Combined use of FLUKA and MCNP-4A for the Monte Carlo simulation of the dosimetry of 10B neutron capture enhancement of fast neutron irradiations.

Boron neutron capture enhancement (BNCE) of the fast neutron irradiations use thermal neutrons produced in depth of the tissues to generate neutron capture reactions on 10B within tumor cells. The dose enhancement is correlated to the 10B 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 6Li or 7Li). The theoretical results were in good agreement with the experimental results: the thermal neutron flux was calculated at 10.3 X 10(6) n/cm2 s1 and measured at 9.42 X 10(6) n/cm2 s1 at 4 cm depth of the phantom and with a 10 cm X 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 X 10 cm or 20 cm X 20 cm fields, provided that 100 micrograms/g of 10B 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.

[1]  O. Harling,et al.  Monte Carlo-based treatment planning for boron neutron capture therapy using custom designed models automatically generated from CT data. , 1996, International journal of radiation oncology, biology, physics.

[2]  H. B. Liu.  PbF2 compared to Al2O3 and AlF3 to produce an epithermal neutron beam for radiotherapy. , 1996, Medical physics.

[3]  F. Demard,et al.  Boron neutron capture irradiation: setting up a clinical programme in Nice. , 1996, Bulletin du cancer. Radiotherapie : journal de la Societe francaise du cancer : organe de la societe francaise de radiotherapie oncologique.

[4]  D. Allen,et al.  A design study for an accelerator-based epithermal neutron beam for BNCT. , 1995, Physics in medicine and biology.

[5]  P. Chauvel,et al.  Irradiations par capture de neutrons: principe, résultats actuels et perspectives , 1995 .

[6]  H. B. Liu,et al.  Design of a high-flux epithermal neutron beam using 235U fission plates at the Brookhaven Medical Research Reactor. , 1994, Medical physics.

[7]  T. Buchholz,et al.  Boron neutron capture therapy: a mechanism for achieving a concomitant tumor boost in fast neutron radiotherapy. , 1994, International journal of radiation oncology, biology, physics.

[8]  T. Buchholz,et al.  Enhancement of fast neutron beams with boron neutron capture therapy. A mechanism for achieving a selective, concomitant tumor boost. , 1994, Acta oncologica.

[9]  E. Grusell,et al.  Dose enhancement in fast neutron tumour therapy due to neutron captures in 10B. , 1994, Acta oncologica.

[10]  W. Sauerwein,et al.  Monte Carlo calculation of dose enhancement by neutron capture of 10B in fast neutron therapy. , 1993, Physics in medicine and biology.

[11]  B. Mijnheer,et al.  An investigation of the possibilities of BNCT treatment planning with the Monte Carlo method. , 1993, Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al].

[12]  A. Soloway,et al.  Boron neutron capture therapy for cancer. Realities and prospects , 1992 .

[13]  F. D. Brooks,et al.  Neutron fluence and kerma spectra of a p(66)/Be(40) clinical source. , 1992, Medical physics.

[14]  R. Shefer,et al.  Accelerator-based epithermal neutron beam design for neutron capture therapy. , 1992, Medical physics.

[15]  P. Andreo.  Monte Carlo techniques in medical radiation physics. , 1991, Physics in medicine and biology.

[16]  W. Sauerwein,et al.  Dosimetry and fluence measurements with a new irradiation arrangement for neutron capture therapy of tumours in mice. , 1991, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[17]  G. Brownell,et al.  A Monte Carlo investigation of the dosimetric properties of monoenergetic neutron beams for neutron capture therapy. , 1991, Radiation research.

[18]  E. Grusell,et al.  The production by 72 MeV protons of keV neutrons for 10B neutron capture therapy. , 1989, Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al].

[19]  H. Sack,et al.  Neutron capture therapy using a fast neutron beam: clinical considerations and physical aspects. , 1989, Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al].

[20]  C. K. Wang,et al.  A neutronic study of an accelerator-based neutron irradiation facility for boron neutron capture therapy , 1989 .

[21]  V. Bond,et al.  Current status of 10B-neutron capture therapy: enhancement of tumor dose via beam filtration and dose rate, and the effects of these parameters on minimum boron content: a theoretical evaluation. , 1985, International journal of radiation oncology, biology, physics.