An alpha edge?

摘要

Dr. Cheetham and Dr. Petrylak have provided a most helpful review of the available data on use of radium-223 dichloride (~223RaCl_2), known as Alpharadin, in the treatment of osteoblastic metastatic prostate carcinoma. A technique for separating the daughter ~223Ra from the parent ~227Ac has been developed at the Department of Energy Hanford Site, Office of National Isotope Programs.[1,2] Alpharadin appears to be the first bone-seeking radiopharmaceu-tical to prolong the life span; the beta-emitting bone seekers (rhenium-186 HEDP [~186Re-HEDP], rheni-um-188 HEDP [~188Re-HEDP], samarium-153 lexidro-nam [~153Sm-lexidronam], and strontium-89 chloride [~89SrCl_2]do not.[3]Life prolongation by Alpharadin is presumably due to the greater local cytocidal capability of its alpha-particle emission. The alpha particle is a helium nucleus containing two protons and two neutrons; it carries a 2+ charge, and it has about 7300 times the mass of a beta particle or electron (carrying a 1- charge).