Feasibility study on the use of SPECT for boron dose imaging in TRR based BNCT

Boron Neutron Capture Therapy (BNCT) is one of the promising treatment methods for some malignant tumors such as Glioblastoma Multiforme (GBM). One of the requirements of BNCT treatment is the accurate and real-time boron-concentration monitoring to ensure the efficacy of treatment and no leakage of boron. An accurate method for real-time calculation of the boron dose distribution mapping during irradiation is Single Photon Emission Computed Tomography (SPECT), in which the determination of boron distribution is based on the detection of 478 keV prompt gamma-rays generated through thermal neutron capturing by B-10. Tehran Research Reactor (TRR) is the only possible source for BNCT in Iran, so as the first approach, this BNCT-SPECT system has been evaluated for TRR. In this paper, an imaging system of BNCT-SPECT including four arrays of collimator/detector has been designed for real-time dosimetry as well as B-10 concentration distribution map in the phantom that placed in front of the therapeutic neutron beam using the Monte Carlo simulation code MCNP6. Maximum Likelihood Expectation Maximization (MLEM) method has been used for image reconstruction which results 1 cm spatial resolution.