Pulmonary function abnormalities in children treated with whole lung irradiation

BACKGROUND: We sought to determine the prevalence of abnormal pulmonary function tests (PFTs) in a cohort of children who had received whole lung irradiation (WLI) for treatment of metastatic disease. PROCEDURE: This was a retrospective (1988-2003) chart review that included all children treated at our institution with WLI who had undergone PFT. Data abstracted included oncologic diagnosis, radiation dose and fractionation, spirometry (FVC, FEV1, FEV1/FVC, FEF25%-75%), plethysmography (TLC, FRC, RV, RV/TLC), diffusing capacity (DLCO), and respiratory muscle strength (MIP, MEP). PFTs were normalized according to standard deviation (Z) scores. RESULTS: Thirty patients were identified who had one or more PFT. The incidence of mild, moderate, or severe reductions in FEV1 was 30%, 10%, and 10%, respectively, with 50% having normal FEV1. Seventeen percent of patients had mild reduction in total lung capacity (TLC), while 13% and 30% had moderate or severe reductions. Thirty-eight percent had mild reductions in diffusing capacity, while 29% and 14% had moderate or severe reductions. CONCLUSIONS: Pulmonary function abnormalities were common in this cohort of children treated with WLI, and may be progressive in nature. Further studies are warranted to identify patients at highest risk.