Before entering this study the doctor will examine the patient and order blood tests. These tests will use approximately 10 ml of blood. Blood work should be done within 3 weeks prior to treatment.. Women of child-bearing potential are required to have a pregnancy test done within 7 days prior to the start of treatment . A CT or a PET/CT scan of the chest, abdomen and pelvis will be done within 4 weeks prior to starting treatment . All subjects participating in this study will receive radiation therapy and chemotherapy. Patients will get 4 cycles of chemotherapy along with radiation. Each cycle of chemotherapy consists of gemcitabine given i.v. on day 1 and day 8 of treatment. XRT is given on days 1 and 2 and on days 8 and 9 twice a day. This works out to 8 treatments of XRT per course of chemo. Overall, a total of 32 treatments of radiation therapy will be given during the 4 sessions of chemotherapy. Blood work for CBC with differential and platelets will be done prior to each dose of chemotherapy.The investigational portion of this study is the radiation therapy given to the abdomen on the same day and the day after the patient receives chemotherapy. Three-Four weeks after treatment completion the patient will be evaluated again. The treating physician will examine the patient and order blood tests. These tests will use approximately 10 ml of blood. The physician will also order a repeat CT or PET/CT to compare the disease status after treatment. These tests are not experimental and are part of routine check-ups of patients with pancreatic cancer. Patients will be followed for survival. Protected health information will not be reviewed by someone other than the patient's provider to identify potential subjects.