Technetium Tc 99m-labeled red blood cells are used for blood pool imaging, including cardiac first pass and gated equilibrium imaging and for detection of sites of gastrointestinal bleeding.
DOSAGE AND ADMINISTRATION
The Instructions for Preparation must be carefully followed for preparing technetium Tc 99m-labeled red blood cells using Ultratag™ RBC.
The suggested dose range of technetium Tc 99m-labeled red blood cells in the average patient (70 kg) is 370 MBq (10 mCi) to 740 MBq (20 mCi).
The patient dose should be measured by a suitable radioactivity calibration system immediately prior to administration.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Aseptic procedures and a shielded syringe should be employed in preparing and withdrawing doses for administration to patients.
The user should wear waterproof gloves during the administration procedure.
The estimated radiation doses to an average adult (70 Kg) from an intravenous injection of a maximum dose of 740 MBq (20 mCi) of technetium Tc 99m-labeled red blood cells are shown in Table 4.
These radiation absorbed dose values were calculated using the Medical Internal Radiation Dose (MIRD) Committee Schema.
Table 4: Absorbed Radiation Dose Estimates2 For Ultratag™ RBC Technetium Tc 99m Labeled Red Blood Cells*
|Organ||mGy/740 MBq||rads/20 mCi|
|* Assumes non-resting state and biological half-life for all organs and whole body of 63.7 hours. The peak percent dose for heart chambers is 15.5%, for liver is 5.57%, spleen is 4.07% and for remainder of body is 74.8%. Assumes patient voids at 2.0 hour intervals.|
2Dose estimates based on Phase I human biodistribution data generated at Brookhaven National Laboratories. Dose estimates were calculated at Oak Ridge Associated Universities, Oak Ridge, Tennessee.
Catalog Number 068.
Ultratag™ RBC consists of three separate nonradioactive components:
1. A 10 milliliter reaction vial containing:
Stannous Chloride, Dihydrate (SnCl2 •2H2O) â€“ 50 ug minimum
Stannous Chloride, Dihydrate (SnCl2 •2H2O) â€“ 96 ug theoretical
Tin Chloride (Stannous and Stannic), Dihydrate (as SnCl2 •2H2O) â€“ 105 ug maximum
Sodium Citrate, Dihydrate â€“ 3.67 mg
Dextrose, Anhydrous â€“ 5.50 mg
Prior to lyophilization, the pH is adjusted to 7.1 to 7.2 with sodium hydroxide. The contents of the vial are lyophilized and stored under argon.
2. Syringe I contains:
Sodium Hypochlorite â€“ 0.6 mg in Sterile Water for Injection
The total volume of this syringe is 0.6 mL. Sodium hydroxide may have been added for pH adjustment. The pH of this solution is 11 to 13. The syringe must be protected from light to prevent degradation of the light-sensitive sodium hypochlorite.
3. Syringe II contains:
Citric Acid, Monohydrate â€“ 8.7 mg
Sodium Citrate, Dihydrate â€“ 32.5 mg
Dextrose, Anhydrous â€“ 12.0 mg in Sterile Water for Injection
The total volume of this syringe is 1.0 mL. The pH range of this solution is adjusted to 4.5 to 5.5 with sodium citrate or citric acid.
The kit should be stored at controlled room temperature 20° to 25°C (68° to 77°F). Syringe I should be protected from light if not stored in the kit tray.
Instructions for the Preparation of Technetium Tc 99m-Labeled Red Blood Cells Using Ultratag™ RBC
- Collect patient's blood sample (1.0 to 3.0 mL) using heparin or ACD as an anticoagulant. The amount of ACD should not exceed 0.15 mL of ACD per mL of blood. The recommended amount of heparin is 10-15 units per mL of blood. DO NOT USE EDTA OR OXALATE AS AN ANTICOAGULANT.
- Using a large-bore (19 to 21 gauge) needle, transfer 1.0 to 3.0 mL of anticoagulated whole blood to the reaction vial and gently mix to dissolve the lyophilized material. Allow to react for five minutes.
- Add contents of Syringe I, mix by gently inverting four to five times.
- Add the contents of Syringe II to the reaction vial. Mix by gently inverting four to five times.
- Place the vial in a lead shield fitted with a lead cap and having a minimum wall thickness of 1/8 inch. Add 370 to 3700 MBq (10 to 100 mCi) sodium pertechnetate Tc 99m (in a volume of up to 3 mL) to the reaction vial. The avoidance of long technetium Tc 99 in-growth times and the use of fresh sodium pertechnetate Tc 99m generator eluate is recommended.
- Mix by gently inverting reaction vial four to five times. Allow to react for 20 minutes with occasional mixing.
- Technetium Tc 99m-labeled red blood cells should be injected within 30 minutes of preparation or as soon as possible thereafter.
- If desired, assay labeling efficiency immediately prior to injection. Typical labeling efficiency is greater than 95%.
- Mix gently prior to withdrawal of patient dose. Aseptically transfer the technetium Tc 99m-labeled red blood cells to a syringe for administration to the patient. Use largest bore needle compatible with patient administration to prevent hemolysis.
- Assay the Tc 99m-labeled red blood cell patient dose in a suitable calibrator and complete the radioassay information label. Affix the radioassay information label to the shield.
- The kit does not contain an anticoagulant. Therefore, a syringe or vacutainer™ tube treated with ACD or heparin must be used for drawing the patient's blood. The amount of ACD should not exceed 0.15 mL of ACD per mL of blood. The recommended amount of heparin is 10-15 units per mL of blood. Improperly anticoagulated blood will be unsuitable for reinjection.
- If desired, the labeling yield determination can be carried out as follows:
Transfer 0.2 mL of the technetium Tc99m labeled red blood cells to a centrifuge tube containing 2 mL of 0.9% NaCl. Centrifuge for five minutes and carefully pipet off the diluted plasma. Measure the radioactivity in the plasma and red blood cells separately in a suitable counter. Calculate labeling efficiency as follows:
% RBC Labeling = Activity RBC/ Activity RBC + Activity Plasma X 100
This reagent kit is approved for distribution to persons licensed by the U.S. Nuclear Regulatory Commission to use byproduct material identified in Section 10 CFR 35.200 or under an equivalent license of an Agreement state.
Manufactured by: Curium US LLC, Maryland Heights, MO 63043. Revised: Dec 2018