Early changes in pulmonary function after stereotactic body radiotherapy for lung oligometastases

Area of Science:

• Pulmonary Medicine
• Radiation Oncology
• Oncology

Background:

• Stereotactic body radiotherapy (SBRT) is a treatment for limited metastatic disease.
• Early pulmonary function changes after SBRT for lung oligometastases require evaluation.
• Identifying predictors of meaningful pulmonary decline is crucial for patient management.

Purpose of the Study:

• To assess early pulmonary function changes post-SBRT in lung oligometastases.
• To identify predictors of clinically significant pulmonary function decline after SBRT.

Main Methods:

• Retrospective analysis of 55 patients with 71 lung metastases treated with SBRT.
• Pulmonary function tests (PFTs) including FEV1, FVC, FEV1/FVC, VC, and DLCO measured pre- and 3-months post-treatment.
• Clinically meaningful decline defined as ≥10% from baseline; associations analyzed with Chi-square and Kaplan-Meier methods.

Main Results:

• Mean FEV1 and FEV1/FVC ratio showed statistically significant declines (P=0.007 and P=0.04, respectively).
• No significant changes observed in FVC, VC, or DLCO.
• Clinically meaningful declines were linked to non-small cell lung cancer (NSCLC) histology, elevated leukocyte count, larger metastasis diameter (≥12.5 mm), and age (≥65 years).

Conclusions:

• SBRT leads to modest early airflow parameter declines in lung oligometastases patients.
• Lung volumes and gas exchange remain largely unaffected early post-SBRT.
• NSCLC histology, systemic inflammation markers, metastasis size, and patient age are potential predictors for identifying high-risk individuals.