en Radiation Biology Radiation Biology تحقيق بديع Original Research <p><strong>Background:</strong> The aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or PMMA), A150 plastic and TE- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. <strong> Materials and Methods:</strong> Thermal neutron fluence, photon dose and epithermal neutron dose distributions were computed for the epithermal neutron beam of the optimized linac based BNCT. <strong>Results:</strong> Amongst all investigated phantom materials, TE-liquid was shown to be a better substitute for brain tissue than other phantom materials. The differences between TE- liquid and brain at the depth of 6.1 cm for thermal neutron fluence, gamma dose and epithermal neutron dose distributions was calculated 2.80%, 2.40% and -13.87% , respectively. In comparison with the other gel dosimeters, LMD2 provided a better simulation of radiation transport in the brain. It&#39;s results differed from the real brain, at the depth of 6.1 cm, for thermal neutron fluence, gamma dose and epithermal neutron dose distributions, by -1.27%, 4.20% and 21.05% respectively. <strong>Conclusion:</strong> Even though, in gamma dose distribution the LMD2 has large deviation from brain tissue distribution, the deviation is approximately independent of depth, so the results can be multiplied by a constant coefficient to be more consistent with reality. Even though, TE- liquid showed satisfactory results for brain tissue substitution in BNCT, but some properties of gel dosimeters such as three dimensionality, make LMD2 a potentially good dosimeter for dosimetric verification in BNCT.</p> Gel dosimetry, BNCT, phantom, MCNP, dose distribution 139 149 http://ijrr.com/browse.php?a_code=A-10-1-499&slc_lang=en&sid=1 S.M. Abtahi sm_abtahi@sbu.ac.ir 790031947532846007595 790031947532846007595 Yes University of Shahid Beheshti, Radiation Medicine Department, P. O. Box 19839- 63113, Tehran, Iran S.M.R. Aghamiri 790031947532846007596 790031947532846007596 No University of Shahid Beheshti, Radiation Medicine Department, P. O. Box 19839- 63113, Tehran, Iran H Khalafi 790031947532846007597 790031947532846007597 No Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran F. Rahmani 790031947532846007598 790031947532846007598 No University of Shahid Beheshti, Radiation Medicine Department, P. O. Box 19839- 63113, Tehran, Iran