[Pulmonary radioreaction demonstrated by x-ray pictures (author's transl)]

X-ray radiographs of the thorax of 119 patients suffering from Morbus Hodgkin (period of therapy VI/1974-III/1979) which have been taken during radiotherapy and at routine follow up examinations have been analysed with regard to temporal progress and extent of the pulmonary radioreaction after standardised mantle-field irradiation with a 4-MeV linear accelerator, extended-field satellite technique and tumor doses of 40-46 Gy. After a characteristic latency period without radio-morphological reaction the patients on average showed 12 weeks after beginning of irradiation signs of a beginning pneumonitis (phase I), after 15 weeks a florid pneumonitis (phase IIa), and after 20 weeks a florid pneumonitis with beginning shrinkage (phase IIb). After 5-9 months (average level 34 weeks) the pulmonary radioreaction was complete after having reached a steady paramediastinal lung fibrosis (phase IV). Classifying the radioreaction into 3 degrees of gravity a light pneumonitis was found in 44%, a medium one in 29%, and a severe pneumonitis in 16% of the cases. For clinical use it is important to know that after beginning shrinkage new expansion of mediastinum and/or of peripheral parenchymal shadows cannot be radioreactions. Primarily these new changes have to be interpreted as recurrence.