The implications of improved treatment of malignant salivary gland tumors by fast neutron radiotherapy.

The conventional treatment for cancer of the salivary glands is surgery, with or without X ray therapy. In advanced tumors (Stage III and IV), local control and 5-year survival rates are less than 35%. Radical surgery severs the facial nerve in the majority of operations on parotid gland tumors. Local control of unresectable salivary gland tumors was achieved, in 74% of cases, by fast neutron therapy. From the MRC cyclotron at Hammersmith Hospital neutrons were given to 65 patients, with locally advanced or recurrent tumors, 89% of which were Stage IV. Local control and 5-year survival rates were 72% and 50%, respectively. The facial nerve was not damaged by neutron therapy. In patients with parotid gland tumors, 77% regained or maintained function. Function was lost in 14% through recurrence and 9% remained paralyzed. The results were achieved using beams from primitive machines with serious disadvantages. The results from neutrons implicate improvements for locally advanced tumors of non-epidermal origin in other sites of the body, especially with the high energy neutrons now available from modern cyclotrons.