Calicheck Manual

Nuclear Associates 34-210

Calicheck™ Dose Calibrator Linearity Test Kit

Users Manual

March 2005
Manual No. 34-210-1 Rev. 2
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139
440.498.2564

www.flukebiomedical.com/rms

Table of Contents

Section 1: General Information................................................................................... 1-1
1.1 General Information ..................................................................................... 1-1

Section 2: Calicheck Calibration ................................................................................ 2-1

2.1 Calibration of Calicheck ............................................................................... 2-1
2.2 Calibration Procedure .................................................................................. 2-2
2.3 Data Treatment of Data Sheet #1 ................................................................ 2-3

Section 3: Activity Linearity Procedure ..................................................................... 3-1

3.1 Activity Linearity Procedure ......................................................................... 3-1
3.2 Date Treatment of Data Sheet #2 ................................................................ 3-2

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1General Information
General Information

Section 1

General Information

1.1 General Information

Several important points must be understood prior to using Calicheck. The points are as follows:

1. Calicheck performs thorough quality control on all kits. However, it is suggested that the kit be
checked to ensure that the kit has not been damaged in shipment.

2. The components of the kit and/or the dose calibrator can be damaged if misused. It is especially
important that damage does not occur to the ends of the tubes.

3. Calicheck confirms activity linearity. It will not make your dose calibrator linear.
4. The dose calibrator must exhibit activity linearity prior to utilizing the Calicheck kit. This must be

accomplished by performing an activity linearity test using standard techniques such as described
in your license application. For NRC license holders, this test should be at a minimum equivalent to
Appendix C of Regulatory Guide 10.8, August 1987. If non-linearity is demonstrated, the instrument
should be repaired.
5. Calicheck must be specifically calibrated for each dose calibrator in the facility since variations
between manufacturers (and sometimes, models) are known to exist. Similarly, kits should not be
interchanged without first confirming calibration factors. Each tube in the Calicheck kit must be
calibrated and each time a tube is replaced in the kit, the new tube must be calibrated. A procedure
is enclosed that describes the calibration technique.
6. Readings obtained from Calicheck are not to be used for assay purposes.
7. The radionuclide used for testing must be Tc-99m, and it must be relatively free of Mo-99
contamination. The concentration of Mo-99 in the sample should be less than .01 uCi Mo-99/mCi
Tc-99m. If a central radiopharmacy is used as the source of TC-99m, ask the radiopharmacist for
his assay results.
8. Do not use the tubes as shielding devices. The black center tube offers absolutely no radiation
protection since it is plastic with no lead in its wall. The other tubes do contain varying amounts of
lead, but should never be regarded as a protective shield.
9. The entire kit should be stored in the mailing container in an upright position when not in use. The
black center tube should be inserted base down into the purple-banded tube.
10. Typically, regulatory agencies, such as the Nuclear Regulatory Commission or state licensing
agencies, require that methods for activity linearity evaluations be filed with them in the form of a
license amendment application. A sample letter requesting authorization to use Calicheck, to be
sent to the regulatory agency, is located on page 1-3, License Amendment Request. Simply fill in
the blanks, transfer entire letter to hospital stationery, have the application signed and forward to
your licensing agency. Include amendment fees, where applicable. Upon receipt of the amendment,
Calicheck can be put to use.

CAUTION

Calicheck should only be used by qualified
personnel. Tubes should be carefully placed into
the dose calibrator to avoid damage to the tube
and/or chamber itself.

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Outer Lead SleeveNuclear Associates 34-210
Operators Manual

1.2 Product Description

Calicheck is a kit designed to perform the activity linearity test on a dose calibrator quickly and accurately.
The kit consists of seven tubes, six of which are lead-lined to attenuate gamma radiation from radioactive
sources, and a seventh, unlined tube. Each lead-lined tube varies in the thickness of lead so as to
simulate various stages of radioactive decay. These tubes are sequentially placed over a source of
radioactivity in the dose calibrator and within minutes, up to twelve measurements can be acquired
representing values that would have been obtained from several hours to more than four days following
the initial assay of Tc-99m. The need for determining linearity by fractionating eluants, or decaying the
elution for several days while data is being collected, is eliminated - and greatly reduced radiation
exposures to personnel.
Each tube is coded with a colored band for identification.

Central
Tube
Source

Holder
Lead
Lead

Figure 1-1

1-2

License Amendment Request (sample) 1General Information
Product Description
(To be placed on licensee's stationary) Zip

NRC or State License State
Number:

Facility

Address

City

Person to be contacted regarding this application: Phone
(RSO, Technologist, Consultant, Doctor, Admin.)

Gentlemen:

Please amend out license as follows:

As an alternative to our present procedure, the dose calibrator can be cheeked for activity with the use of
a sleeve device from Calicheck. The manufacturer's instruction for use and revised August 1, 1989 will
followed. Test results will be recorded and retained for inspection. Corrective action as stated in our
license application will be followed if unacceptable linearity is demonstrated.

Sincerely,

Administrator

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Operators Manual

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2Operation

Calibration of Calicheck

Section 2

Operation

2.1 Calibration of Calicheck

Objective
To generate calibration factors for each tube in the Calicheck Kit, thereby expressing the amount of
attenuation by each tube.

Preparation
All radiation sources in the vicinity of the dose calibrator should be shielded to avoid erroneous readings.
Further, the instrument may be sensitive to dosed patients in the vicinity. Move the patients to another
location before you start. Both the "Kit Calibration" and the "Activity Linearity Procedure" must be
performed in an environmentally stable background.

Syringe hangers and vial holder assemblies supplied with Capintec, Fluke Biomedical, and some Picker
dose calibrators must be removed. Molded chamber liners as supplied by RadX and some Picker dose
calibrators must be lifted out. Calicheck will not fit in dose calibrators with a chamber well diameter
smaller than 2-3/8" inches.

In performing the kit calibration procedure, it is recommended you use the largest source of Tc-99m
available to you. In this way you will be able to calculate the greatest number of tube and tube
combination attenuation calibration factors.

In order to use Calicheck, a source of Tc-99m must be placed into the central black tube. If the source is
in a top loading lead elution shield, use extension tongs to transfer the source. If the source is in a bottom
loading elution shield, remove the base cover, put the open end of the black tube to the bottom of the
lead shield and allow the source to slide down into the black tube by tilting the tube at an angle. The
center tube accommodates vial sizes up to 20 ml and syringes up to 10 ml. Proper technique dictates that
when using a syringe, a clean needle be used and it should be no longer than 1 ½" in length. When the
black tube is inserted into the dose calibrator, it should be done carefully with the open end in the upward
position. The black tube must remain in the dose calibrator throughout all steps in the calibration cycle.
Once the source is placed in the dose calibrator, the source must be kept in exactly the same position
throughout the test to insure consistent geometry.

If the unit has a manual range adjust, adjust the range as necessary to acquire at least three significant
figures for each reading.

Dose calibrator assays less than 1 00 uCi are highly errant and require close scrutiny to assure a true
interpretation of floating displays. Give the unit time to "settle down". For fixed displays, take multiple
readings and calculate the average for use in determining the tube correction factor. Dose calibrator
displays less than 10 uCi should not be relied upon for use in determining correction factors.

Once the procedure is started, do not stop. All readings should be recorded within a matter of minutes.
Otherwise, the short half-life of TC-99m will introduce unacceptable error. To completely eliminate error
due to decay, collect data from the maximum to minimum displayed readings and then reverse the order.
Average the two readings for each tube or tube combination and use this number. Record all values on
the data sheets in mCi units.

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Nuclear Associates 34-210
Operators Manual

2.2 Calibration Procedure

NOTE
To be performed only once or following repair of
dose calibrator or Calicheck.

1. Remove any syringe hanger or chamber liner, if necessary, from the dose calibrator.
2. Set dose calibrator to measure Tc-99m.
3. Adjust zero, background, etc., if applicable. Check zero on each range. If background is not "zero"

on all ranges, zero on one range and record values on all other ranges, to add or subtract from final
results when those ranges are used.
4. Place calibration source into black tube and insert black tube into dose calibrator CAREFULLY with
the open end in the upward position. Observe displayed activity.
5. Record reading in appropriate positions on the Data Sheet #1, "Kit Calibration." (Up to 12 entries
may be required. See example in Section 2.3.)

NOTE

Carefully ensure that, in the following steps, each
tube is firmly seated against the lead at the base of
the black tube. When the purple tube is used, care
must be taken to insure it is placed over the black
center tube such that is goes all the way down over
the base puck. Do not allow the purple tube to rest
eccentrically on the lead ring at the bottom of the
black center tube. All the other color tubes are
designed to rest on the lead ring.

6. Place red tube in the dose calibrator over the black tube. Record reading as the appropriate
denominator on the Data Sheet #1 "Kit Calibration."

7. Replace red tube with orange tube. Record.
8. Replace orange tube with yellow tube. Record.
9. Replace yellow tube with green tube. Record.
10. Replace green tube with blue tube. Record.
11. Replace blue tube with purple tube. Purple tube must go down over the base pedestal. Record.
12. Leaving the purple tube in place, install the red tube over the black central tube and into the purple

tube. Record.
13. Remove the red tube (only) and replace with the orange tube. Record.
14. Continue inserting colored tubes into the purple tube in the same sequence (yellow, green, blue) as

directed above but only until the dose calibrator display is 10 uCi or as low as is required by your
regulatory agency. Record each display as you proceed.
15. Remove the Calicheck assembly and place source in a shielded container. Place Calicheck in
storage container provided.

NOTE

For each measurement, use the tube(s) with the
color band up.

2-2

2Operation

Data Treatment of Data Sheet #1

2.3 Data Treatment of Data Sheet #1

1. Divide the numerator by the denominator in Column B to determine the Calibration Factor, and
record in Column C. Retain these values for future reference. These factors will be used for all
future activity linearity tests provided all conditions of the test are met (i.e., same dose calibrator,
same kit, same radionuclide, same source configuration, the same limits for Mo-99 contamination).

2. Compare results to chart of "Calibration Factor Examples" below. Differing values may be due to
variations in geometry, in the response of the dose calibrator and/or in the kit manufacturing
process itself.

3. Transfer determined Calibration Factors from Data Sheet #1 to appropriate place in Column C of
Data Sheet #2. (See example on page 3-4.) To confirm the accuracy of the determined factors,
complete Data Sheet #2. If no error has been made, all values in Column D (product of B x C)
should be the same. If values differ, repeat the determination.

Example
To determine the calibration factors for a Brand X dose calibrator, a source of TC-99m was prepared. The
source read 831 mCi in the black tube and generated the following data. All readings were taken at lowest
range setting possible and converted to mCi units.

Tubes Readings Calibration Factor
A B C

Black Only = 831 mCi = 1.00
Black Only = 831 mCi =

Black Only = 831 mCi = 3.31
Black & Red = 251 mCi =

Black = 831 mCi = 12.4
Only
=
Black & Orange = 67.0 mci
=
Black Only = 831 mCi = 38.1
Black & Yellow = 21.8 mCi 136
= 411
Black Only = 831 mCi = 704
Black & Green = 6.11 mCi 1310
= 3060
Black Only = 831 mCi = 9990
Black & Blue = 2.02 mCi 32500
= 134000**
Black Only = 831 mCi =
Black & Purple = 1.18 mCi
=
Black Only = 831 mCi =
Black/Purple/Red = .635 mCi
=
Black Only = 831 mCi =
Black/Purple/Orange = .272 mCi
=
Black Only = 831 mCi =
Black/Purple/Yellow = .0832 mCi
=
Black Only = 831 mCi =
Black/Purple/Green = .0256 mCi
=
Black Only = 831 mCi =
Black/Purple/Blue = .0062 mCi

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Operators Manual

* Read as 63S uCi and converted to .635 mCi. Similarly 83.2 uCi has been converted to .0832 mCi and 6.2 uCi would be
converted to 006.2 mCi.
* Doubtful calibration factor because the dose calibrator display was only 6.2 uCi. A source larger than 831 mCi is necessary in

order to calibrate this combination of tubes.

2-4

2Operation

Data treatment of Data Sheet #1

Data Sheet #1 *

Kit Calibration

Dose S/N Date
Calibrator

All reading must be taken at lowest setting available and converted to mCi units.

Tubes = Displayed = Calibration
A = Activity = Factor
mCi 1.00
Black Only = mCi =
Black Only = =
mCi
Black Only = mCi =
Black & Red = =
mCi
Black Only = mci =
Black & Orange = =
mCi
Black Only = mCi =
Black & Yellow = =
mCi
Black Only = mCi =
Black & Green = =
mCi
Black Only = mCi =
Black & Blue = =
mCi
Black Only = mCi =
Black & Purple = =
mCi
Black Only = mCi =
Black/Purple/Red = =
mCi
Black Only = mCi =
Black/Purple/Orange = =
mCi
Black Only = mCi =
Black/Purple/Yellow = =
mCi
Black Only = mCi =
Black/Purple/Green = =
mCi
Black Only mCi
Black/Purple/Blue

Source Configuration ml Syringe
ml Vial
ml in
a
ml in
a

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Nuclear Associates 34-210
Operators Manual

* To be completed once, or following repair of dose calibrator or Calicheck Kit. In all instances these factors of activity linearity by
standard techniques. Keep this form for future reference.

2-6

3Activity Linearity Procedure
Activity Linearity Procedure

Section 3

Activity Linearity Procedure

3.1 Activity Linearity Procedure

To determine if a dose calibrator can respond linearly to a variety of levels of radioactivity via the
Calicheck Technique.

3.2 Preparation

Same as described in Section 2.1, Calibration of Calicheck. Use the same source configuration as used in
that calibration procedure.

3.3 Procedure

1. Remove any syringe hanger or chamber liner, if necessary, from dose calibrator.
2. Set dose calibrator to measure Tc-99m.
3. Adjust zero, background, etc., if applicable. Check zero on each range. If background is not "zero"

on all ranges, zero on one range and record values on all other ranges to add or subtract from final
results when those ranges are used.
4. Place source to be used for the activity linearity procedure into the black tube and insert tube into
the dosecalibrator CAREFULLY with the open end in the upward position.
5. Record "displayed activity" on "Black Only" on Data Sheet #2 "Dose Calibrator Activity Linearity
Check", (see page 3-4).

NOTE
Carefully ensure that, in the following steps 6
through 10, each tube is firmly seated against the
lead at the base of the black tube.
6. Place red tube in the dose calibrator over the black tube. Record "displayed activity" on "Black &
Red" blank on Data Sheet #2.
7. Replace red tube with orange tube. Record on "Black & Orange" blank.
8. Replace orange tube with yellow tube. Record on "Black & Yellow" blank.
9. Replace yellow tube with green tube. Record on "Black & Green" blank.
10. Replace green tube with blue tube. Record on "Black & Blue" blank.

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Nuclear Associates 34-210
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NOTE

Carefully ensure that, in the following steps 11
through 14, the purple-banded tube is placed over
the black center tube and lowered all the way down
over the lead ring and gray plastic pedestal forming
the base of the source holding tube. The other
color-banded tubes, when added, are designed to
be inserted between the black center tube and the
outer purple-banded tube.

11. Replace blue tube with purple tube. Record on "Black & Purple blank.
12. Leaving the purple tube in place, install the red tube over the black tube and lower it inside the

purple tube. Record display on the "Black & Purple/Red" blank.
13. Remove the red tube (only) and replace with the orange tube. Record on "Black & Purple/Orange"

blank.
14. Remove the orange tube and continue with the yellow tube followed by the green and blue tuber, if

necessary. In each case record the displays in the appropriate blank on Data Sheet #2.

NOTE

When performing linearity testing, up to twelve
readings will be available providing twelve
attenuation calibration factors have been
predetermined. The tube combination (black center
with purple and blue shielded tubes in place)
offering the most attenuation will reduce a several
curie display to approximately 10 uCi or less. Use
only as many tubes and combination of tubes
needed to reduce your dose calibrator display to
the lowest level required by your regulatory agency.

15. Remove Calicheck assembly and place source in shielded container.

3.2 Data Treatment of Data Sheet #2

NOTE

To be completed each calendar quarter or at a
frequency required by your license conditions.

1. Enter appropriate Calibration Factors from Data Sheet #1 for your dose calibrator in Column C of
Data Sheet #2.

2. Multiply the value in Column B by the corresponding value in Column C to determine product of
each entry for Column D. Record values. (Ideally, these values will all be the same.)

3. Add all products in Column D and divide by the number of entries in Column D to determine the
mean value. Multiply the mean by 1.05 and 0.95 as indicated. These define the upper and lower
limits of ± 5% variation.

3-2

3Activity Linearity Procedure

Data Treatment of Data Sheet #2

If all values in Column D fall between these two limits, your dose calibrator has acceptable activity
linearity. The test is complete, unless additional readings are required to expand the range of activities
displayed. If so, continue the test by preparing an aliquot containing about 100 times more activity than
the displayed activity in the last measurement. The test is then repeated (Data Sheet #2 only), using the
same source configuration as that used in determining the calibration factors on Data Sheet #1.

If any values in Column D fall outside the limits, repeat the study to rule out possible variations in the
initial data. Consistent results that are outside the limits indicate that the instrument is exhibiting non-
linearity. Corrective act is indicated.

Example

A Mo/Tc generator is eluted and yields 1342 mCi. The entire elution is placed in the dose calibrator inside
the black tube. Subsequent readings generated the following data. All readings were taken at lowest
range setting possible and converted to mCi units.

A B x C D
Tube Color Displayed x Calibration Product of B x
x
Black Only Activity x Factor C
Black & Red x
Black & Orange 1342 mCi x 1.00 = 1342
Black & Yellow 407 mCi x 3.31 = 1347
Black & Green 107 mCi x 12.4 = 1327
Black & Blue 36.2 mCi x 38.1 = 1379
Black & Purple 9.84 mCi x 136 = 1338
Black & Purple & Red 3.28 mCi x 411 = 1348
Black & Purple & Orange 1.90 mCi x 704 = 1338
Black & Purple & Yellow 1.03 mCi 1310 = 1349
Black & Purple & Green .436 mCi 3060 = 1334
Black & Purple & Blue .136 mCi 9990 = 1359
32500 = 1375
.0423 mCi 134000 = 1461
.0109 mCi
16297

Mean x 1.05 = 1426 = Upper Limit
Mean x 0.95 = 1290 = Lower Limit

The reading for the Black & Purple & Blue tube combination is outside the limits. The procedure should be
repeated to confirm the data. Repair may be indicated. Failure to account for a re-zoning problem
between ranges (see Procedure, Step #3 in Section 3.1) or an unstable background may also have
produced this apparent non-linearity

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Nuclear Associates 34-210
Operators Manual

Data Sheet #2 (To be completed each quarter)

Dose Calibrator Activity Linearity Check

Facility Date RSO
Dose Calibrator & Calicheck Serial
Model No.
Dose Calibrator Serial Performed
No. By
Source Reviewed
Configuration* By

All readings must be taken at the lowest range setting available and converted to mCi units.

A** B** C*** D
Tube Color Displayed Calibration Product of B x

Black Only Activity Factor C
Black & Red
Black & Orange mCi x =
Black & Yellow mCi x =
Black & Green mCi x =
Black & Blue mCi x =
Black & Purple mCi x =
Black & Purple & Red mCi x =
Black & Purple & Orange mCi x =
Black & Purple & Yellow mCi x =
Black & Purple & Green mCi x =
Black & Purple & Blue mCi x =
mCi x =
mCi x =

Sum

Sum (From Column D) x 1.05 = = Upper Limit
= x 0.95 = = Lower Limit

No. Entries (From Column B)

NOTE

Compare Column D data to upper and lower limits
to confirm linearity.

* The source configuration to be used must be that which was used when the calibration factors in Column C were determined.
** Continue testing in sequence shown until the display is reduced to your minimum patient dose. 10 uCi or less, or as your

regulatory agency requires. Use the number of entries in Column B in calculating the upper and low limits.
*** The calibration factors for this column are specific to your dose calibrator ad the source geometry used when determined.

They can be found on Data Sheet # 1 in your Calicheck Kit instruction manual.

3-4

3Activity Linearity Procedure

Data Treatment of Data Sheet #2

Dose Calibrator Activity Linearity Check

Facility Date RSO
Dose Calibrator & Calicheck Serial
Model No.
Dose Calibrator Serial Performed
No. By
Source Reviewed
Configuration* By

All readings must be taken at the lowest range setting available and converted to mCi units.

A** B** C*** D
Tube Color Displayed Calibration Product of B x

Black Only Activity Factor C
Black & Red
Black & Orange mCi x =
Black & Yellow mCi x =
Black & Green mCi x =
Black & Blue mCi x =
Black & Purple mCi x =
Black & Purple & Red mCi x =
Black & Purple & Orange mCi x =
Black & Purple & Yellow mCi x =
Black & Purple & Green mCi x =
Black & Purple & Blue mCi x =
mCi x =
mCi x =

Sum

Sum (From Column D) x 1.05 = = Upper Limit
= x 0.95 = = Lower Limit

No. Entries (From Column B)

NOTE

Compare Column D data to upper and lower limits
to confirm linearity.

* The source configuration to be used must be that which was used when the calibration factors in Column C were determined.
** Continue testing in sequence shown until the display is reduced to your minimum patient dose. 10 uCi or less, or as your

regulatory agency requires. Use the number of entries in Column B in calculating the upper and low limits.
*** The calibration factors for this column are specific to your dose calibrator ad the source geometry used when determined.

They can be found on Data Sheet # 1 in your Calicheck Kit instruction manual.

3-5

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139
440.498.2564

www.flukebiomedical.com/rms