Glas

Analytical and Bioanalytical Chemistry -     

Microspheres Used in Liver Radioembolization: From Conception to Clinical Effects

Inert microspheres, labeled with several radionuclides, have been developed during the last two decades for the intra-arterial treatment of liver tumors, generally called Selective Intrahepatic radiotherapy (SIRT). The aim is to embolize microspheres into the hepatic capillaries, accessible through the hepatic artery, to deliver high levels of local radiation to primary (such as hepatocarcinoma, HCC) or secondary (metastases from several primary cancers, e.g., colorectal, melanoma, neuro-endocrine tumors) liver tumors. Several types of microspheres were designed as medical devices, using different vehicles (glass, resin, poly-lactic acid) and labeled with different radionuclides, ⁹⁰Y and ¹⁶⁶Ho. The relationship between the microspheres’ properties and the internal dosimetry parameters have been well studied over the last decade. This includes data derived from the clinics, but also computational data with various millimetric dosimetry and radiobiology models. The main purpose of this paper is to define the characteristics of these radiolabeled microspheres and explain their association with the microsphere distribution in the tissues and with the clinical efficacy and toxicity. This review focuses on avenues to follow in the future to optimize such particle therapy and benefit to patients.     

Alignment of Elementary Geometry Curriculum With Current Standards

The subject of geometry in the curriculum continues to be an area of concern among mathematics educators. The gap between standards expectations and actual textbook content continues to reflect the need for substantial change. In this study, the geometry language introduced in K‐6 textbooks was carefully examined and compared to the language used in the Curriculum and Evaluation Standards for School Mathematics ( National Council of Teachers of Mathematics, 1989 ), Principles and Standards for School Mathematics ( NCTM, 1999 ), and New Standards Elementary School Mathematics Performance Standards ( National Center for Education and the Economy, 1997 ). The. logic followed was that the language in textbooks reflects the content presented in the textbook, and the language in the standards reflects what should be presented. The results of the study clearly indicate that there is a substantial misalignment between the geometry presented in the textbooks, the. geometry expected to be taught by groups such as NCTM, and the geometry being assessed in student performance measures as suggested by NCEE. Specific areas of misalignment are identified, along with implications, and some areas in which the curriculum should be revised are identified.