Characterizing Pulmonary Function Test Changes for Patients With Lung Cancer Treated on a 2-Institution,...

Area of Science:

• Radiation Oncology
• Pulmonary Medicine
• Medical Imaging

Background:

• Lung cancer treatment often involves radiation therapy, which can cause pulmonary toxicity.
• Four-dimensional computed tomography (4DCT)-ventilation imaging allows for functional avoidance planning to spare healthy lung tissue.
• Reducing pulmonary toxic effects is crucial for improving patient outcomes and quality of life.

Purpose of the Study:

• To evaluate pulmonary function test (PFT) changes in patients with locally advanced lung cancer treated with 4DCT-ventilation functional avoidance radiation therapy.
• To compare PFT metrics before and after chemoradiation.
• To analyze PFT changes in relation to the incidence of radiation pneumonitis.

Main Methods:

• A prospective, multicenter, phase 2 study accrued patients with locally advanced lung cancer receiving chemoradiation.
• Functional avoidance treatment plans were generated using 4DCT-ventilation images.
• Pulmonary function tests (DLCO, FEV1, FVC) were performed at baseline and 3 months post-treatment and compared between groups.

Main Results:

• Fifty-six patients with evaluable PFTs showed mean changes of -11.6% for DLCO, -5.6% for FEV1, and -9.0% for FVC.
• Patients experiencing grade ≥2 pneumonitis had greater mean declines in DLCO (-15.4%) and FEV1 (-14.3%) compared to those with grade <2 pneumonitis.
• While not statistically significant, trends suggested potentially greater PFT preservation with functional avoidance.

Conclusions:

• This is the first study to quantitatively assess PFT changes in a prospective functional avoidance radiation therapy cohort for lung cancer.
• Qualitative comparisons suggest that functional avoidance may lead to less decline in DLCO and FEV1 compared to standard thoracic radiation planning.
• The findings provide data to support the potential pulmonary function benefits of functional avoidance radiation therapy.