A Noninvasive Integrative Method for Analyzing Radiation-Induced Lung Injury

The efficacy of radiation treatment for intrathoracic malignancy is limited by the development of radiationinduced lung injury (RILI), which can cause radiation pneumonitis and fibrosis in the lung parenchyma. Several factors influence the risk and severity of RILI, including the radiation dose, the fractionation, the volume of irradiated lung, and whether the patient has pre-existing lung disease or has received systemic agents or prior thoracic radiation.1-3 Radiation pneumonitis usually manifests 1–6 months after completion of radiation, and it may progress to irreversible pulmonary fibrosis. Although radiographic changes sometime manifest with no accompanying symptoms, the classic triad includes dyspnea, cough, and fever, which respond to corticosteroid intervention.2,4 Radiologic findings are imprecise, yielding a broad differential diagnosis that may warrant pathologic verification and could delay initiation of management. Acute changes from radiation pneumonitis consist of a diffuse haze in the treatment region, ground-glass opacity, and consolidation. Late changes include traction bronchiectasis, volume loss, and scarring. A straight-line effect that conforms not to anatomic boundaries but rather to the margins of the radiation port is the most distinctive feature of RILI.4,5 This case report describes a noninvasive integrative method used to carefully analyze radiation pneumonitis in the follow-up evaluation of a patient treated with chest radiotherapy.