If you are found to be eligible to take part in this study, you will receive radiation therapy 1 time a day, for 5 days in a row (Monday-Friday) for 6 -7 weeks (30-35 treatments in all). You will take the chemotherapy drug, capecitabine, by mouth 2 times a day, at morning and night, on each of the days that you receive radiation therapy. These pills will not be taken on Saturday or Sunday. These pills should be taken within 30 minutes of eating and with a full glass of water.