System, Emanation Generator, and Process for Production of High-Purity Therapeutic Radioisotopes

Abstract

An isotope production system, emanation generator, and process are disclosed for production of high-purity radioisotopes. In one implementation example, high-purity Pb-212 and/or Bi-212 isotopes are produced suitable for therapeutic applications. In one embodiment the process includes transporting gaseous radon-220 from a radium-224 bearing generator which provides gas-phase separation of the Rn-220 from the Ra-224 in the generator. Subsequent decay of the captured Rn-220 accumulates high-purity Pb-212 and/or Bi-212 isotopes suitable for direct therapeutic applications. Other high-purity product isotopes may also be prepared.

1 . An emanation system for production of ultrapure radioisotopes, comprising:
 an emanation device having an emanation source comprising a source isotope therein that emanates a radioactive gas therefrom; and   a collection device configured to collect the radioactive gas retaining same for a time sufficient to yield one or more high purity radioactive daughter isotopes therein.   
     
     
         2 . The system of  claim 1  wherein the source isotope is selected from Thorium-228 and/or Radium 224; Thorium-227 and/or Radium-223; or Thorium-230 and/or Radium-226. 
     
     
         3 . The system of  claim 1  wherein the radioactive gas is selected from Radon-220; Radon-219; and Radon-222. 
     
     
         4 . The system of  claim 1  wherein the radioactive gas is a radioactive noble gas. 
     
     
         5 . The system of  claim 1  wherein the source isotope is disposed on a particle surface or a permeable support. 
     
     
         6 . The system of  claim 1  wherein the source isotope is disposed on magnetic or paramagnetic metal oxide particles. 
     
     
         7 . The system of  claim 1  wherein the source isotope is disposed on a gas-permeable support. 
     
     
         8 . The system of  claim 1  wherein the collection device includes a cooling device configured to cool the radioactive gas emanated from the emanation device. 
     
     
         9 . The system of  claim 1  wherein the collection device includes a soluble salt configured as a thin film or a packed salt, or a lipophilic liquid configured as a thin film or a thin film coating on a solid support to extract the radioactive gas emanated from the emanation device therein. 
     
     
         10 . The system of  claim 1  further including an eluent delivery device or system configured to deliver a fluid to recover the radioactive daughter isotopes from the collection device. 
     
     
         11 . The system of  claim 1  wherein the radioactive daughter isotopes are selected from Pb 212 and/or Bi-212; Pb-211 and/or Bi-211; and Pb-214 and/or Bi-214; and daughter isotopes thereof. 
     
     
         12 . An emanation system for production of ultra-pure isotopes for radiotherapeutic applications, comprising:
 an emanation generator comprising a radium source configured to generate a radioactive gas that is emitted separating same therefrom; and   a collection device configured to collect and retain the emitted radioactive gas for a time sufficient to decay the gas therein yielding one or more radioactive daughter isotopes therefrom.   
     
     
         13 . A method of producing high purity radioisotopes, comprising the steps of:
 emanating a radioactive gas generated in a source material comprising a source isotope to separate the radioactive gas as a pure product therefrom; and   collecting the separated radioactive gas and retaining same for a time sufficient to decay the radioactive gas to yield one or more high purity radioactive daughter isotopes therefrom.   
     
     
         14 . The method of  claim 13  wherein the source isotope is selected from Thorium-228 and/or Radium 224; Thorium-227 and/or Radium-223; or Thorium-230 and/or Radium-226 
     
     
         15 . The method of  claim 13  wherein the radioactive gas is selected from Radon-220; Radon-219; and Radon-222. 
     
     
         16 . The method of  claim 13  wherein the radioactive gas is a radioactive noble gas. 
     
     
         17 . The method of  claim 13  wherein the collecting step includes cooling the emanated radioactive gas with a cooling device or cryogen to condense or deposit the emanated radioactive gas. 
     
     
         18 . The method of  claim 13  wherein the collecting step includes extracting the radioactive gas on a thin film or a packed column comprising a soluble salt; or in a thin film or thin film coating comprising a lipophilic material on a solid support. 
     
     
         19 . The method of  claim 13  wherein the radioactive daughter isotopes are selected from Lead 212 and/or Bismuth-212; Lead 211 and/or Bismuth-211; and Lead-214 and/or Bismuth-214 and daughter isotopes thereof. 
     
     
         20 . The method of  claim 13  further including the step of recovering the radioactive daughter isotopes in a fluid such as a biologically-compatible aqueous solution.