Conference proceeding
Assaying and PET imaging of Ytrrium-90: 1 >> 34ppm > 0
2004 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-7, Vol.6, pp.3412-3414
IEEE Nuclear Science Symposium and Medical Imaging Conference
01/01/2004
DOI: 10.1109/NSSMIC.2004.1466619
Abstract
Yttrium-90 is widely used to label radiopharmaceuticals with curative, or at least palliative intent. At present, both the quantitative assay, +/- 10% variation, and the in vivo imaging observe bremstrahllung from the 2.3 MeV beta(-). Detection of the positron, which is created in the E-0w-decay of the 1.78 MeV excited state with a 34 +/- 4 ppm branching ratio, are resolved with two detector systems. A high purity Ge spectrometer with calibrated efficiency clearly resolves the 511 keV annihilation with a 2/1 peak over the continuous bremstrahllung, providing +/- 5% precision in 10min of multichannel analysis. Secondly, a simple NaI detector pair in fast coincidence yields similar precision, with trues/randoms approximate to 1000/1 evident in the time spectrum and the on/off-axis counting rate. The Ge detector, more tolerant to distributed sources, was used to assay the filling of a micro-Derenzo phantom, charged with 50 MBq/ml of Y-90 chloride, imperfectly stripped from unused mu-spheres. Phantoms were scanned with a Concorde mu PET P4 and a CTI 933/04. The phantom's 1.6-2.4-3.24.04.8 mm holes are clearly resolved, and particulate residue is evident as a settled deposit. The mu PET sensitivity to a centered 37 MBq point source of Y-90 is approximate to 24 cps trues, 37 cps randoms and 270 kcps singles, with the 4-decade drop being the result of the miniscule positron branching. Imaging is slow, but the promise of quantitative dosimetry is essential for a rational application of Y-90 radiotherapeutic agents.
Details
- Title: Subtitle
- Assaying and PET imaging of Ytrrium-90: 1 >> 34ppm > 0
- Creators
- R J NicklesA D RobertsJ A NyeA K ConverseT E BarnhartM A Avila-RodriguezR SundaresanD W DickR J HammasB Thomadsen
- Contributors
- J A Seibert (Editor)
- Resource Type
- Conference proceeding
- Publication Details
- 2004 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-7, Vol.6, pp.3412-3414
- Publisher
- IEEE
- Series
- IEEE Nuclear Science Symposium and Medical Imaging Conference
- DOI
- 10.1109/NSSMIC.2004.1466619
- ISSN
- 1095-7863
- Number of pages
- 3
- Language
- English
- Date published
- 01/01/2004
- Academic Unit
- Pharmaceutical Sciences and Experimental Therapeutics; Radiology
- Record Identifier
- 9984318795702771
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