DOSAGE AND ADMINISTRATION
Bone And Cardiac Imaging
The recommended adult doses of Technetium Tc 99m
Pyrophosphate Injection are:
Indication |
Doses as Technetium Tc 99 |
Fraction of Vial Contents Required |
Skeletal Imaging |
185 to 555 megabecquerels (5 to 15 mCi) |
0.07 to 0.91 |
Cardiac Imaging |
370 to 555 megabecquerels (10 to 15 mCi) |
0.26 to 0.45 |
Technetium Tc 99m Pyrophosphate
Injection is injected intravenously over a 10-to 20-second period. For optimal
results, bone imaging should be done one to six hours following administration.
Cardiac imaging should be done 60 to 90 minutes following administration. The
acute myocardial infarct can be visualized from 24 hours to nine days following
onset of symptoms, with maximum localization at 48 to 72 hours. Cardiac imaging
should be done with a gamma scintillation camera. It is recommended that images
be made of the anterior, left anterior oblique and left lateral projections.
The patient dose should be
measured by a suitable radioactivity calibration system immediately prior to
administration. It is also recommended that the radiochemical purity be checked
prior to administration.
Blood Pool Imaging
The recommended adult dose of Technescan PYP is one-third
(0.33) to the entire vial contents, followed by 555 to 740 megabecquerels (15
to 20 millicuries) of sodium pertechnetate Tc 99m. Cardiac imaging should be
done 10 minutes following the administration of sodium pertechnetate Tc 99m (in
vivo method) or Tc 99m labeled red blood cells (modified in vivo/in vitro
method) utilizing a scintillation camera interfaced to an electrocardiographic
gating device.
In Vivo Method
Technescan PYP is reconstituted with sterile,
non-pyrogenic normal saline containing no preservatives. The patient dose is
administered intravenously 15 to 30 minutes prior to the intravenous
administration of 555 to 740 megabecquerels (15 to 20 millicuries) of sodium
pertechnetate Tc 99m. Technescan PYP should be injected by direct venipuncture.
Heparinized catheter systems should be avoided.
Modified In Vivo/In Vitro Method Using
Acid-Citrate-Dextrose (ACD): Technescan PYP is reconstituted with sterile,
non-pyrogenic normal saline containing no preservatives, and the patient dose
is administered intravenously. An intravenous line containing a 3-way stopcock
is inserted in a large peripheral vein and kept patent with a continuous drip
of sterile, non-pyrogenic normal saline containing no preservatives. Thirty
minutes after Technescan PYP injection, the infusion line and stopcock are
cleared by withdrawing and discarding approximately 5 milliliters of whole
blood. Immediately following, approximately 5 milliliters of whole blood are
withdrawn into a syringe containing 1 milliliter preservative-free
acid-citrate-dextrose (ACD) and 555 to 740 megabecquerels (15 to 20
millicuries) of sodium pertechnetate Tc 99m. The stopcock is then turned,
residual blood is flushed from the intravenous line, and the normal saline flow
is readjusted. The syringe is gently rotated to mix and allowed to incubate at
room temperature for 10 minutes prior to injection via the 3-way stopcock.
Modified In Vivo/In Vitro Method Using Heparin:
Technescan PYP is reconstituted with sterile, non-pyrogenic normal saline
containing no preservatives, and the patient dose is administered
intravenously. An infusion set fitted with a 3-way stopcock is placed in a
large peripheral vein, and the intravenous line is heparinized with a saline
solution containing 5 to 10 units preservative-free heparin per milliliter.
Thirty minutes after Technescan PYP injection, 3 milliliters of blood are
withdrawn into a syringe containing 555 to 740 megabecquerels (15 to 20
millicuries) of sodium pertechnetate Tc 99m. Anticoagulation of the blood is
provided by residual heparin in the intravenous line. The syringe is gently
rotated to mix and allowed to incubate at room temperature for 10 minutes prior
to injection via the 3-way stopcock.
Parenteral drug products should be visually inspected for
particulate matter and discoloration prior to administration whenever solution
and container permit. Do not use if contents are turbid.
Radiation Dosimetry
Method Of Calculation
The following radiation absorbed dose values were
obtained using the Medical Internal Radiation Dose Committee (MIRD) Schema.
Bone And Cardiac Imaging
Maximum Dose
555 megabecquerels (15 millicuries) administered
intravenously. The effective half-life was assumed to be the physical half-life
for all calculated values. About 50% of each dose of Technetium Tc 99m
Pyrophosphate Injection is retained in skeleton, and about 50% is excreted into
the bladder. The estimated absorbed radiation doses to an average patient (70
kg) from an intravenous injection of a maximum dose of 555 megabecquerels (15
millicuries) of Technetium Tc 99m Pyrophosphate Injection are shown in Table 4.
Table 4: Absorbed Radiation Doses (Bone and Cardiac
Imaging)
Tissue |
Technetium Tc 99m Pyrophosphate Injection |
mGy/555 MBq |
rads/15 mCi |
Skeleton* |
5.9 |
0.59 |
Bone Marrow |
4.2 |
0.42 |
Kidneys |
21.0 |
2.10 |
Total Body |
1.3 |
0.13 |
Bladder |
2-hr. void |
14.6 |
1.46 |
4.8-hr. void |
34.5 |
3.45 |
Testes |
2-hr. void |
1.5 |
0.15 |
4.8-hr. void |
2.3 |
0.23 |
Ovaries |
2-hr. void |
1.4 |
0.14 |
4.8-hr. void |
2.3 |
0.23 |
Heart |
Normal |
1.1 |
0.11 |
Impaired |
2.2 |
0.22 |
*Dose at point of highest
uptake may be a factor of 10 higher. |
Blood Pool Imaging
The estimated absorbed radiation doses to an average
patient (70 kg) from administration of 740 megabecquerels (20 millicuries) of
sodium pertechnetate Tc 99m, 30 minutes after the intravenous administration of
Technescan PYP are shown in Table 5.
Table 5: Absorbed Radiation Doses2
(Blood Pool Imaging)*
Tissue |
Sodium Pertechnetate Tc 99m 30 min. Post Technescan PYP Administration |
mGy/740 MBq |
rads/20 mCi |
Bladder Wall |
6.8 |
0.68 |
Ovaries |
4.6 |
0.46 |
Testes |
2.6 |
0.26 |
Red Marrow |
3.8 |
0.38 |
Spleen** |
3.0 |
0.30 |
Blood |
10.2 |
1.02 |
Total Body |
3.0 |
0.30 |
*Assumes non-resting state,
with 75% of the sodium pertechnetate Tc 99m labeling red blood cells and the
other 25% remaining as pertechnetate.
**Assumes no initial uptake in spleen. |
HOW SUPPLIED
Catalog Number 094.
Technescan PYP is supplied as a lyophilized powder
packaged in vials. Each vial contains 11.9 mg sodium pyrophosphate, 3.2 mg
(minimum) stannous chloride (SnCl2•2H2O) and 4.4
milligrams (maximum) total tin expressed as stannous chloride (SnCl2•2H2O),
sealed under an atmosphere of nitrogen. Prior to lyophilization the pH is
adjusted with hydrochloric acid. The pH of the reconstituted drug is between
4.5 and 7.5.
Kit containing 5 vials is available.
Storage
The Technescan PYP Kit must be maintained in a
refrigerator, 2° to 8°C (36° to 46°F) until use. The reconstituted vial should
be stored at controlled room temperature, 20° to 25°C (68° to 77°F).
Instructions For Preparing The Drug
Procedural Precautions
All transfer and vial stopper entries must be done using
aseptic techniques.
Procedure
Bone And Cardiac Imaging
Note 1: Wear waterproof gloves during the entire
preparation procedure and during subsequent patient dose withdrawals from the
reaction vial.
Note 2: Make all transfers of sodium pertechnetate
Tc 99m solution during the preparation procedure with an adequately shielded
syringe.
Note 3: Keep the Radioactive Preparation in the
lead shield described below (with cap in place) during the useful life of the Radioactive
Preparation. Make all withdrawals and injections of the Radioactive Preparation
with an adequately shielded syringe.
- A Technescan PYP reaction vial is removed from the
refrigerator and approximately five (5) minutes are allowed for the contents to
come to room temperature.
- Attach radioassay information label with radiation
warning symbol to the reaction vial and place the vial in a lead Dispensing
Shield fitted with a lead cap and having a minimum wall thickness of 1/8 inch.
Do not remove reaction vial from the Dispensing Shield except, temporarily, for
Step 5 below.
- Sodium pertechnetate Tc 99m solution (1 to 10
milliliters) is added to the reaction vial. In choosing the amount of
technetium Tc 99m radioactivity to be used in the preparation of the Technetium
Tc 99m Pyrophosphate Injection, the labeling efficiency, number of patients,
administered radioactive dose, and radioactive decay must be taken into
account. The recommended maximum amount of technetium Tc 99m to be added to the
reaction vial is 3.7 gigabecquerels (100 millicuries).
- With the reaction vial in the Dispensing Shield (with cap
in place), shake sufficiently to bring the lyophilized material into solution.
Allow to stand for five (5) minutes at room temperature.
- Using proper shielding, the reaction vial should be
visually inspected. The resulting solution should be clear and free of
particulate matter. If not, the reaction vial should not be used.
- Assay the product in a suitable calibrator and record the
time, date of preparation and the activity of the Technetium Tc 99m
Pyrophosphate Injection onto the radioassay information label. Store the
reaction vial in the Dispensing Shield at 15 ° to 30°C when not in use and discard
after six (6) hours from the time of preparation.
Blood Pool Imaging
- A Technescan PYP reaction vial is removed from the
refrigerator and approximately five (5) minutes are allowed for the contents to
come to room temperature.
- Reconstitute the reaction vial with 3 milliliters of
sterile, non-pyrogenic normal saline containing no preservatives.
- Shake the reaction vial sufficiently to bring the
lyophilized material into solution. Allow to stand for five (5) minutes at room
temperature.
- The reaction vial should be visually inspected. The
resulting solution should be clear and free of particulate matter. If not, the
reaction vial should not be used.
- Store reconstituted reaction vial at 15° to 30°C when not
in use and discard after six (6) hours from time of preparation.
This reagent kit is approved for distribution to persons
licensed by the U.S. Nuclear Regulatory Commission to use byproduct material
identified in Section 35.200 or under an equivalent license of an Agreement
State.
REFERENCES
2Data supplied by Oak Ridge Associated
Universities, Radiopharmaceutical Internal Dose Information Center, 1986.
Manufactured by: Mallinckrodt Nuclear Medicine LLC
Maryland Heights, MO 63043. Revised: Jun 2016