Efeito da oxigenação hiperbárica no osso submetido e não submetido à radiação ionizante: análise macroscópica e mecânica em tíbias de rato

Abstract

Radiation therapy is widely indicated for cancer treatment. Hyperbaric oxygen has been used to assist would healing in the treatment of complications associated with the effects of radiation. The tibiae of twenty male healthy Wistar rats, weighing 300 to 400g were randomly divided into Control (Right tibiae: n=5), Radiotherapy (Left tibia: n=5), Hyperbaric Oxygen Therapy (Right tibiae: n=5) and Radiotherapy + Hyperbaric Oxygen Therapy (Left tibiae: n=5) groups. Radiotherapy was made on the left tibiae in all animals. Treatment with HBO started 30 days after radiotherapy and was conducted daily in 10 animals until euthanasia. After 3 or 7 days, all the animals were euthanized and tibiae removed for Macroscopic and Biomechanical analysis. Length and thickness values were greater in non-irradiated specimens when compared to irradiated. A significant increase in length values was observed in the Radiotherapy group when compared day 3 and day 7. There was also an increase in AP thickness over time in the groups Radiotherapy and Radiotherapy + Hyperbaric Oxygen Therapy. Irradiated bone tended to reduce the force, work to failure and stiffness compared with non-irradiated bone, even with HBO treatment, with significant difference observed for Fmax between Control group when compared to Radiotherapy at day 7. The results indicate that ionizing radiation has altered bone growth and strength. Although there was a tendency for improvement of the bone conditions after HBO, this therapy was not enough to compensate for the damages caused by the ionizing radiation in the bone.