Continuous external irradiation.
D000368:Aged; D003037:Cobalt Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D009369:Neoplasms / Q000532:radiotherapy*; D011882:Radiotherapy, High-Energy / Q000379:methods*; D012008:Recurrence
D003037:Cobalt Radioisotopes