Primary Exposure: Pulmonary Toxic Therapy
Agents with significant pulmonary toxic properties identified from the literature include pulmonary radiation and select chemotherapy agents (bleomycin, busulfan, carmustine, lomustine and cyclophosphamide). While cyclophosphamide is not traditionally considered by oncologists to be a pulmonary toxic chemotherapy agent, it is well-reported to cause multiple lung sequelae including early and late onset pneumonitis and pulmonary fibrosis13. We stratified thoracic radiation into high volume or low volume depending on the volume of lung included in the radiation field. Mantle, mediastinum, whole lung and total body irradiation were considered high-volume thoracic radiation, while neck, abdominal, inverted Y, para-aortic, flank or supraclavicular radiation were considered low volume thoracic radiation. Internationally approved standardized pediatric oncology treatment protocols based on cancer type and extent of disease were used for both chemotherapy and radiation therapy. These were consistent throughout the study time period.