Concurrent Chemoradiation + 5-FU + Mitomycin-C in Anal Carcinoma

This research study is a Pilot Study. Pilot studies are conducted to see if it is practical to do this type of research ona larger scale in the future. The pilot part of the study is to assess the possibility of using pencil beam proton radiation to treat your type of cancer. Proton radiation is used for many other types of malignancies, but its use for the treatment of anal cancer has been limited. The treatment is still being studied as research doctors are trying to find out more about its use in the treatment of anal cancer. Proton beam radiation therapy is an FDA approved radiation delivery system. You are being asked to participate in this study because you have cancer in the anal canal. Conventional radiation therapy with photons in combination with 5-FU and mitomycin-C is used as standard treatment for many patients with anal cancer. In this research study we are looking at another type of radiation called proton radiation, which is known to spare surrounding tissue and organs from radiation. Proton radiation delivers radiation to the area requiring radiation but delivers no dose beyond the region requiring treatment. There are several techniques that can be used to deliver proton radiation therapy. One of the newer techniques, called pencil beam scanning, allows for more accurate delivery of radiation to your tumor and further reduces the amount of normal tissue exposed to radiation. Most proton patients are treated with a number of beams that study doctors conform to the shape of your tumor. Pencil beam scanning delivers radiation with a single, narrow proton beam that is swept over the area of your tumor. This may reduce side effects that patients would normally experience with conventional radiation therapy or other means of delivering proton radiation therapy, and also minimizes treatment time. In this research study, we are evaluating the effectiveness of using pencil beam proton radiation delivered to reduce side effects associated with radiation t