[French national evaluation for helicoidal tomotherapy: description of indications, dose constraints and set-up margins].

After a request for proposal initiated by National Institute against cancer (INCa) in 2005, three French centers in France started tomotherapy in the first semester of 2007. A national policy of evaluation was performed to study the feasibility of this innovative technique and to compare the interest of helicoidal tomotherapy with other modalities of conformal therapy. Common protocols have been designed to facilitate this evaluation. Description of dose, IMRT levels and constraints are achieved according to each selected indication as: sarcoma, head and neck tumors, lung cancer, mesothelioma, bone metastases, anal carcinoma and craniospinal irradiation.