CT-based parotid gland location: implications for preservation of parotid function

Purpose: The position of the parotid gland in relation to surrounding struc tures was investigated. Materials and methods: Sixty-five patients with head and neck tumours were prospectively evaluated. Parotid position was determined using beam's eye v iews of CT images projected on simulator films. Distances between the diffe rent borders of the parotid gland and surrounding bony marks were quantitat ively assessed. Results: The parotid gland volume ranged from 12.9 to 46.4 cm(3). The dista nce between the cranial border of the parotid gland and the tuberculum ante rior of the atlas ranged between 0.7 and 4.8 cm. The position of the paroti d gland was unaffected by the angle of the mandible. Conclusions: The size and position of the parotid gland varies largely amon g patients. As the extent of radiation-induced salivary dysfunction depends on the volume of the gland tissue exposed, CT-based simulation of radiatio n fields is necessary. (C) 2000 Elsevier Science Ireland Ltd. All rights re served.