Determining the Dial Settings for Atomlab Dose Calibrators ... - Biodex

DETERMINING THE DIAL SETTINGS FORATOMLAB DOSE CALIBRATORSFOR Ra-223JANUARY 2013A. M. ZIMMER, PhD.Professor of RadiologyNorthwestern University Medical SchoolNorthwestern Memorial HospitalChicago, ILFN: 13-055 7/13

A. Michael Zimmer, PhD., Northwestern University Medical School, Northwestern Memorial Hospital,Chicago, IL received a Ra-223 Standard from Europe as part of their participation in clinical trials.This standard was used to determine the correct dial value for two different models of Dose Calibrators –Atomlab 100 and Atomlab 500.Three of each of the dose calibrator models were used for the determination (referred hereafter to as DC1,DC2 and DC3.)Standard: Traceable Ra-223 Standard, 134 µCi in a vial, calibrated for December 31, 2012I. The Atomlab 100 Standard Dial Settings for Vial DeterminationBiodex Atomlab 100 Dose Calibrator Using A VialCalculated Dial Setting 28.0 Reading 228 µCiDC1 Dial Setting 16.5 Reading 134.6 µCiDC2 Dial Setting 16.2 Reading 134.5 µCiDC3 Dial Setting 15.9 Reading 134.1 µCiPercent variance between lowest and highest reading using DC3 was3.7%.Geometry: Placing vial in lowest dipper position and the syringedipper location resulted in an error of 0.3% using DC3.The Atomlab 500 Standard Dial Settings for Vial DeterminationBiodex Atomlab 500 Dose Calibrator Using A VialDC1 Dial Setting 17.2 Reading 134.5 µCiDC2 Dial Setting 17.7 Reading 134.0 µCiDC3 Dial Setting 16.6 Reading 134.3 µCiPercent variance between lowest and highest reading using DC3 was6.2%.Geometry: Placing vial in lowest dipper position and the syringedipper location resulted in an error of 0.4% using DC2.II.The Standard Dial Settings for Syringe DeterminationRa-223 calibration in syringe (5ml B-D syringe). Exactly 1.0, 2.0, 3.0, 4.0 and 5.0ml from the traceablestandard and changing the calibration setting to reflect the activity withdrawn.Biodex Atomlab 100 Dose Calibrator for SyringeSyringe calibration was performed on DC3. Results are graphically expressed in the attached graph. Dialvalues ranged from 15.9 for 1.0ml volume to 16.9 for the 5.0ml volume. The percent difference from thelowest to the highest dial setting, using the 1.0 ml as the standard, was 6.2%.Biodex Atomlab 500 Dose Calibrator for SyringeSyringe calibration was performed on DC2. Results are graphically expressed in the attached graph. Dialvalues ranged from 17.7 for 1.0ml volume to 18.8 for the 5.0ml volume. The percent difference from thelowest to the highest dial setting, using the 1.0ml as the standard, was 6.3%.

III. ConclusionBased on the readings for the three Atomlab 100 Dose Calibrators and also the three Atomlab 500 DoseCalibrators for both vial and syringe dial values, a mean value of 16.7 for the Atomlab 100 and 17.8 forthe Atomlab 500 would be appropriate for both vial and syringe settings. This would result in errors ofless than 5% when measuring both vials and syringes (5ml syringe with maximum volume of 5.0ml).Atomlab 100 Atomlab 500ml Dial ml Dial1 15.9 1 17.72 16.1 2 17.93 16.4 3 18.14 16.6 4 18.45 16.9 5 18.8