Photon irradiation of unresectable carcinomas of salivary glands.

This paper presents our experience and the local control rates of a group of patients with inoperable and unresectable lesions treated by photon irradiation from 1980 through 1989. The patient material consists of a total of 24 patients, 9 with carcinoma arising from the parotid gland and 15 with lesions in the minor salivary glands, mainly the oral cavity and oropharynx. The pathologic slides were reviewed and malignancy of various cell types confirmed. The 5-year actuarial local control of parotid gland lesions after photon irradiation was 100% and the survival rate was 65%. For the minor salivary gland lesions, the 5-year actuarial local control was 78% and the survival rate with or without disease was 93%. All lesions were irradiated by accelerated hyperfractionated photons (bid) with 1.6 Gy per fraction, intermixed with various boost techniques including electron beam, intraoral cone, interstitial implant, and/or submental photons for a total of 65-70 Gy. Most treatment failures of parotid cancer were due to distant metastases. The present series showed excellent local control and satisfactory survival of inoperable and unresectable salivary gland carcinomas after state-of-the-art photon irradiation, comparable to that achieved by neutron irradiation. The late complications were minimal. A controlled randomized trial may be indicated.