Differences in pulmonary function before vs. 1 year after hypofractionated stereotactic radiotherapy for small...

Area of Science:

• Pulmonary Medicine
• Radiation Oncology
• Oncology

Background:

• Stereotactic radiotherapy (SRT) is an advanced treatment for small peripheral lung tumors.
• Evaluating long-term pulmonary toxicity is crucial for assessing SRT's safety and efficacy.
• Pulmonary function tests (PFTs) are standard for monitoring lung health.

Purpose of the Study:

• To assess the long-term pulmonary toxicity of SRT for small peripheral lung tumors.
• To evaluate changes in PFTs one year after SRT compared to pre-treatment baseline.
• To identify patient and treatment factors influencing pulmonary function post-SRT.

Main Methods:

• 15 patients with 17 small peripheral lung tumors underwent SRT (40-60 Gy in 5-8 fractions).
• PFTs (TLC, VC, FEV1.0, DLCO) were performed before and 1 year after SRT.
• Analysis correlated PFT changes with smoking history (Brinkman index) and radiation parameters (V15-V30, mean lung dose).

Main Results:

• No significant changes were observed in total lung capacity (TLC), vital capacity (VC), or forced expiratory volume in 1 second (FEV1.0) post-SRT.
• The diffusing capacity of lung for carbon monoxide (DLCO) significantly increased by 128.2% from baseline.
• DLCO changes correlated significantly with the Brinkman index, indicating a link with smoking status.

Conclusions:

• SRT for small peripheral lung tumors appears well-tolerated regarding long-term lung function.
• No decline in TLC, VC, or FEV1.0 was noted one year after SRT.
• Improved DLCO in heavy smokers suggests a potential benefit related to smoking cessation post-SRT.