title: Requirements for a Compton camera for in vivo range verification of proton therapy.
abstract: To ensure the optimal outcome of proton therapy, in vivo range verification is highly desired. Prompt γ-ray imaging (PGI) is a possible approach for in vivo range monitoring. For PGI, dedicated detection systems, e.g. Compton cameras, are currently under investigation. The presented paper deals with substantial requirements regarding hardware and software that a Compton camera used in clinical routine has to meet. By means of GEANT4 simulations, we investigate the load on the detectors and the percentage of background expected in a realistic irradiation and we simulate γ-ray detections subsequently used as input data for the reconstruction. By reconstructing events from simulated sources of well-defined geometry, we show that large-area detectors are favourable. We investigate reconstruction results in dependence of the number of events. Finally, an end-to-end test for a realistic patient scenario is presented: starting with a treatment plan, the γ-ray emissions are calculated, the detector response is modelled, and the image reconstruction is performed. By this, the complexity of the system is shown, and requirements and limitations regarding precision and costs are determined.
authors.affiliation: Now with: TU Wien, Atominstitut, Stadionallee 2, 1020 Vienna, Austria. Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstr. 400, 01328 Dresden, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Rohling
authors.forename: M
authors.initials: M
authors.lastname: Priegnitz
authors.forename: S
authors.initials: S
authors.lastname: Schoene
authors.forename: A
authors.initials: A
authors.lastname: Schumann
authors.forename: W
authors.initials: W
authors.lastname: Enghardt
authors.forename: F
authors.initials: F
authors.lastname: Hueso-González
authors.forename: G
authors.initials: G
authors.lastname: Pausch
authors.forename: F
authors.initials: F
authors.lastname: Fiedler
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D005720:Gamma Rays; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D009010:Monte Carlo Method; D061766:Proton Therapy / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods