Study of the Spheronization Process of Glass Particles for Internal Selective Radiotherapy Application

Abstract

The selective internal radiotherapy is an alternative to treat hepatocellular carcinoma. Glass microspheres containing a β-emitter radionuclide are introduced in the liver, and they concentrate preferentially in the region where the cancer cells are located. The microspheres are trapped in the arterioles which feed the tumors, and the β-particles annihilate the cancer cells. The glass particles must be spherical to avoid unnecessary bleeding, and the particle size must be restricted to a range which optimizes the blocking effect. Glass microspheres can be produced by heating glass particles using a flame or in a hot zone of a furnace. The particle size distribution is not easily predicted since it depends on the variation of the aspect ratio and the presence of agglomerates. In the present work, the spheronization process to obtain microspheres with diameters appropriate for radiotherapy treatment is evaluated. Samples were characterized by X-rays diffraction and Energy Dispersive X-rays Fluorescence Spectroscopy. The glass dissolution rate was determined in water at 90°C, and in Simulated Body Fluid (SBF) at 37°C. Glasses with dissolution rates close to 10-8g/(cm2.d) were obtained, which make them suitable for the present application. Scanning Electron Microscopy was used to evaluate the surface of the microspheres before and after the dissolution tests.