Gadolinium neutron capture in glioblastoma multiforme cells

Purpose: A proof of principle for cell killing by Gadolinium (Gd) neutron capture in Magnevist (R) preloaded Glioblastoma multiforme (GBM) cells is provided. Materials and methods: U87cells were pre-loaded with 5 mg/ml Magnevist (R) (Gd containing compound) and irradiated using an enhanced neutron beam developed at NIU Institute for Neutron Therapy at Fermilab. These experiments were possible because of an enhanced fast neutron therapy assembly designed to use the fast neutron beam at Fermilab to deliver a neutron beam containing a greater fraction of thermal neutrons and because of the development of improved calculations for dose for the enhanced neutron beam. Clonogenic response was determined. Results: U87 cell survival after gamma irradiation, fast neutron irradiation and irradiation with the enhanced neutron beam in the presence or absence of Magnevist (R) were determined. Conclusions: U87 cells were the least sensitive to gamma radiation, and increasingly sensitive to fast neutron irradiation, irradiation with the enhanced neutron beam and finally a significant enhancement in cell killing was observed for U87 cells preloaded with Magnevist (R). The sensitivity of U87 cells pre-loaded with Magnevist (R) and then irradiated with the enhanced neutron beam can at least in part be attributed to the Auger electrons emitted by the neutron capture event.