He was undergoing a treatment -- chemotherapy treatments -- and there's a related treatment called brachytherapy, where tiny, radioactive seeds are placed into the body to treat cancerous tumors.
Ele estava submetido a tratamento, tratamentos de quimioterapia, e há um tratamento relacionado chamado braquiterapia, onde pequenas sementes radioativas são colocadas no corpo para tratar tumores cancerígenos.