Combined use of FLUKA and MCNP-4A for the Monte Carlo simulation of the dosimetry of 10B neutron capture enhancement of fast neutron irradiations
| Autor: | G. Fares, Nicole Brassart, Pascal Cuendet, Florence Colomb, Gilles Prevot, Jean-Philippe Pignol, Ahmed Hachem, R. Sabattier, Cheikh M’Bake Diop |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Bonner sphere
Physics Neutron transport Phantoms Imaging business.industry Radiotherapy Planning Computer-Assisted Neutron stimulated emission computed tomography Monte Carlo method Biophysics Boron Neutron Capture Therapy General Medicine Biophysical Phenomena Neutron temperature Fast Neutrons Nuclear physics Neutron capture Neoplasms Humans Dosimetry Thermoluminescent Dosimetry Neutron Nuclear medicine business Monte Carlo Method Technology Radiologic |
| Zdroj: | Medical Physics. 25:885-891 |
| ISSN: | 0094-2405 |
| Popis: | Boronneutron capture enhancement (BNCE) of the fast neutron irradiations use thermal neutrons produced in depth of the tissues to generate neutron capture reactions on 10 B within tumor cells. The dose enhancement is correlated to the 10 B concentration and to thermal neutron flux measured in the depth of the tissues, and in this paper we demonstrate the feasibility of Monte Carlo simulation to study the dosimetry of BNCE. The charged particle FLUKA code has been used to calculate the primary neutron yield from the beryllium target, while MCNP-4A has been used for the transport of these neutrons in the geometry of the Biomedical Cyclotron of Nice. The fast neutron spectrum and dose deposition, the thermal flux and thermal neutron spectrum in depth of a Plexiglas phantom has been calculated. The thermal neutron flux has been compared with experimental results determined with calibrated thermoluminescent dosimeters (TLD-600 and TLD-700, respectively, doped with 6 Li or 7 Li ). The theoretical results were in good agreement with the experimental results: the thermal neutron flux was calculated at 10.3×10 6 n/cm 2 s 1 and measured at 9.42×10 6 n/cm 2 s 1 at 4 cm depth of the phantom and with a 10 cm×10 cm irradiation field. For fast neutron dose deposition the calculated and experimental curves have the same slope but different shape: only the experimental curve shows a maximum at 2.27 cm depth corresponding to the build-up. The difference is due to the Monte Carlo simulation which does not follow the secondary particles. Finally, a dose enhancement of, respectively, 4.6% and 10.4% are found for 10 cm×10 cm or 20 cm×20 cm fields, provided that 100 μg/g of 10 B is loaded in the tissues. It is anticipated that this calculation method may be used to improve BNCE of fast neutron irradiations through collimation modifications. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text