- Nuclear Medicine Physics, a Handbook for teachers and students, 2014 (IAEA)
- Quality Assurance for Radioactivity Measurement in Nuclear Medicine - Technical Report Series, No. 454, 2006 (IAEA)
- Quality control of nuclear medicine instruments, TECDOC-602, 1991 (IAEA)
- Busemann Sokole E., Acceptance testing for nuclear medicine instrumentation, Eur J Nucl Med Mol Imaging. 37 (2010) 672
- Publications EANM - guidelines
- Measurement Good Practice Guide No. 93 - Protocol for establishing and maintaining the calibration of medical radionuclide calibrators and their quality control, 2006 (NPL)
- The Selection, Use, Calibration, and Quality Assurance of Radionuclide Calibrators Used in Nuclear Medicine, Report No.181, 2012 (AAPM)
- Radiation Protection of the Patient. Nuclear Medicine. Optimization of Medical Exposure. Diagnosis (IAEA) - Presentation
- Zanzonico P., Routine Quality Control of Clinical Nuclear Medicine Instrumentation: A Brief Review, J Nucl Med, 49 (2008) 1114
- Calibration and Usage of "Dose Calibrator" Ionization Chambers for the Assay of Radionuclides (ANSI)
- Usage of Ionization Chamber Systems for Assay of Radionuclides, 1992 (IEC)
- Equipment: Radionuclide Calibrators – Particular Methods for Describing Performance, 1994 (IEC)
- Nuclear medicine instrumentation -Routine tests - Part 4: Radionuclide calibrators, 2006 (IEC)
The levels of activity in radiopharmaceuticals that are administered clinically are governed primarily by the need to balance the effectiveness and the safety of the medical procedure by choosing the minimum radiation dose delivered to the patient needed to achieve the required objective (e.g. diagnostic image quality or therapeutic outcome). Thus, accurate and reproducible measurement of radioactivity in nuclear medicine applications is vital to ensure these objectives. The need to maintain a high degree of confidence in those measurements requires a regular quality control of the instrument carried out in accordance with national and international standards. The most commonly used equipment for activity determination is a well-type gas ionisation chamber, where the activity is measured in terms of the ionisation current. The chamber is sealed under pressure and the gas is usually a noble gas with a high atomic number in order to increase the probability of photon interaction.
The calibration of the instrument is generally made at the place of manufacture using standard sources with activities that are traceable to a standard laboratory. A certificate should accompany the instrument. The objective of a regular quality control programme is to maintain the original function of the instrument, and assure its correct use. The quality control programme generally consists of daily, weekly, monthly and yearly checks and should include: test of precision and accuracy, test of linearity of activity response, test of reproducibility and check of background. The sources needed to perform the tests should include a sealed reference source certified to less than +/-5% overall uncertainty. Examples of suitable sources are Co-57, Ba-133, Cs-137 and Co-60.
Introduction to references
The IAEA document on Quality Assurance of Radioactivity Measurement in Nuclear Medicine covers all aspects of a QA-programme. More specific recommendations regarding a quality control programme for the radionuclide calibrator is found in IAEA-TECDOC-602 and also on the IAEA Radiation Protection of the Patient website. Guidance on the quality controls that should be undertaken on a routine basis for medical radionuclide calibrators to ensure the accuracy and traceability of measurements of the activities of radiopharmaceuticals is given in the Good Practice Guide No. 93 of the UK National Physical Laboratory. A general overview of quality control of nuclear medicine instrumentation is provided in the article by Zanzonico. The European Association of Nuclear Medicine has published general recommendations on routine testing of equipment including the radionuclide calibrator. More information can be found in the the IAEA Handbook, a comprehensive volume of Physics in Nuclear Medicine, published in early 2014.