Efeitos da laserterapia de baixa potência na cavidade oral em pacientes com tumores não hematológicos em tratamento quimioterápico

Abstract

Cytotoxic chemotherapy is one of the treatments used for solid tumors, associated with radiotherapy or surgery. Chemotherapy is associated with several adverse effects such as alopecia, impaired immune response, nausea, vomiting, diarrhea, oral mucositis and others. Oral mucositis, clinically, ranges from erythema to ulcerations throughout the oral mucosa, associated with severe pain, difficulty in food and water intake. Due to the worsening of oral mucositis the patient may progress to malnutrition, dehydration, infection, hospitalization, postponement or discontinuation of antineoplastic treatment. Preventive and therapeutic actions have been proposed. Low-power laser therapy in the range of 600nm to 650nm (red) and in doses between 2 and 3 J / cm2 , is effective in preventing oral mucositis induced by radiotherapy for tumors in the head and neck due to the anti- inflammatory, analgesic and tissue repair. There is little literature on low-power laser therapy in chemotherapy for other solid tumors. It is usually described in association with chemotherapy for hematological cancers using high-dose chemotherapy, where oral mucositis is usually more severe and lasting. In view of these observations, it is proposed to evaluate the capacity of prevention of laser therapy, at a frequency of 630nm, with a dose of 2J / cm2 , for the prevention of oral mucositis induced by chemotherapy specifically for nonhaematological tumors. For this study, 287 medical records of patients undergoing chemotherapy treatment were analysed in different locations of solid tumors, such as the breast, gastrointestinal tract, liver, pancreas and others. Epidemiological data, total leukocytes and neutrophils, general side effects, development of oral mucositis and degree, and the performance of low-power laser therapy to prevent oral mucositis were collected. To evaluate the possible involvement of oxidative stress in the development of oral mucositis and in the action of laser therapy, in 35 patients, peripheral blood was collected prior to the start of chemotherapy treatment and in the last treatment cycle. The enzyme superoxide dismutase (SOD), an important antioxidant enzyme in the process related to oxidative stress (imbalance between oxidation and antioxidant actions), was analysed through blood serum. According to the results presented in this study, low power laser therapy in the proposed protocol is efficient in reducing the development of oral mucositis in patients under chemotherapy (p = 0.0001), and able to reduce the severity of oral mucosal lesions, in patients who developed mucositis after the use of the laser for prevention