title: Optimization technique for a Prompt Gamma-ray SPECT collimator system.
abstract: Because background radiation in an irradiation room creates a problem with the PG-SPECT (Prompt Gamma-ray Single Photon Emission Computed Tomography) system, which evaluates the absorbed dose for the Boron Neutron Capture Therapy treatment, optimization of a collimator system was performed while taking the shielding of background gamma-rays into consideration. Assuming that a parallel-beam collimator is used, three parameters--the diameter of a hole, the length of the collimator, and the number of detectors (the number of holes of the collimator)--were selected for optimization. Because the combinations of these parameters are limitless, it is difficult to determine them simultaneously. Therefore, a statistically derived Optimization Criterion has been proposed to optimize these parameters. When the spatial resolution was 1 cm-FWHM (full width at half maximum), the optimal diameter of the collimator was 5.4 mm, the optimal length was 321 mm, and the optimal number of detectors was 31 x 31.
authors.affiliation: Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan. masayori@hiroshima-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Ishikawa
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai
authors.forename: K
authors.initials: K
authors.lastname: Kanda
mesh_terms: D016754:Boron Neutron Capture Therapy / Q000295:instrumentation; D005720:Gamma Rays; D011874:Radiometry / Q000295:instrumentation*; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation*