Spontaneous pneumothorax in patients irradiated for Hodgkin's disease and other malignant lymphomas.

A retrospective review of patients treated for Hodgkin's disease or other malignant lymphomas between 1953 and 1988 revealed 10 cases of spontaneous pneumothorax. Nine had Hodgkin's disease whereas one had diffuse histiocytic lymphoma. Ages of the 10 patients ranged from 11 to 54 years, although nine were less than 30-years old. Spontaneous pneumothorax was observed only in patients who had received mantle or mini-mantle radiation therapy (RT). Five patients had concurrent severe parenchymal pulmonary disease including chemotherapy-induced interstitial fibrosis, Varicella pneumonia and severe radiation pneumonitis. Pneumothorax in these patients tended to be severe, bilateral and/or recurrent. All five required chest tube placement. Three of the five also required thoracotomy. RT dose ranged from 3000-7500 cGy, exceeding 4700 cGy in three patients who required a second course of RT which included the involved lung apex. In comparison, the five who did not have concurrent severe lung disease had milder episodes of pneumothorax. Only one required chest tube placement, whereas none required thoracotomy. Pulmonary apex RT dose ranged from 3672-4257 cGy. For Hodgkin's disease patients treated by RT, the frequency of spontaneous pneumothorax in the absence of concurrent pulmonary disease was 2.2%. Limiting analysis to patients in the peak age population of 10-30 years raised the frequency to 3.0%. No RT dose-response effect could be demonstrated, although spontaneous pneumothorax was not observed in patients who received less than 3000 cGy. Spontaneous pneumothorax was not more frequent among patients who also received chemotherapy as compared to those treated only by RT. Exploratory thoracotomy in three cases with severe pulmonary disease revealed subpleural apical blebs and/or dense pleural fibrosis. Unusual aspects in the medical histories of other cases suggest the possibility that patients who develop pneumothorax may have unusually dense pulmonary and/or pleural fibrosis compared to the majority of patients who receive RT for Hodgkin's disease or other malignant lymphomas.