CLINICAL RADIATION PNEUMONITIS AND RADIOGRAPHIC CHANGES AFTER THORACIC RADIATION-THERAPY FOR LUNG-CARCINOMA

BACKGROUND, The authors attempted to determine the incidence of and ri sk factors for clinical radiation pneumonitis in patients treated for lung carcinoma. They also sought to describe the corresponding posttre atment radiographic changes. METHODS, Between 1989-1993, 83 patients r eceived curative radiation therapy For lung carcinoma. Of these, 39 pa tients were treated with definitive radiation therapy, and 44 patients were treated with adjuvant radiation therapy after surgical resection . The median radiation therapy dose was 54 gray (Gy), and the median t reatment area was 182 cm(2). Chest radiographs obtained after radiatio n therapy were reviewed and scored for margin definition, volume loss, and texture quality. RESULTS. A total of 17 patients (20%) developed clinical radiation pneumonitis (CRP). The median radiation therapy dos e for the CRP cohort was 54 Gy, and the median treatment volume was 19 3 cm(2). The median time to onset of symptoms was 3 weeks after radiat ion therapy, and the median duration of symptoms was 10 weeks. Of the 15 evaluable patients, symptoms resolved for 9 patients, improved but persisted for 4 patients, and CRP was fatal for 2 patients. The incide nce of CRP was increased for patients with low performance status, com orbid lung disease, smoking history, low pulmonary function tests, and for those patients who did not undergo a surgical resection. Posttrea tment radiographic changes were common and progressed with time. Radio graphic changes were more pronounced in the CRP cohort, and extended o utside the radiation therapy treatment field in the majority of patien ts (67%). CONCLUSIONS. Clinical radiation pneumonitis developed in 20% of lung carcinoma patients. Risk factors included low performance sta tus, comorbid lung disease, smoking history, low pulmonary function te sts, and the absence of a surgical resection. Posttreatment radiograph changes were common and progressed with time, and typically were not confined to the radiation therapy treatment field. (C) 1998 American C ancer Society.