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 struc tures. 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 grand malignanc ies, which are inoperable or not completely resected, and in recurrent dise ase. Modern techniques of conformal high LET radiotherapy, e.g. heavy ion b eam radiotherapy, will help to reduce the long and the short term toxicity of radiotherapy.