Fatal pneumonitis associated with postoperative intensity-modulated radiotherapy in lung cancer: Case report and review

Radiation pneumonitis (RP) is the most significant complication of acute treatment-related toxicities in lung cancer. Intensity-modulated radiotherapy (IMRT) with inverse planning enables us to achieve the desired dose distribution. However, there are many high-risk procedures associated with lung irradiation, including chemotherapy and surgery. We report a case of fatal treatment-related pneumonitis, where the patient had undergone postoperative IMRT for lung cancer. Following completion of radiotherapy, the patient developed progressive dyspnea. A chest computed tomography (CT) scan revealed the presence of diffuse reticular interstitial processes and honeycombing in both lungs. The fibrotic change in both lungs in a transverse view was compatible with low-dose irradiation of non-target organs at risk. Acute radiation pneumonitis was diagnosed. For patients receiving postoperative IMRT, low-dose irradiation volumes should be considered for lungs, as well as strict dose-volume histogram (DVH) parameters.