OUTLINE: This is a randomized, double blind, parallel, multicenter study. Patients are randomized to one of three treatment arms. Arm I: Patients receive oral lerisetron with an oral placebo once daily for 14 days. Arm II: Patients receive oral lerisetron once daily for 14 days. Arm III: Patients receive oral granisetron hydrochloride once daily for 14 days. At 1-2 hours following antiemetics, all patients undergo concurrent daily radiotherapy for at least 10 out of 14 days. Patients are followed daily for 10 days.