Introduction

These recommendations cover routine quality control (QC) of instrumentation used within a nuclear medicine department. Routine QC testing starts after installation of the instrument, and after acceptance testing, and continues on a regular basis throughout its lifetime. Additional periodic tests may be carried out to provide more in-depth testing. Recommendations for acceptance testing are covered in a separate document. These recommendations must be considered in the light of any national guidelines and legislation, which must be followed. The recommendations cover the types of tests to be performed, and suggested frequencies, but they do not specify the protocols to be followed, which are available from other reference sources quoted.

Acceptance and reference tests

After installation, and before it is put into clinical use, a nuclear medicine instrument must undergo thorough and careful acceptance testing, the aim being to verify that the instrument performs according to its specifications and its clinical purpose. Each instrument is supplied with a set of basic specifications. These have been produced by the manufacturer according to standard test procedures, which should be traceable to standard protocols, such as the NEMA and IEC performance standards [1–4, 11, 17, 30, 37]. By following such standard protocols in the clinical setting, with support from the vendor for supplying phantoms and software where necessary, specifications can be verified and baseline performance data created. Additional tests are usually also needed in order to more thoroughly test individual components of an instrument. These acceptance test results form the reference data for future QC tests, and some may be repeated periodically, such as at half-yearly or yearly intervals, or whenever a major service or component change has been carried out.

Routine tests

Once the instrument has been accepted for clinical use, its performance needs to be tested routinely with simple QC procedures that are sensitive to changes in performance. Tests must be performed by appropriately qualified and trained staff, and detailed local operating procedures should be written for this routine work. All test results must be recorded and monitored for variations, and appropriate actions taken when changes are observed. The QC tests are an important part of the routine work, and sufficient equipment time and staff time must be allocated for routine QC.

Action thresholds, follow-up, record keeping and review, and monitoring

Records of test results should be kept in a log-book or digital record. Immediate review of the QC results is essential, comparing them to the usual values obtained, and to the action thresholds for that test. Action thresholds should be set locally, taking into account the manufacturer’s recommendations, and other professional guidance. Action thresholds should be set to maintain the system within the specification value of a parameter. When action thresholds are reached a decision needs to be made about whether the instrument is fit for use. The QC operating procedure should make clear the actions to be taken when an action threshold is reached or exceeded, and who is responsible for the decision to use the equipment.

The follow-up actions taken when test results are unsatisfactory and solutions to a problem must be recorded. Such a record may assist troubleshooting if a similar problem occurs.

Routine test recommendations and test frequency

Recommendations for basic routine QC tests that should be scheduled and carried out for the main instruments of the nuclear medicine department are presented in Tables 1, 2, 3, 4, 5, 6, 7, 8 and 9. The tables give briefly the purpose of the test, suggested frequency, and a comment. These are not intended to supersede national guidelines or national regulations, which should always be followed. The test frequencies given should be followed and adjusted according to observations of instrument stability and environmental stability (power supply, temperature and humidity). Where the frequency is indicated as a dual time period, e.g. weekly/monthly, it is recommended that tests are carried out at the shorter time period, and that the test frequency is only reduced if regular testing gives evidence that the system is stable. There is also a note in the legend to each table giving the general type of technology that the recommendations apply to. Specific systems may employ technologies that need other checks, as specified by the manufacturer.

Table 1 Routine QC tests for a gamma camera: planar, whole-body, SPECT and SPECT/CT. Equipment type: scintillation Anger gamma camera
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Table 2 Routine QC tests for PET and PET/CT. Equipment type: coincidence, scintillator system (fixed and mobile systems)
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Table 3 X-ray CT – applies to PET/CT and SPECT/CT
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Table 4 Routine QC tests for a radionuclide calibrator. Equipment type: gas ionization chamber; the checks also apply to scintillation based calibrators, but additional checks may apply (see manufacturer’s documentation)
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Table 5 Routine QC tests for a thyroid uptake probe. Equipment type: nonimaging scintillation detector
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Table 6 Routine QC tests for a nonimaging intraoperative probe. Equipment type: nonimaging gamma ray detecting probe; any type of detector
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Table 7 Routine QC for an in vitro manual or automatic gamma counting system. Equipment type: single-sample or multisample gamma counter, with scintillation detector
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Table 8 Routine QC for radiation monitoring instruments: exposure meter, contamination monitor, personnel monitor. Equipment type: any type of ionizing radiation detection monitor. The radiation protection adviser should be consulted to ensure compliance with national legislation and guidance on radiation dose measuring instruments
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Table 9 Routine QC tests for a preclinical PET. Equipment type: small-animal positron emission tomograph
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It is a principle of radiation safety and patient protection to ensure that before the administration of a radiopharmaceutical there is suitable equipment to complete the procedure, and that the equipment is functioning correctly. The correct basic function of the device must always be checked after any engineering intervention for repair or calibration, and appropriate engineer’s checks may satisfy this need.

Note: The clocks within the department, within all instruments and all computers must be synchronized and checked daily/at least weekly. This is an essential requirement for accurate activity administration and quantitative data analysis.

Procedures and references

Test procedures are not included in this document, but can be found by reference to standard descriptions (e.g. [1–4]) and national and international protocols. Any manufacturer-supplied test procedures, test phantoms and software should also be taken into account when writing local operating procedures. Some essential literature references are given. They should be consulted for detailed generic test procedures and advice regarding test evaluation, action thresholds and follow-up. It is recommended that each department create detailed written routine QC test procedures specific for each instrument in use. By following standard QC procedures, consistency in test results can be assured and trends monitored.