 RATIONALE: Radiation therapy uses high-energy x-rays to kill tumor cells. Drugs used in chemotherapy, such as docetaxel, fluorouracil, and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving radiation therapy together with chemotherapy may kill more tumor cells. It is not yet known whether radiation therapy, docetaxel, and fluorouracil are more effective than radiation therapy, docetaxel, and cisplatin as first-line therapy in treating pancreatic cancer. 