Monte Carlo (MC) simulation techniques are becoming very common in the Medical
Physicists community. MC can be used for modeling Single Photon Emission Computed
Tomography (SPECT) and for dosimetry calculations. 188Re, is a promising candidate for
radiotherapeutic production and understanding the mechanisms of the radioresponse of tumor
cells "in vitro" is of crucial importance as a first step before "in vivo" studies. The
dosimetry of 188Re, used to target different lines of cancer cells, has been evaluated by the
MC code GEANT4. The simulations estimate the average energy deposition/per event in the
biological samples. The development of prototypes for medical imaging, based on LaBr3:Ce
scintillation crystals coupled with a position sensitive photomultiplier, have been studied using
GEANT4 simulations. Having tested, in the simulation, surface treatments different from
the one applied to the crystal used in our experimental measurements, we found out that the
Energy Resolution (ER) and the Spatial Resolution (SR) could be improved, in principle, by
machining in a different way the lateral surfaces of the crystal. We have then studied a system
able to acquire both echographic and scintigraphic images to let the medical operator obtain
the complete anatomic and functional information for tumor diagnosis. The scintigraphic
part of the detector is simulated by GEANT4 and first attempts to reconstruct tomographic
images have been made using as method of reconstruction a back-projection standard algorithm. The proposed camera is based on slant collimators and LaBr3:Ce crystals. Within
the Field of View (FOV) of the camera, it possible to distinguish point sources located in air
at a distance of about 2 cm from each other. In particular conditions of uptake, tumor depth
and dimension, the preliminary results show that the Signal to Noise Ratio (SNR) values
obtained are higher than the standard detection limit.
| Identifer | oai:union.ndltd.org:unibo.it/oai:amsdottorato.cib.unibo.it:1583 |
| Date | 21 May 2009 |
| Creators | Lo Meo, Sergio <1970> |
| Contributors | Navarria, Francesco Luigi |
| Publisher | Alma Mater Studiorum - Università di Bologna |
| Source Sets | Università di Bologna |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, PeerReviewed |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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