 nm and 0.04 cm2 of spot area (0.226 cm diameter). The animals were euthanized on days 7 and 10 of the experiment, and their oral mucosas were removed for histological (light microscopy and collagen staining), immunohistochemical (NF-kB and TNF-α), and biochemical (TNF-α, NF-kB and hydroxyproline) analysis. RESULTS: Group ChLI (less energy), showed the most accelerated repair rates and a lower concentration of inflammatory biomarkers than group Ch. Comparing the three PBMT protocols for treatment of 5-FU-induced oral mucositis in hamsters, the one with low energy (0.24 J) showed better results, regarding reduction of inflammatory biomarkers and tissue repair, than the ones with higher energy (1 and 1.2 J).

Local management of neutropenic ulcer in a patient under breast cancer treatment.

Neutropenic ulcers are characterized by regular margins with a yellowish membrane, and are usually associated with severe pain and signs of inflammation due to opportunistic infections. Considering the immunosuppressed condition of these patients, local management of these lesions is a challenge. Antimicrobial photodynamic therapy (aPDT) is the association of light, which can be a low-power laser, with a photosensitizing agent and oxygen, whose synergy produces reactive oxygen species capable of reducing non-specific microbial contamination without causing side effects. The aim of this paper is to report a case of oral neutropenic ulcer treated with aPDT. A 50-year-old diabetic woman undergoing breast cancer treatment, presented with a malodorous malodorous and painful ulcer, which limited her basic oral functions. It was located in the maxillary alveolar ridge in the left first upper molar region and did not present bone involvement. Blood tests showed grade 2 of neutropenia. Thus, conservative treatment with aPDT technique was proposed. After one week, the lesion showed an improvement and pain had halved. The region was totally healed after three weeks. Local and non-invasive management of these lesions is of utmost importance for immunosuppressed patients, because it avoids systemic side effects and bacterial resistance resulting from overuse of antibiotics.