<qa>  What is the name of the drug used in chemotherapy?RATIONALE: Pemetrexed disodium may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Drugs used in chemotherapy, such as carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Monoclonal antibodies, such as cetuximab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Cetuximab may also make tumor cells more sensitive to radiation therapy. Giving pemetrexed disodium, carboplatin, and radiation therapy together with cetuximab may kill more tumor cells. 