Radiolabel Blood Components

Subgroup III: Pharmaceutical and Radiopharmaceutical Agents

required lab equipment and supplies

• PPE

• sterile supplies (conical centrifuge tubes with screw caps, plastic syringes, needles)

• ring stand and clamps

• centrifuge

anticoagulant and other additives

• acid citrate dextrose (ACD) or heparin

• hetastarch

• cold stannous PYP

What do you use for cell washing?

sodium chloride (0.9%) injection, USP

What radiopharmaceuticals can be used to label RBC’s?

Tc99m pertechnetate, Tc99m HMPAO, In-111 oxyquinoline

in vivo labeling efficiency

85% (lowest)

modified in vivo labeling efficiency

90%

in vitro labeling efficiency

95% (highest)

in vivo steps

1. inject “cold” stannous pyrophosphate (15 ug/kg)

2. wait for 20-30 minutes for circulation

3. inject 20-30 mCi Tc99m pertechnetate into a different vein, preferably the other arm

modified in vivo steps

1. inject “cold” stannous pyrophosphate (15 ug/kg)

2. wait for 20-30 minutes for circulation

3. use an 18-20 gauge needle to draw 3-5 mL of blood

4. mix the RBC’s with 20-30 mCi of Tc99m pertechnetate and an anticoagulant

   1. heparin at 10-15 U/mL blood

   2. ACD at 0.15 mL/mL blood

5. incubate for 10 minutes with occasional gentle mixing

6. reinject the mixed RBC’s into patient

in vitro steps

1. use an 18-20 gauge needle to draw 3-5 mL of blood into a syringe containing an anticoagulant

   1. heparin at 10-15 U/mL blood

   2. ACD at 0.15 mL/mL blood

2. follow UltraTag instructions for labeling

3. reinject mixed RBC’s into patient

in vivo pros

easiest, no risk of injecting the wrong patient’s blood

in vivo cons

lowest labeling efficiency

in vitro pros

highest labeling efficiency

in vitro cons

risk of administering wrong blood, most difficult procedure

equation for calculation of labeling efficiency

% RBC Labeling = [(Activity RBC) / (Activity RBC + Activity Plasma)] *100

What must you verify upon reinjection of RBC’s?

two forms of ID (patient ID, blood band, Typenex barcode)