International Journal of Radiation Oncology*Biology*Physics
Clinical investigation: lungLong-term changes in pulmonary function tests after definitive radiotherapy for lung cancer☆
Introduction
Lung cancer is the most common cause of cancer death in the United States, frequently presenting with locally advanced disease 1, 2. Definitive thoracic radiotherapy (RT), typically combined with chemotherapy, is used to treat patients with unresectable disease. The usual doses of RT are often associated with changes in pulmonary function tests (PFTs) and, in some cases, clinical pneumonitis (3). Previously published studies have reported PFT changes 1 year after definitive RT 4, 5. Longer follow-up results are available only for patients treated postoperatively (6). We have prospectively followed a large cohort of patients with malignancies whose RT fields encompassed portions of the thorax to assess, and try to predict, lung function changes. We report the changes in PFTs after definitive RT for lung cancer in patients with approximately ≥2 years follow-up data.
Section snippets
Methods and materials
Since 1992, we have been conducting a prospective clinical study to relate RT-induced changes in lung function with dosimetric and functional metrics. The study was open to all patients receiving thoracic RT with an expected survival ≥12 months, willing to return for regular follow-up evaluations, and without a history of prior RT. The Duke University Medical Center Institutional Review Board approved the study, and all patients provided written informed consent. Between 1992 and 2000, 128
Results
At 6 months, a decline was recorded in the median FEV1, FVC, and DLCO (89%, 89%, and 92% of baseline, respectively; Fig. 1). By 1 year, the results were closer to baseline (FEV1was back to 100%, FVC was at 105%, and DLCO at 90%). Graphs of the entire data set show the median values having a greater recovery than the results for the individual patients, which demonstrate more of a plateau (Fig. 2, Fig. 3, Fig. 4). However, over time, the reduction in all three parameters continued. From 1
Discussion
RT caused a decline in PFTs 6 months after treatment with a partial recovery, or plateau, by 12 months. The recovery of the median values observed was likely due to the limited data points at 1 year. Beyond 1 year, a continued decline occurred in PFTs, suggestive of progressive/evolving RT-induced lung injury. Of the 7 patients with data ≥3 years, all had a progressive decline in PFTs. “Late” pulmonary symptoms also occurred in these patients.
That some patients had improvement in pulmonary
References (15)
Nonsurgical management of non-small-cell lung cancer
Hematol Oncol Clin North Am
(2001)- et al.
Toxicity of thoracic radiotherapy on pulmonary function in lung cancer
Lung Cancer
(1994) - et al.
The effect of irradiation on lung function and perfusion in patients with lung cancer
Int J Radiat Oncol Biol Phys
(1995) - et al.
Effect of postoperative radiotherapy on changes in pulmonary function in patients with stage II and IIIA lung carcinoma
Int J Radiat Oncol Biol Phys
(1990) - et al.
Common toxicity criteriaversion 2.0. An improved reference for grading the acute effects of cancer treatment: Impact on radiotherapy
Int J Radiat Oncol Biol Phys
(2000) - et al.
Radiation-induced hypoxia may perpetuate late normal tissue injury
Int J Radiat Oncol Biol Phys
(2001) - et al.
The response of the urinary bladder, urethra, and ureter to radiation and chemotherapy
Int J Radiat Oncol Biol Phys
(1995)
Cited by (0)
- ☆
Supported in part by NIH Grant CA 69579.