Single Photon Emission Tomography Approach for Online Patient Dose Assessment in Boron Neutron Capture Therapy

D.M. MINSKY; A. VALDA; A. KREINER; A. A. BURLON

Buenos Aires, Argentina. Exposición oral y mural

Congreso; 12th International Congress of the International Radiation Protection Association; 2008

International Radiation Protection Association - Sociedad Argentina de Radiología

A tomographic imaging system for the measurement of the spatial distribution of the absorbed dose during a Boron Neutron Capture Therapy (BNCT) session is presented. The 10B(n,a)7Li boron neutron capture reaction produces a 478 keV gamma ray in 94% of the cases. Therefore its detection can serve as a basis for a non-invasive online absorbed dose determination since the dose absorbed by the tumor and healthy tissue strongly depends on the boron uptake and the neutron flux. For this purpose, a dedicated tomographic imaging system based on Single Photon Emission Computed Tomography is proposed. Monte Carlo numerical simulations are used for the system design aimed to have a spatial resolution of 1 cm. Prototypes based on CdZnTe semiconductor detectors and LaBr3(Ce) scintillators with optimized shielding were designed with Monte Carlo simulations. They were built and tested in reactor and accelerator based BNCT facilities. A projection of a phantom with two tumors with 400 ppm of 10B was successfully measured at the accelerator facility of the University of Birmingham.