Calibration of 32P "hot-wall" angioplasty-balloon-catheter sources by liquid-scintillation-spectrometry-based destructive radionuclidic assays.
A very quantitative, destructive-analysis procedure was devised for assaying the 32P activity content of "hot-wall" angioplasty-balloon catheters. These sources, developed and under investigation by Radiance Medical Systems, Inc. (Irvine, CA), are intended for use in the prophylactic inhibition of restenosis following balloon angioplasty in heart-disease patients. The assay was based on performing a physicochemical digestion of the balloon catheter to extract the 32P activity followed by liquid-scintillation (LS) spectrometry of the resultant solutions. Measurement-based corrections were applied for the residual activity remaining in the digested balloon debris and in all of the digestion apparatus. The LS spectrometry, with 3H-standard efficiency tracing, utilized a previously-developed method for resolving the always-present 33P impurity. Initial ionization current measurements on the sources prior to the destructive assays led to the establishment of calibration factors that can be used for subsequent non-destructive radionuclidic measurements on similar balloon-catheter sources.
Collé
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Physics Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8462, USA. rcolle@nist.gov
D015906:Angioplasty, Balloon, Coronary; D001918:Brachytherapy / Q000379:methods*; D002138:Calibration; D006328:Cardiac Catheterization; D003327:Coronary Disease / Q000532:radiotherapy*; D006801:Humans; D010761:Phosphorus Radioisotopes / Q000032:analysis* / Q000627:therapeutic use*; D017785:Photons; D012008:Recurrence; D015203:Reproducibility of Results; D012588:Scintillation Counting / Q000379:methods*
D010761:Phosphorus Radioisotopes