Background Information Radiation therapy is used in a definitive manner or as an adjunct to surgery in most of the head and neck cancer patients which inevitably lead to xerostomia (salivary gland dysfunction) in almost all patients. Xerostomia is debilitating condition which adversely affects the deglutition, mastication, gustation, speech and lead to increased susceptibility of structures in mouth to infection. Xerostomia may also interfere with nutrition and sleep of patient and thereby has a significant negative impact on patient's quality of life. Various modalities have been explored to prevent or decrease the incidence of xerostomia and the most successful methods are; use of Intensity modulated radiotherapy (IMRT) to spare the parotid salivary gland from radiation, Sparing submandibular salivary gland from radiation by it's transfer to sub mental space, use of Amifostine to protect salivary glands from radiation and use of cholinergic agonists like pilocarpine to stimulate salivary secretion. Both amifostine and pilocarpine are associated with significant side effects and amifostine is too costly to be used in routine practice. At our center, we were successful in decreasing the incidence of xerostomia significantly by using either IMRT sparing parotid gland (Parliament et al 2004) or submandibular gland transfer (SGT) sparing submandibular gland (Jha et al 2003)without compromising the tumor control rates. Both these modalities were not associated with any added toxicity which makes these methods superior to pilocarpine and amifostine. To improve upon our results by sparing both the major salivary glands, we plan to explore a combined approach of IMRT and SGT in head and neck cancer patients after surgery. For IMRT we had used "step-and-shoot" technique on a Varian 2300 EX linac with 120-leaf Millenium MLC. Since December 2002, the Cross Cancer Institute has had a helical tomotherapy unit at its disposal for IMRT and a planning study (van Vulpen et al 2005) conducted comparing the step-and-shoot IMRT and Helical tomotherapy for 5 oropharynx patients showed that tomotherapy plans compared favorably with step- and-shoot plans regarding sparing of the parotid glands. Hence we intend to use helical tomotherapy as an IMRT tool for this study.