Boron concentration measurements by alpha spectrometry and quantitative neutron autoradiography in cells and tissues treated with different boronated formulations and administration protocols

The possibility to measure boron concentration with high precision in tissues that will be irradiated represents a fundamental step for a safe and effective BNCT treatment. In Pavia, two techniques have been used for this purpose, a quantitative method based on charged particles spectrometry and a boron biodistribution imaging based on neutron autoradiography. A quantitative method to determine boron concentration by neutron autoradiography has been recentlyset-up and calibrated for the measurement of biological samples, both solid and liquid, in the frame of the feasibility study of BNCT. Thist echnique was calibrated and the obtained results were cross checked with those of α spectrometry,inorderto validatethem. The comparisons were performed using tissues taken from animals treated with different boron administration protocols. Subsequently the quantitative neutron autoradiography was employed to measure osteosarcoma cell samples treated with BPA and with new boronated formulations

Gamma Residual Radioactivity Measurements on Rats and Mice Irradiated in the Thermal Column of a Triga Mark II Reactor for BNCT

The current Boron Neutron Capture Therapy (BNCT) experiments performed at the University of Pavia, Italy, are focusing on the in vivo irradiations of small animals (rats and mice) in order to evaluate the effectiveness of BNCT in the treatment of diffused lung tumors. After the irradiation, the animals are manipulated, which requires an evaluation of the residual radioactivity induced by neutron activation and the relative radiological risk assessment to guarantee the radiation protection of the workers. The induced activity in the irradiated animals was measured by high-resolution open geometry gamma spectroscopy and compared with values obtained by Monte Carlo simulation. After an irradiation time of 15 min in a position where the in-air thermal flux is about 1.2 x 10(10) cm(-2) s(-1), the specific activity induced in the body of the animal is mainly due to Na-24, Cl-38, K-42, Mn-56, Mg-27 and Ca-49; it is approximately 540 Bq g(-1) in the rat and around 2,050 Bq g(-1) in the mouse. During the irradiation, the animal body (except the lung region) is housed in a 95% enriched Li-6 shield; the primary radioisotopes produced inside the shield by the neutron irradiation are H-3 by the Li-6 capture reaction and F-18 by the reaction sequence Li-6(n,alpha)H-3 -> O-16(t,n)F-18. The specific activities of these products are 3.3 kBq g(-1) and 880 Bq g(-1), respectivel