<b>Theraspheres and Sirspheres</b>

This would be a technique whereby the selective catheterization of tumor-supplying arteries would result in embolization of the arteries with either glass beads or resin impregnated with Yttrium-90. This would result in the radiation being discharged locally in the tumor.  Currently this technique is only under investigation for treatment of liver metastases, not bone metastases.   However, it would seem to lend itself to treatment of bone metastases.   

Whether the presence of the glass or resin will prevent subsequent RFA treatment of the area, or the presence of the Yttrium-90 prevent use of other agents subsequently is not known.  

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