Salivary gland-sparing helical tomotherapy for head and neck cancer: Preserved salivary function on quantitative salivary gland scintigraphy after tomotherapy.

GOALS: Prospective evaluation of salivary gland preservation, overall survival and local recurrence-free survival after head and neck cancer treated by helical tomotherapy (HT). MATERIAL AND METHODS: From March 2007 to February 2009, 30 patients with head and neck cancer were treated by HT. The salivary excretion fraction (SEF) was assessed by technetium salivary gland scintigraphy before, and 6, 12 and 18 months after HT to define salivary gland preservation rates. Patients were reviewed every 3 months to assess clinical toxicity. RESULTS: The median follow-up was 4.3 years. The mean dose to the ipsilateral parotid gland (IPG) was 25.4Gy. Good preservation of parotid gland function was observed in 84% of the 19 patients evaluated by scintigraphy at 18 months. The 5-year local recurrence-free survival (LRFS) was 100% among the 6 patients who received a dose of more than 26Gy to the parotid gland. The 28-month LRFS was 33% in the group that received a dose of less than 20Gy versus 91% in the group that received a dose of more than 20Gy to the IPG. CONCLUSIONS: Helical tomotherapy reduced the incidence and severity of xerostomia. A mean dose to the parotid between 20 and 26Gy allowed preservation of salivary function without compromising treatment efficacy. However, parotid-sparing HT requiring a mean dose less than 20Gy is associated with an increased risk of recurrence.