RT Journal Article SR Electronic T1 Dispensing Therapeutic Amounts of Holmium-166 with a Radionuclide Calibrator JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 275 OP 278 VO 23 IS 4 A1 Diaz, M. A1 Macey, D. J. A1 Kasi, L. P. A1 Bayouth, J.E. A1 Podoloff, D.A. YR 1995 UL http://tech.snmjournals.org/content/23/4/275.abstract AB Objective: A high-purity germanium detector (HPGe) spectrometry system was used to calibrate a radionuclide calibrator for the accurate dispensing of therapeutic amounts of 166Ho to be administered to patients. Methods: A calibrated 60Co source was counted simultaneously in the same geometry as the 166Ho for acquisition of gamma ray spectra. The sensitivity of the HPGe detector for the 1.379-MeV photons emitted by 166Ho was determined from the 1.333-MeV photons emitted from 60Co. This measured amount of 166Ho was placed in an assay calibrator and the sensitivity control adjusted so that the readout matched the 166Ho content. Results: The dial setting required for the Capintec CRC-15R was found to be 748 times 10. Conclusion: This assay of 166Ho with a HPGe detector has proved useful for adjusting the sensitivity of a clinical radionuclide calibrator and can be extended to provide calibration factors for other assay calibrators used to dispense therapeutic amounts of other radionuclides used for clinical nuclear medicine procedures.