5. Strategy for MRI-guided BNCT

Author: Martin Kellert and Evamarie Hey-Hawkins

Gadolinium has attracted attention not only as an MRI contrast agent , but also as an alternative NCT agent due to the high neutron capture cross section of the 157Gd isotope (~255,000 barn), which is around 66 times larger compared to that of 10B (~3800 barn). Thus, a combination of MRI and BNCT seems possible (MRI-guided BNCT). C-[N-(DOTAMA-C6)-carbamoylmethyl]-C′-palmitamidomethyl-o-carborane (1) was synthesized as dual boron/Gd amphiphile. Micelles were prepared by mixing with low density lipoproteins (LDL) , which are natural nanoparticles devoted to the transport of fats within the body through the blood stream. Delivery to mesothelioma cells was achieved with a therapeutic dose of boron (26 ppm). Tumor growth in treated mice showed a drastic reduction of about 80–85% 40 days after neutron irradiation.

Fig. 5 Molecular structure of the dual boron/Gd amphiphile 1