biodex ATOMLAB 500, Operation And Service Manual, Page: 185 / 212

Typically, the CDV will be higher than the DV for glass wall source containers when the isotope
has a significant portion of low energy photons in its emission spectrum.
Scheme: EC = Electron Capture IT = Isomeric Transition
Notes:
1.
Isotope: A/B implies that B is in equilibrium with A.
2.
Half life : s = seconds, m = minutes, d = days, y = years.
3.
Scheme: E = electron capture, B – beta decay, IT = isomeric transition, A = alpha decay.
4.
Cal Value: Atomlab dose calibrator dial setting to calibrate for corresponding isotope
5.
Notes:
*H(r) = Half life ratio of daughter over parent, implies daughter is ignored.
** Bremsstrahlung includes low energy photons from electron interaction in saline.
Isotope should be measured in plastic syringe or vial or thin wall glass ampule unless otherwise
stated above.
Table E.2. Confidence Values
Value Description
C Calculated with corrected Monte Carlo.
B
Beta MC; response strongly dependent upon measurement geometry. Best if Cal
Value used is determined using actual measurement with clinical geometry
confidence value of a measurement made using the listed dial value.
M Measured directly.
S Special Case.
+/- 3% As stated.
Dial Settings for Y-90
The typical Atomlab 500 Dose Calibrator dial setting for Y-90 activity in a 10 cc plastic syringe
is 350. This value can be used as a starting point for initial measurements. However, it is
recommended that the dial setting used for clinical measurements is determined from the first
dose of Zevalin received from the radiopharmacy as outlined below. Following doses are
compared to the radiopharmacy doses for constancy.
Using the Atomlab Dose Calibrator, the Y-90 recipient should determine the correct dial value
from the first Y-90 dose received from a commercial radiopharmacy. This is determined by
selecting the Y-90 button and adjusting the dial setting until the displayed activity agrees with
the decay-corrected Y-90 syringe activity as stated by the commercial radiopharmacy. The third
Y-90 Sir-Spheres has a dial value of 433.3. If the adjusted dial setting falls within the range of
333 to 433.3, use that dial setting.
If it falls outside the range, verify that:
•
There is a well liner in place.
•
A hook-style dipper is used.
•
The annual accuracy and Daily Constancy Test results are acceptable.