* Ultimately we plan to find the maximum tolerated dose of the combination of gemcitabine, 5-fluorouracil and radiation therapy. We also hope to assess the number of people who respond to this therapy and to assess the feasibility of giving intraoperative radiation therapy following gemcitabine, 5-fluorouracil, and external beam radiation therapy.
* A surgical procedure, either laparotomy or laparoscopy, will be required to check the amount of disease before treatment is started.
* All patients will receive the same two chemotherapy drugs and radiation therapy. Both gemcitabine and 5-fluorouracil will begin on the first week of radiation therapy. 5-fluorouracil will be given continuously by intravenous infusion and will continue until the external beam radiation therapy is completed. The gemcitabine will be given (at different doses for each cohort of patients) once per week for seven weeks. Radiation therapy will be given daily for five days for seven weeks. On those days when gemcitabine is given, radiation therapy will be given approximately four hours after the gemcitabine dose.
* Four weeks after completing the radiation therapy and chemotherapy, patients will undergo a scan to check the extent of disease. Following the scan, patients will be considered for a repeat surgical procedure to remove the tumor, if possible. If removal of the tumor is not possible, patients will receive intraoperative radiation therapy.
* After completing the therapy, patients will be seen at least every 3 months for one year. A complete physical exam and CT scan will be done regularly.