A Revisit of SUV Values and Dose Calibrator Factors

Medical Physics Consultants, Inc

You may have recently received an email from Cardinal Health regarding the FDG settings on your Capintec dose calibrator.  The gist of the email was to remind customers of a 2009 revision to published calibration factors for F-18 utilizing Capintec dose calibrators.  If you have purchased a new dose calibrator since 2009 from Capintec (models that could possibly be effected are CRC-15R, CRC-25R, CRC-25W, CRCUltra-R, CRC-15W, CRC-127R, CRC-15 PET, CRC-25PET and CRCUltra-PET) you will want to ensure your calibration factors are in close agreement with your nuclear pharmacy’s calibration factors.   Furthermore, we want to remind you of a few key things should you need to adjust your dose calibrator.

Anytime you adjust your F-18 calibration factor, it is important to immediately perform an SUV calibration on your PET/CT scanner to ensure SUV measurements remain accurate.  Each manufacturer has its own name for SUV calibration, including “SUV Calibration”, “Cross Calibration”, and “Well Counter”.  Also keep in mind, manufacturer instructions for performing the calibration should be carefully followed.

In addition to changes in F-18 calibration factors, other circumstances could affect SUV measurements.  These, in addition to putting a new dose calibrator into service, include upgrading a scanner with an additional ring of detectors, failure to account for daylight savings time, and incorrect assessment of residual activity post-injection.  Remember, accurate measurements of SUVs rely on the interplay of the PET/CT scanner and the dose calibrator.  Anything that could affect that interplay, either on the scanner side or the dose calibrator side, can introduce inaccuracies.

If you have any questions about the accuracy of your SUV measurements don’t hesitate to ask your MPC physicist for advice on how you should proceed.