<qa>  What is the standard of care for patients with benzydamine hydrochlorideThis is a multicenter, double-blind, randomized, vehicle-controlled study including an open-label standard of care arm, to determine the effectiveness and safety of benezydamine hydrochloride 0.15 oral rinse as compared with vehicle oral rinse, and vehicle oral rinse as compared to the care normally used in the treatment of radiation-induced oral mucositis. The hypotheses are that benzydamine hydrochloride 0.15 oral rinse is better than vehicle oral rinse as measured by the proportion of patients reaching a WHO mucositis score of 3 by 5500 cGy and vehicle is no worse than the standard of care as measured by the proportion of patients reaching a WHO mucositis score of 3 by 5500 cGy. Patients receiving benzydamine hydrochloride 0.15 or vehicle double-blind oral rinses will place 15 mL in the mouth for 2 minutes, gargling for a few seconds at the beginning and end of the rinse, and then expectorate the entire dose. Dosing with oral rinses will be every 2 - 3 hours while awake for a minimum of 4 times daily to a maximum of 8 times per day. Double-blind oral rinses will continue daily throughout the duration of the subjects radiation treatment regimen plus 2 additional weeks 