DIADOMI

In the eyes of statistics: 2 800 000 new sickness events and 1 700 000 death per year in Europe, cancer is one of the main public health concern, and is the main death cause in France. At the present time radiotherapy, used all alone or combined with other treatments, is the heart of cancer treatment. Innovative technologies using small fields are currently used in cancer treatment occurring in sensitive area. The clinical efficiency of these techniques have been proved but critical risks due to non well known beam characteristics curb the use of such techniques. For example, the measurement of absolute dose is not possible actually due to the lake of suited detectors to these measurements. The aim of this project is to develop a diamond specific detector for accurate absolute dose measurement during treatment using small fields. This work will lead to a very small size (with an active area <1mm3), high sensitivity (signal to noise ratio~1000) and tissue equivalence (diamond atomic number: Z=6, packaging is water equivalent) device. Precise specifications will permit to reveal technological and clinical constraints associated to the dosimeter after that, the dosimeter will be scaled, optimized and realized. Clinical environment and standard tests will allow us to probe the diamond detector response in standard and small fields irradiation tests. To improve dose measurements accuracy in every particular point of the volume and for every treatment, Monte-Carlo simulation tools will complete small fields diamond detector measurements and hospital ordinary dosimeters measurements. This project is based on partner assessments: • CEA-LIST on built-in, simulation and characterization of the dosimeter in standard conditions • IRSN on medical dosimeters in particular its know-how concerning the use of dosimeters in small field dosimetry • Hospitals to perform measurements in clinical environment and to set specifications: Pitié Salpêtrière (APHP - Paris) hospital academic centre, Alexis Vautrin (Nancy), René Gauducheau and Léon Bérard (Lyon) cancer centres. • In final part, BESTEK PLASSYS will perform a detector pre-industrialization. These ones will benefit from improvements gained during clinical testing.