The role of radiation therapy in the treatment of small cell carcinoma of the lung

A retrospective analysis was made on 40 consequtive patients treated for small cell carcinoma of the lung from April 1972 through March 1985. Twenty-six patients were diagnosed as having limited disease and 14 as extensive disease. The initial treatment was radiation (n = 18), radiation + chemotherapy (n = 12), chemotherapy (n = 9), and surgery (n = one). In none of the patients, who received irradiation of less than 40 Gy with or without chemotherapy, did tumors disappear at the time of completion of initial treatment. In the 23 others irradiated with 40 Gy or more, 22 had the disappearance of tumors. In the remaining one patient in whom tumor disappearance was not attained with 40 Gy, it took 3 months after intensive chemotherapy up to the beginning of radiation. Autopsy performed in 15 patients revealed distant metastases in all the patients. Complete regression was observed in the primary site in 4 patients treated with 54 Gy or more for tumors 5 to 6 cm in diameter. The results suggest the following: (1) The total radiation dose should not be reduced even when chemotherapy is combined with radiation; (2) It is recommended that both radiation and chemotherapy be undertaken simultaneously, or radiation, if used after chemotherapy, be started as soon as possible; (3) The total radiation dose necessary for the local control is considered to be 50 Gy or more. (Namekawa, K.)