Biodegradable seeds of holmium don´t change neurological function after implant in brain of rats.

Abstract

Aim: To evaluate the surgical procedure and parenchymal abnormalities related to implan-tation of ceramic seeds with holmium-165 in rats’ brain.Background: An effective method of cancer treatment is brachytherapy in which radioactiveseeds are implanted in the tumor, generating a high local dose of ionizing radiation thatcan eliminate tumor cells while protecting the surrounding healthy tissue. BiodegradableHo166-ceramic-seeds have been addressed recently.Methods and materials: The experiments in this study were approved by the Ethics Com-mittee on Animal Use at the Federal University of Ouro Preto, protocol number 2012/034.Twenty-one adult Fischer rats were divided into Naive Group, Sham Group and Group forseed implants (ISH). Surgical procedures for implantation of biodegradable seeds were doneand 30 days after the implant radiographic examination and biopsy of the brain were per-formed. Neurological assays were also accomplished to exclude any injury resulting fromeither surgery or implantation of the seeds.Results: Radiographic examination confirmed the location of the seeds in the brain. Neuro-logical assays showed animals with regular spontaneous activity. The histological analysisshowed an increase of inflammatory cells in the brain of the ISH group. Electron microscopyevidenced cytoplasmic organelles to be unchanged. Biochemical analyzes indicate there was neither oxidative stress nor oxidative damage in the ISH brain. CAT activity showed no difference between the groups as well as lipid peroxidation measured by TBARS. Conclusions: The analysis of the data pointed out that the performed procedure is safe as no animal showed alterations of the neurological parameters and the seeds did not promote histological architectural changes in the brain tissue.