Author/Editor		Maučec, Marko; Glumac, Bogdan; Rant, Jože; Krištof, Edvard
Title		Epithermal neutron beam for BNCT at the JSI TRIGA reactor - modelling and experimental verification
Translated title		Epitermični izvor nevtronov za terapijo raka z zajetjem nevtronov v boru na reaktorju TRIGA Instituta Jožef Stefan - modeliranje in eksperimentalna preveritev
Type		članek
Source		Radiol Oncol
Vol. and No.		Letnik 33, št. 1
Publication year		1999
Volume		str. 69-75
Language		eng
Abstract		It has been reported that satisfactory thermal/epithermal neutron beams for Boron lVeutron Ćapturc, Therapy (BNCT) could be designed at TRIGA research reactors, which are generally perceived as being safe to install and operate in populated areas. This contribution presents the most recent research activities in this field at the Jožef Stefan Institute TRIGA reactor, where an epithermal neutron beam for BNCT is being developed. Experimental verification of Monte Carlo simulation results proves the quality and wide applicability of the developed 3-D model, particularly of the reactor core and irradiation channels. Due to high attenuation of the epithermal neutron flux (fi epi = 4.1x106 n/cmZs, two orders of magnitude belozu the therapeutic limit) the irradiation facility in the current stage of development is not appropriate for the clinical BNCT treatments. Furthermore, the contribution of the 2.5 mm airgap surrounding the facility is unacceptably high, thus making the relative gamma dose (Dy/fiepi) almost 60-times higher than therapeutically rcc- ommended. Nevertheless, using gamma shielding of Pb or Bi and LiF or Li2C03 (thermal neutron cut-off, the quality of the epithermal neutron beam would be significantly upgraded and hecome appropriate fnr iii vitro studies of boron compound transport in malignant tumour cells or smaller lahoratory animals.
Summary		Zaradi specifičnih lastnosti obratovanja spadajo reaktorji TRIGA med najvarnejše raziskovalne reaktorje. V svetu se jih vedno več uporablja kot izvor termičnih oz. epitermičnih nevtronov v namene terapije raka z zajetjem nevtronov v boru (angl. Boron Neutron Ćapture Therapy). Prispevek prikazuje rezultate Monte Carlo modeliranja, optimizacije ter eksperimentalne verifikacije obsevalne naprave z epitermičnimi nevtroni razvite v radialnem kanalu reaktorja TRIGA na Institutu Jožef Stefan v Ljubljani. Rezultati potrjujejo široko uporabnost razvitega tri-dimenzionalnega modela reaktorja, predvsem sredice in obsevalnih kanalov. Zaradi visoke atenuacije nevtronskega fluksa (fiep = 4.1x106 n/cmZs, kar je dobra dva reda velikosti pod priporočeno terapevtsko mejo) obsevalna naprava v obstoječi izvedbi ni primerna za klinična BNCT obsevanja. Prispevek zračne reže, ki obdaja sistem filtrov dodatno prispeva k visoki specifični dozi gama žarkov in hitrih nevtronov na obsevalnem mestu, ki sta skoraj 60-krat višji od priporočenih vrednosti. Vendar pa bi z minimalno predelavo obsevalne naprave ter uporabo zaščitnega ohišja s Pb (ali Bi) ter LiF (ali Li2CO.3) lahko občutno izboljšali kvaliteto obsevalnega curka kot orodja za "in-vitro" študije transporta bora v malignih celičnih kulturah ali laboratorijskih živalih. *
Descriptors		BORON NEUTRON CAPTURE THERAPY NEOPLASMS NUCLEAR REACTORS MONTE CARLO METHOD