PT - JOURNAL ARTICLE AU - Jean-François Valley AU - Shelley Bulling AU - Michel Leresche AU - Claude Wastiel TI - Determination of the Efficiency of Commercially Available Dose Calibrators for β-Emitters DP - 2003 Mar 01 TA - Journal of Nuclear Medicine Technology PG - 27--32 VI - 31 IP - 1 4099 - http://tech.snmjournals.org/content/31/1/27.short 4100 - http://tech.snmjournals.org/content/31/1/27.full SO - J. Nucl. Med. Technol.2003 Mar 01; 31 AB - Objectives:The goals of this investigation are to determine whether commercially available dose calibrators can be used to measure the activity of β-emitting radionuclides used in pain palliation and to establish whether manufacturer-supplied calibration factors are appropriate for this purpose. Methods:Six types of commercially available dose calibrators were studied. Dose calibrator response was controlled for 5 γ-emitters used for calibration or typically encountered in routine use. For the 4 most commonly used β-emitters (32P, 90Sr, 90Y, and 169Er) dose calibrator efficiency was determined in the syringe geometry used for clinical applications. Efficiency of the calibrators was also measured for 153Sm and 186Re, 2 β-emitters with significant γ-contributions. Source activities were traceable to national standards. Results:All calibrators measured γ-emitters with a precision of ±10%, in compliance with Swiss regulatory requirements. For β-emitters, dose calibrator intrinsic efficiency depends strongly on the maximal energy of the β-spectrum and is notably low for 169Er. Manufacturer-supplied calibration factors give accurate results for β-emitters with maximal β-energy in the middle-energy range (1 MeV) but are not appropriate for use with low-energy (169Er) or high-energy (90Y) β-emitters. β-emitters with significant γ-contributions behave like γ-emitters. Conclusion:Commercially available dose calibrators have an intrinsic efficiency that is sufficient for the measurement of β-emitters, including β-emitters with a low maximum β-energy. Manufacturer-supplied calibration factors are reliable for γ-emitters and β-emitters in the middle-energy range. For low- and high-energy β-emitters, the use of manufacturer-supplied calibration factors introduces significant measurement inaccuracy.