ABSTRACT
Standardization of (153)Sm by 4π(LS)-γ coincidence and anticoincidence counting and the CIEMAT/NIST method in three LS-counters is presented. This short half-life radionuclide is applied in tumor therapy and bone pain palliation. A simplified disintegration scheme of (153)Sm was applied in the calculation of the counting efficiency. Standard uncertainties of 0.4% for the (153)Sm measurements by the 4π(LS)-γ coincidence and anticoincidence techniques and 0.7% by the C/N method were evaluated, respectively. An agreement of the standardization results by both methods within the respective uncertainties was obtained. The half-life of (153)Sm of (1.92895±0.00024) days was determined during one month of measurements and correction for europium isotope impurities by the C/N method in the TriCarb 2910 LS-counter.
Subject(s)
Samarium/analysis , Half-Life , Humans , Reference Standards , Samarium/pharmacokinetics , Samarium/standards , Solutions , UncertaintyABSTRACT
A (85)Sr solution was measured in two liquid scintillation (LS) counters. Scintillation pulses from the delayed transitions in the (85)Sr decay were by and large lost as the dead time of the LS-counter was much longer than the lifetime of the (85)Rb excited level. The registration probability of these pulses has been defined and introduced into the counting efficiency calculation. The results of the (85)Sr solution standardization by the CIEMAT/NIST and the TDCR methods relative to the results from the 4π(LS)-γ coincidence and anticoincidence method were 0.997±0.012 and 0.971±0.019, respectively.
Subject(s)
Algorithms , Radioisotopes/analysis , Radioisotopes/standards , Radiometry/methods , Radiometry/standards , Strontium Radioisotopes/analysis , Strontium Radioisotopes/standards , Half-Life , Internationality , Radiation Dosage , Radioisotopes/chemistry , Radiometry/instrumentation , Reference Standards , Reference ValuesABSTRACT
The Radioisotope Centre (RC) has organized for the first time in Polish hospitals a comparison of activity measurements of (99)Tc(m) and (131)I. From the 58 Polish hospitals invited, 37 participated in the comparison. Each participant got about 4 mL of (99)Tc(m) eluate and two (131)I capsules, low- and high-activity. Sources were standardized in the RC before dispatch using a 4pi ionization chamber calibrated by standard solutions. Participants used their own radionuclide calibrators. The measurement results were evaluated using the E(n) criterion and the z'-score. From all 118 measurement results received from participants, 75 results (64%) lay within +/-5% of the RC value, and 99 results (84%) lay within +/-10.0%.
