PhI Study of Erbitux & Gemcitabine w/Radiation Therapy for Locally Adv. Pancreas Ca

RATIONALE: Drugs used in chemotherapy, such as gemcitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as cetuximab, can block tumor growth in different ways. Some find tumor cells and help kill them or carry tumor-killing substances to them. Others interfere with the ability of tumor cells to grow and spread. Cetuximab may also stop the growth of tumor cells by blocking blood flow to the tumor. Radiation therapy uses high-energy x-rays to kill tumor cells. Gemcitabine and cetuximab may make tumor cells more sensitive to radiation therapy. Giving gemcitabine together with cetuximab and radiation therapy may kill more tumor cells. PURPOSE: This phase I trial is studying the side effects and best dose of gemcitabine when given together with cetuximab and radiation therapy in treating patients with locally advanced pancreatic cancer that cannot be removed by surgery.