MRI and CT Simulation in the Evaluation of Tumor Response and Target Volume Definition for Esophageal or Esophagogastric Cancer Patients Undergoing Chemoradiotherapy

This study is using MRI and CT scans taken at different points during chemoradiation therapy (a combination of chemotherapy and radiation) to track how esophageal (food pipe) or stomach-junction cancers respond to treatment, and to plan radiation more accurately. **You may be eligible if...** - You have been diagnosed with squamous cell or adenocarcinoma of the esophagus or where the esophagus meets the stomach - Your tumor cannot be removed by surgery, or surgery may be possible after treatment - Your cancer is at a locally advanced stage (no spread to distant organs except possibly neck lymph nodes) - You are over 18 years of age - You have not had previous chest radiation or chemotherapy - Your blood, liver, and kidney function are within acceptable levels **You may NOT be eligible if...** - Your cancer has spread to distant organs - You have had prior chemotherapy or radiation to the chest - Your organ function is too poor to safely receive chemoradiation Talk to your doctor to see if this trial is right for you.