Results of fast neutron therapy of adenoid cystic carcinoma of the salivary glands

Background. Adenoid cystic carcinomas (ACC) seem to have a better response to fast neutron irradiation than to photon beam therapy because of the high er relative biological effectiveness of neutron radiation. Methods. Between 1986 and 1995, 72 patients with ACC of the salivary glands were treated in Munster with fast neutrons. The median age was 54 years. All the patients had either recurrent or macroscopic rest tumor prior to neutron therapy. Th e median, total dose was 15.03 Gy. Median follow-up was 50 months. Results. 39.1% of the patients achieved a complete remission and 48.6% a partial re mission. The survival probability was 86% after one year, 73% after two yea rs and 53% after five years. The recurrence-free survival was 83% after one year, 71% after two years and 45% after five years. Conclusion. Neutron be am therapy seems to have been an effective treatment in these selected pati ents.