The Effect of Concurrent Radiochemotherapy on Pulmonary Function Tests: Can Radiation Pneumonitis be Predicted?

Abstract

The aim of the present study was to evaluate the extent of change in pulmonary function tests (PFTs) inearly and late term after concurrent radiochemotherapy (RCT) and whether the baseline PFTs or percentages of changes in PFTs after RCT would predict radiation pneumonitis (RP) after RCT in locallyadvanced non-small cell lung cancer (NSCLC).METHODSPatients with stage III NSCLC who received RCT between January 2008 and December 2014 were evaluated retrospectively with respect to patients, tumor, and treatment characteristics; PFT parametersbefore RCT; 1, 6, and 12 months after RCT; response rates; progression-free survival (PFS); and 5-yearoverall survival (OS). PFT parameters at 1, 6, and 12 months after RCT were compared with the samepatients’ baseline values. RP was assessed both clinically and radiologically.RESULTSA total of 61 patients were analyzed in the study. Median follow-up was 20 (4–116) months, and PFS was 14(2–122) months. Five-year OS was 18%. All PFT parameters declined after RCT, but only decreases in forcedexpiratory volume in 1 second at 6 and 12 months and in diffusion capacity of the lung for carbon monoxide(DLCO) at 6 months were found to be statistically significant. None of the baseline PFT parameters wasfound to be predictive of RP except the baseline DLCO; patients who had a baseline DLCO value 75% (71%–95%) (p=0.023).CONCLUSIONThere has been prominent and persistent decrease in PFT after RCT. However, the clinical outcome ofthis finding has to be evaluated. Further prospective studies with larger scales are needed to verify thepredictive value of baseline DLCO on the development of RP