[Radiation pneumonitis in the x-ray picture following megavoltage irradiation using the Neptune 10 p. linear...

For 105 patients with healthy lungs (76 breast carcinomas, 29 testicular tumors) irradiated from 1981 to 1983 with the linear accelerator Neptune 10p. the pulmonary effects of irradiation were monitored over several years. The true dose applied for breast carcinomas was 46 Gy (2 Gy per fraction), for testicular tumors 40 Gy were applied in the mediastinal field. 9% of the patients showed excessive infiltrations, 18% radiation pneumonitis of medium degree. In 35% of the patients slight infiltrations were found. The course of the pneumonitis was, according to its stage, regular. After a latency period 30 days post irradiation the early stadium occurs. Florid pneumonitis develops between the 45th and 90th day after irradiation. Extended radiographic effects occur up to 10 days earlier. Through a period of pneumonitis with pronounced shrinkage fibrosis develops. By CT-based individual radiation planning the pulmonary radiation reaction can be significantly reduced. The differential diagnostics of radiation effects and metastases is discussed.