An Alpha Autoradiographic Technique for Spatial Quantification of ¹B Concentrations in Tissue

Boron neutron capture therapy (BNCT) is an experimental radiation therapy that is being developed for the treatment of malignant tumors. One requirement for successful BNCT is that a sufficient amount of ¹⁰B concentrates in the tumor while clearing from normal tissues and blood. Many pharmaceuticals are currently being developed to selectively deliver ¹⁰B to a tumor. To evaluate the effectiveness of various ¹⁰B delivery agents, the concentrations of boron in blood, tumor, and normal tissues must be known. Using the solid-state nuclear track detector CR-39, a tissue assay technique has been developed to spatially determine ¹⁰B concentrations in tissue samples. The technique has been used to quantify ¹⁰B concentrations in tumor and normal tissue on lines across rat brain tissue sections. This was done by combining ¹⁰B concentrations measured on lines across the CR-39 with color digital images of the tissue section. Coupling the methodology that was developed for tissue samples with an existing analytical technique for blood-¹⁰B concentration measurements allows for complete evaluation of ¹⁰B distributions in blood, tumor, and normal tissues and should be useful in evaluating various ¹⁰B delivery agents for use in BNCT.