Radiotherapy to Patients With CA19-9-elevated Advanced Pancreatic Cancer

This study tests whether adding radiotherapy to ongoing chemotherapy helps people with locally advanced pancreatic cancer whose tumor marker (CA19-9) was elevated at diagnosis but dropped to normal levels after chemotherapy. Normal CA19-9 after treatment may indicate a good response, and adding radiation at this point might further improve outcomes. **You may be eligible if...** - You are between 18 and 80 years old - You have confirmed advanced pancreatic cancer that is locally advanced (has not spread to distant organs) - Your CA19-9 was high at diagnosis but has dropped to normal (≤37 U/mL) after chemotherapy - You have not previously had radiotherapy - Your cancer can be measured on scans - You are in reasonably good physical condition **You may NOT be eligible if...** - Your cancer has spread to distant organs (metastatic) - Your CA19-9 did not normalize with chemotherapy - You have had prior radiotherapy - You have not yet tried chemotherapy Talk to your doctor to see if this trial is right for you.