Measurement standards for strontium-89 for use in bone palliation

Comparison of strontium-89 solution sources in UK hospitals, 2003

Concerns have been raised within the nuclear medicine field about the accuracy of measurements of 89Sr. The 85Sr impurity present in the 89Sr solution has a significant effect on the response of radionuclide calibrators used in hospitals. A comparison was conducted between the National Physical Laboratory (NPL) and the UK hospital physics community. Only 58% of the results were within 5% of the NPL value. Work at NPL has resulted in correction factors for the NPL secondary standard radionuclide calibrator and for Capintec calibrators, which will produce a significant improvement in performance.

Standardization of a 89Sr solution from a BIPM intercomparison using a liquid scintillation method

A procedure to standardize 89Sr (as strontium chloride) solutions, within the frame of a BIPM intercomparison, by the CIEMAT/NIST method was presented for Instagel Plus, HiSafe III and Ultima Gold liquid scintillation cocktails. The stability was studied for two types of samples: those obtained by direct addition of the 89Sr solution and those by the extra addition of 0.5 ml of HCl (0.1 mol l(-1)) to the cocktails. The results only showed good stability with the three scintillants used when additional HCl was added to the cocktails. The activities per unit mass determined for 89Sr were: 26.344 kBq g(-1) for Instagel Plus; 26.335 kBq g(-1) for HiSafe III; and 26.310 kBq g(-1) for Ultima Gold (at a reference time of 2000.10.01, 00 h UT) with a total uncertainty of 0.5% in each case (k = 1).