Capintec announces new calibration number for F-18

Capintec is a world leader in activity measurements for nuclear medicine.  Our sensitivity response curve was developed by direct measurement of almost 200 different isotopes from reference laboratories.  This level of detail and commitment to scientific accuracy enables Capintec to provide calculated numbers for additional isotopes which supports research efforts in many scientific areas.  Published information is based upon the best available processes at the time measurements were conducted.  However, data may change over time.  Capintec is committed to continual improvement. Consequently, when new referenced data is available, we will update our calibration information, and advise customers of any published changes.  

The National Institute for Standards and Technology (NIST)1, has conducted additional studies on the calibration of F-18 for Capintec calibrators.  Based on their report, Capintec is changing the published calibration number for F-18 to 472 for the following dose calibrators: CRC 25R, 25W, Ultra-R, 15R, 15W, 15Beta, and 127R.  The calibration number for F-18 for the PET series: CRC 25PET, Ultra-PET, and 15PET (which have reduced gas pressure) was derived from direct inter-comparison with the CRC 25R.  Repeated inter-comparisons have confirmed a new calibration number of 480 for all PET units. This change represents a +6.4% difference from the previously published value. 

Our flexible software permits the user to update calibration numbers if required for all microprocessor controlled units.  Easy to follow directions are available in the Operator’s Manuals.

Note that Capintec’s published calibration numbers are based on the NIST standard reference material (SRM) geometry. The SRM is a flame sealed glass ampoule with 0.6 mm wall thickness containing approximately 5 ml of solution.  This geometry provides a good approximation for vials and syringes of most frequently used isotopes.  However, isotopes with a significant abundance of low energy photons, or those with significantly different configurations may require geometry correction factors.  Since the radiopharmaceutical industry supplies isotopes in a wide variety of containers and housings, Capintec recommends that the user confirm geometry correction factors for individual vials, syringes, capsules, or sealed source models when possible.  This can be easily performed by requesting a NIST traceable source or solution directly from your radiopharmacy in the appropriate container or sealed source configuration.  Alternately, regional ADCL laboratories are available for most therapy calibration requirements.

To change the stored calibration number for F-18:

• Press the ‘Home’ key to return to the main screen
• Press the ‘Util’ or ‘Menu’ key
• Select ‘Set-up’
• Select ‘Other’
• Enter password (in most cases, the last three numbers of your serial number)
• Select ‘Nuclide Data’ (or ‘Nuclides’)
• Select ‘Cal Numbers’ (or ‘New Cal Number’)
• Choose F-18 via NUCL key (press ‘318’), pre-set nuclide key or user key
• F-18 data will be displayed – select the ‘9’ key to answer ‘Yes’ for ‘Change Cal #?
• For dose calibrator model CRC25R, 25W, Ultra-R, 15R, 15W, enter ‘472’
• For dose calibrator model CRC25PET, Ultra-PET, 15PET enter ‘480’
• After the calibration number is entered, the original and new calibration numbers will be displayed for verification

For additional information, contact Technical Support at (800) 631-3826.

*Cessna, J.T., Schultz, T. Lesle, T., Bores, N. 2008. Radionuclide calibrator measurements of 18F in a 3 ml plastic syringe. Applied Radiation and Isotopes. 66, 988-993.

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