PET-guided Radiotherapy for Patients With Small Cell Lung Cancer.

This study is using PET scan imaging to guide radiation therapy decisions for people with limited-stage small cell lung cancer (a fast-growing type of lung cancer that has not spread beyond the chest). The goal is to tailor the radiation treatment plan based on what the PET scan reveals, potentially improving targeting and reducing unnecessary radiation to healthy tissue. **You may be eligible if...** - You have been diagnosed with small cell lung cancer confirmed by tissue biopsy - Your cancer is limited stage (contained within one side of the chest and lymph nodes, not spread widely) - Your general health is adequate (ECOG performance status of 0, 1, or 2) **You may NOT be eligible if...** - You have a different type of lung cancer (not small cell) - You have another concurrent cancer diagnosis - Your general health is very poor (ECOG 3 or worse) - Your cancer is extensive stage (spread beyond the chest to distant sites) Talk to your doctor to see if this trial is right for you.