The Effect of Concurrent Radiochemotherapy on Pulmonary Function Tests: Can Radiation Pneumonitis be Predicted?
1Department of Radiation Oncology, Dr. Suat Seren Chest Diseases and Surgery Training and Research Hospital, İzmir-Turkey
2Department of Chest Diseases, Dr. Suat Seren Chest Diseases and Surgery Training and Research Hospital, İzmir-Turkey
DOI : 10.5505/tjo.2019.1873 OBJECTIVE
The aim of the present study was to evaluate the extent of change in pulmonary function tests (PFTs) in early 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 locally advanced non-small cell lung cancer (NSCLC).

Patients 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 parameters before RCT; 1, 6, and 12 months after RCT; response rates; progression-free survival (PFS); and 5-year overall survival (OS). PFT parameters at 1, 6, and 12 months after RCT were compared with the same patients" baseline values. RP was assessed both clinically and radiologically.

A 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 forced expiratory 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 was found to be predictive of RP except the baseline DLCO; patients who had a baseline DLCO value <65% (52%?75%) developed RP in contrast to patients who had baseline DLCO value >75% (71%?95%) (p=0.023).

There has been prominent and persistent decrease in PFT after RCT. However, the clinical outcome of this finding has to be evaluated. Further prospective studies with larger scales are needed to verify the predictive value of baseline DLCO on the development of RP. Keywords : Non-small cell lung cancer; pulmonary function tests; radiochemotherapy