WCLC 2025 - Posters & ePosters-P1.07.34 Toxicity Profile for Connective Tissue Disease Patients Treated With Lung Stereotactic Body Radiation Therapy

P1.07.34 Toxicity Profile for Connective Tissue Disease Patients Treated With Lung Stereotactic Body Radiation Therapy

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This study evaluated the toxicity profile of lung stereotactic body radiation therapy (SBRT) in patients with connective tissue diseases (CTDs), historically considered at higher risk for severe radiation toxicity. Researchers analyzed 118 CTD patients (144 SBRT courses) treated at a single institution between 2006 and 2024. Median patient age was 72 years, 69% were female, and 49% were receiving active medical treatment for their CTDs at the time of SBRT. The cohort included rheumatoid arthritis (47%), systemic lupus (14%), interstitial/idiopathic lung disease (24%), scleroderma (5%), and other CTDs, with 22% having multiple CTDs.<br /><br />Median tumor size was 1.9 cm, with 24% located centrally and 19% ultracentrally. The typical SBRT regimen delivered a biologically effective dose (BED10) of 120 Gy. Over a median 19-month follow-up, 26% of treatments resulted in grade 2 or higher toxicity: 5% experienced grade 3 toxicity, and 0.1% (one patient) had grade 5 toxicity (death). Common toxicities included chest wall pain (11%), pneumonitis (9%), cough (2%), pleural effusion (1%), and hemoptysis (1%).<br /><br />Crucially, grade 3 pneumonitis rates varied by CTD type: 11% in patients with interstitial/idiopathic lung disease, compared to 2% in rheumatoid arthritis, and 0% in lupus or scleroderma. The fatal pneumonitis case was associated with interstitial lung disease. No central tumors caused grade 2 toxicity, though ultracentral tumors were linked to some grade 2 toxicities.<br /><br />The study concludes lung SBRT is generally safe for early-stage lung cancer patients with CTDs, showing no increased risk of severe toxicity compared to historical data. However, those with interstitial lung disease face elevated pneumonitis risk, consistent with recent prospective trials. Thus, lung SBRT remains an appropriate option for this population, with caution advised for patients with underlying interstitial lung disease.

Asset Subtitle

Gregory Videtic

Meta Tag

Speaker Gregory Videtic

Topic Early-Stage Non-small Cell Lung Cancer

Keywords

lung SBRT

connective tissue diseases

radiation toxicity

interstitial lung disease

rheumatoid arthritis

systemic lupus erythematosus

stereotactic body radiation therapy

pneumonitis risk

early-stage lung cancer

toxicity profile