title: Real-time detection of fast and thermal neutrons in radiotherapy with CMOS sensors.
abstract: The peripheral dose distribution is a growing concern for the improvement of new external radiation modalities. Secondary particles, especially photo-neutrons produced by the accelerator, irradiate the patient more than tens of centimeters away from the tumor volume. However the out-of-field dose is still not estimated accurately by the treatment planning softwares. This study demonstrates the possibility of using a specially designed CMOS sensor for fast and thermal neutron monitoring in radiotherapy. The 14 microns-thick sensitive layer and the integrated electronic chain of the CMOS are particularly suitable for real-time measurements in γ/n mixed fields. An experimental field size dependency of the fast neutron production rate, supported by Monte Carlo simulations and CR-39 data, has been observed. This dependency points out the potential benefits of a real-time monitoring of fast and thermal neutron during beam intensity modulated radiation therapies.
authors.affiliation: Université de Strasbourg, IPHC, 23 rue du Loess 67037 Strasbourg, France. CNRS, UMR7178, 67037 Strasbourg, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Arbor
authors.forename: Stephane
authors.initials: S
authors.lastname: Higueret
authors.forename: Halima
authors.initials: H
authors.lastname: Elazhar
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Combe
authors.forename: Philippe
authors.initials: P
authors.lastname: Meyer
authors.forename: Nicolas
authors.initials: N
authors.lastname: Dehaynin
authors.forename: Florence
authors.initials: F
authors.lastname: Taupin
authors.forename: Daniel
authors.initials: D
authors.lastname: Husson
mesh_terms: D005214:Fast Neutrons / Q000627:therapeutic use*; D005720:Gamma Rays / Q000627:therapeutic use; D009010:Monte Carlo Method; D011874:Radiometry / Q000295:instrumentation; D011878:Radiotherapy / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage