Respiratory function tests after mantle irradiation in patients with Hodgkin's disease

Pulmonary function tests were performed in 43 patients with Hodgkin's disease before mantle irradiation and at 3, 6, 9, 12 and 15 or more months thereafter. Treatment was given with a telecobalt unit to a total dose of 36 to 42 Gy, the higher dose being reserved for cases with considerable mediastinal involvement. The functional parameters explored included static and dynamic lung volumes, gas exchanges, ventilatory efficiency, and airway resistance. Measured parameters were expressed as a percentage of the pre-treatment value (PTV) in the individual patient. In the whole group, only small variations in the functional indices were observed at 3 to 6 months after mantle irradiation. In patients with normal PTVs a greater variation in static and dynamic volumes was observed at 3 to 6 months after mantle irradiation, with complete recovery thereafter. The gas exchange parameters also showed a similar variation at 3 to 6 months but no recovery was demonstrated in the subsequent examinations. No changes in ventilatory efficiency and airway resistance were observed. In patients with abnormal PTVs, usually presenting large mediastinal adenopathy, all parameters improved after mantle irradiation, and the favourable effect of tumour regression was probably more important than the radiation damage on the pulmonary parenchyma.