[Helical tomotherapy: description and clinical applications].

Helical tomotherapy is an innovative device combining with the same linac on board-imaging and IMRT facilities. The first national French evaluations, supported by National Institut of Cancer (INCa) are presented. Dosimetric characteristics as quality of homogeneity, cut-off outside target volumes allow IMRT treatments for large and complex volumes and a good organ at risk sparing. First comparative dosimetric studies are discussed.