The aim of this study was to investigate the incidence of radiation pneumonitis in patients with non-small-cell lung cancer treated with concurrent thoracic radiotherapy and erlotinib.

Patients with inoperable stages IIIA to IV non-small-cell lung cancer who were treated with concurrent thoracic radiotherapy and erlotinib were analyzed. The incidence of radiation pneumonitis was evaluated using the Common Toxicity Criteria (CTC) 3.0 Grading System. The development of grade 2 or higher radiation pneumonitis was the study end point.

Among the 24 patients analyzed, there were nine developed radiation pneumonitis of grade 2 or higher (37.5%), including four cases of grade 2 radiation pneumonitis (16.7%), two of grade 3 radiation pneumonitis (8.3%), and three of grade 5 radiation pneumonitis (12.5%). Three patients developed fatal pneumonia and died of bilateral lung radiation pneumonitis.

Radiation pneumonitis should be considered in patients treated with concurrent thoracic radiotherapy and erlotinib.