High-resolution computed tomography of the lungs in irradiated breast cancer patients.

Fifty-five breast cancer patients underwent high-resolution computed tomography (HRCT) of the lungs before, 8-12 weeks, 6, 9 and 12 months after adjuvant radiotherapy. During the follow-up time, 17 of them (30%) were found to develop minimal parenchymal alterations in the irradiated lung volume by HRCT evidence. The parenchymal alterations were classified by five scores. Scores 1-4 described chronic radiologic changes, score 5 acute radiologic changes. Three patients presented with acute radiologic changes (alveolar filling) within the first 3 months after radiotherapy. Two did not show any abnormalities at later follow-ups. Chronic radiologic fibrosis (15 patients) was not seen before the sixth month post irradiation except in 2 cases. There was no correlation between acute changes and chronic fibrosis. None of these changes were seen at a lung dose of less than 40 Gy. The appearance of interstitial pulmonary lesions secondary to breast irradiation was comparable to that of other interstitial diseases of the lungs. Chest radiographs were normal in all patients. None of the 55 patients presented with clinical symptoms.