The response of atelectasis from lung cancer to radiation therapy.

Between January 1981 and June 1983, 33 newly diagnosed patients with lung cancer presented with radiological findings of atelectasis. These patients were treated by primary radiation therapy, with doses ranging from 1200 to 6000 cGy. The response of atelectasis to radiation therapy was established on the basis of follow-up chest roentgenograms. Of the 28 patients with non-small cell carcinoma of lung, there were 17 (61%) who had improvement of the atelectasis. Among these, 13 patients were treated with doses ranging from 5000 to 6000 cGy in 5 to 8 weeks; 9 of these (70%) responded. By histological subtype, the numbers, though small, show that three of eight patients with adenocarcinoma responded, as compared to 2 out of 4 with large cell undifferentiated carcinoma and 12 of 16 patients with squamous cell carcinoma. In patients treated by more than 5000 cGy, four of eight (50%) patients with squamous cell carcinoma had a complete response and three (37.5%) had a partial relief of atelectasis, for a total response of 87.5%. The study indicates the importance of radiation therapy in the management of atelectasis caused by primary lung cancer.