Omitting CTV for Primary Tumor in LS-SCLC

This study is testing a modified radiation therapy approach for limited-stage small-cell lung cancer (SCLC) that omits a traditional safety margin (called the CTV) around the primary tumor. Researchers want to determine if this more targeted approach is just as effective while reducing side effects. **You may be eligible if...** - You are between 18 and 75 years old with a confirmed SCLC diagnosis - Your cancer is limited-stage (has not spread widely beyond the chest) - You are in good physical condition (KPS ≥ 80) with less than 10% weight loss in the past 6 months - Your cancer has not progressed after 2–4 cycles of standard chemotherapy (etoposide/carboplatin or etoposide/cisplatin) - Your blood counts and organ function meet required levels **You may NOT be eligible if...** - You have another cancer (unless it has been cured for at least 5 years) - You have uncontrolled heart disease or had a heart attack in the past 6 months - You have a history of serious psychiatric illness - You are pregnant or breastfeeding - You have poorly controlled diabetes or high blood pressure - You have lung inflammation (interstitial pneumonia) or active infection Talk to your doctor to see if this trial is right for you.