[A case of radiation myelitis following radiotherapy in lung cancer]

A case of radiation myelitis developed 1 year and 5 months after radiotherapy for lung cancer is reported. A 75-years old male was given a dose of 70 Gy to the tumor with a fraction dose of 2 Gy, 5 times per week. He developed the weakness and disturbance of sense in bilateral lower extremities, which gradually worsened in spite of a variety of treatment. Some discussions on tolerance dose, fraction dose and fraction number are made as well as technique of irradiation.