Beam collimation and bolusing material optimizations for (10)boron neutroncapture enhancement of fast neutron (BNCEFN): Definition of the optimum irradiation technique
Jp. Pignol et al., Beam collimation and bolusing material optimizations for (10)boron neutroncapture enhancement of fast neutron (BNCEFN): Definition of the optimum irradiation technique, INT J RAD O, 43(5), 1999, pp. 1151-1159
Citations number
41
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging","Onconogenesis & Cancer Research
Journal title
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS
Purpose: In boron-10 neutron capture enhancement of fast neutron irradiatio
n (BNCEFN), the dose enhancement is correlated to the B-10 concentration an
d thermal neutron flux. A new irradiation technique is presented to optimiz
e the thermal neutron flux.
Methods and Materials: The coupled FLUKA and MCNP-4A Monte Carlo codes were
used to simulate the neutron production and transport for the Nice and Orl
eans facilities.
Results: The new irradiation technique consists of a 20-cm lead blocks addi
tional collimator, placed close to the patient's head, which is embedded in
a pure graphite cube, A 24-fold thermal neutron flux increase is calculate
d between a 5 x 5 cm(2) primary collimated field, with the patient's head i
n the air, and the same field size irradiated with the optimum irradiation
technique. This increase is more important for the p(60)+Be Nice beam than
for the p(34)+Be Orleans one. The thermal neutron Bur is 2.1 x 10(10) n(th)
/Gy for each facility. Assuming a 100 mu g/g B-10 concentration, a physical
dose enhancement of 22% is calculated. Moreover, the thermal neutron flux
becomes independent of the field size and the phantom head size,
Conclusion: This technique allows conformal irradiation of the tumor bed, w
hile the thermal neutron flux is enhanced, and spreads far around the tumor
. (C) 1999 Elsevier Science Inc.