The dose to deliver is 6.0 Gy per fraction, two treatment days per week (preferably Monday and Thursday or Tuesday and Friday) to a total of 30.0 Gy in five fractions in 2 1/2 weeks.

Photon energies of 1.25 to 6 MeV or electron energies from 6-15 MeV are allowed. Treatment should be given with electrons whenever feasible. The electron energy should be appropriate for the depth of the tumor and surgical bed, e.g., 6-9 MeV for primary tumor bed, 12-15 MeV for parotid and upper neck nodes, and 9 MeV for mid- and lower jugular and supraclavicular nodes. Photons may be used in selected cases, e.g., opposed AP-PA fields to encompass subdigastric, mid and lower jugular and supraclavicular nodes when the primary lesion is situated at the lateral aspect of the mid-portion of the neck with positive mid-jugular nodes.

Target Volume

Fields must include the primary tumor bed (except for instances of an unknown primary or for primary lesions excised >= 1 yr) and ipsilateral neck nodes down to the clavicle. The target volume thus includes parotid nodes for lesions of frontal, preauricular, temporal areas, auricle, and cheek and suboccipital nodes for lesions situated behind the mastoid.

Fields borders encompass nodal areas and tumor bed with at least 2 cm margins for lesions of 1.5 - 4.0 mm, or 3 cm margins for thicker lesions. Bolus should be used to prevent underdosage to tumor bed when electrons of <= 9 MeV are used. When it is necessary to irradiate parotid lymph nodes, it is recommended to use a lead alloy-containing intraoral stents to limit the dose delivered to the tongue and oral tissues.

The vast majority of target volumes can be encompassed with two abutting electron fields. Intraparotid and upper neck nodes are encompassed in one field that is similar to that used for treating primary tumors of the parotid gland. This field also covers most primary tumor beds of lesions arising at preauricular, lower temporal areas, auricle, and cheek. The mid and lower neck nodes are encompassed in an adjoining appositional field. If the site of the primary lesion is outside the boundary of the "parotid" field, a third adjoining field is added to irradiate the tumor bed. The junction between the abutting fields is moved 1 cm after the 2nd and 4th treatments to prevent dose inhomogeneity and thus minimize the risk of fibrosis. Document junction changes in treatment chart.

Electron Beam: The protocol dose shall be prescribed at the depth of maximum dose. The energy and field size shall be chosen so that the target volume is encompassed within 90% of the prescribed dose.

The maximum permissible dose to the spinal cord is 24 Gy.