International guidance on the establishment of quality assurance programmes for radioactivity measurement in nuclear medicine

Tele-nuclear medicine

This article presents a description of tele-nuclear medicine and, after outlining its history, a wide, representative range of its applications. Tele-nuclear medicine has benefited greatly from technological progress, which for several decades has provided greater data transfer rates and storage capacity at steadily decreasing cost. Differences in the practice of nuclear medicine between developed and developing countries arise mainly from disparities in their available infrastructure, funding and education levels of personnel involved. Consequently there are different emphases in their tele-nuclear medicine, which are elaborated. It is concluded that tele-nuclear medicine is important for all countries, but the emphasis on its application may differ between developed and developing nations, with an emphasis on distance learning in the latter.

Usefulness of specific calibration coefficients for gamma-emitting sources measured by radionuclide calibrators in nuclear medicine

PURPOSE

In nuclear medicine, the activity of a radionuclide is measured with a radionuclide calibrator that often has a calibration coefficient independent of the container type and filling.

METHODS

To determine the effect of the container on the accuracy of measuring the activity injected into a patient, The authors simulated a commercial radionuclide calibrator and 18 container types most typically used in clinical practice. The instrument sensitivity was computed for various container thicknesses and filling levels. Monoenergetic photons and electrons as well as seven common radionuclides were considered.

RESULTS

The quality of the simulation with gamma-emitting sources was validated by an agreement with measurements better than 4% in five selected radionuclides. The results show that the measured activity can vary by more than a factor of 2 depending on the type of container. The filling level and the thickness of the container wall only have a marginal effect for radionuclides of high energy but could induce differences up to 4%.

CONCLUSIONS

The authors conclude that radionuclide calibrators should be tailored to the uncertainty required by clinical applications. For most clinical cases, and at least for the low-energy gamma and x-ray emitters, measurements should be performed with calibration coefficients specific to the container type.

Quality audit programme for (99m)Tc and (131)I radioactivity measurements with radionuclide calibrators

The use of radiopharmaceuticals in nuclear medicine for diagnosis and therapy has increased over the years with (99m)Tc and (131)I being most widely used. Quality audit programmes for radioactivity measurements of (131)I have been ongoing and the 12th audit was recently conducted among seventy nuclear medicine centres (NMC) in India. An audit for the activity measurements of (99m)Tc was conducted for the first time among ten NMCs in Mumbai, India. These programmes for radioactivity measurements have become very important to establish traceability of measurements to national and international standards and ensure accurate calibration of radionuclide calibrators. The results of both the audits are very encouraging. Ninety-four percent of the NMCs for (131)I activity measurements were within a window of +/-10% and for (99m)Tc one NMC was deviating more than +/-10%. The methodology adopted for the audit and results are discussed in detail in this paper.