The role of high-LET radiotherapy compared to conformal photon radiotherapy in adenoid cystic carcinoma.

Tumors of the base of skull represent a challenging radiooncological target due to their close proximity to dose limiting critical normal tissue structures. A critical review of the literature provides evidence that high-LET radiotherapy offers a therapeutic gain factor compared to low-LET radiation and should be the treatment of choice in advanced salivary gland malignancies, which are inoperable or not completely resected, and in recurrent disease. Modern techniques of conformal high LET radiotherapy, e.g. heavy ion beam radiotherapy, will help to reduce the long and the short term toxicity of radiotherapy.