DMSA Dosage

Preparation of Technetium Tc 99m DMSA is done by the following aseptic procedure:

1. Waterproof gloves should be worn during the preparation
2. Snap off the plastic lid and place room temperature reaction vial in an appropriate lead shield.
3. Swab the rubber closure of the vial with a germicide
4. Inject as close to 1 cc as possible of sterile additive free sodium pertechnetate Tc 99m injection containing up to 1480 MBq (40 mCi) into the vial freshly eluded within 2 hours from a technetium generator. Be sure to maintain inert atmosphere in vial by introducing as little air as possible during reconstitution. NOTE: If sodium pertechnetate Tc 99m injection must be diluted, use only Low Dissolved Oxygen (LDO)
5. Secure the lead shield cover. Swirl the vial gently to mix contents and let stand for 15 minutes. Add 1 ml Acetate buffer at this time. (This will interfere with the tagging process if introduced any earlier). Buffer must be added (May be added up to 1 hour after Tc 99m)
6. Examine vial contents; if the solution is not clear and free of particulate matter and discoloration on visual inspection, it should not be used
7. Measure the radioactivity by a suitable calibration system and record prior to patient administration
8. Buffered material should be used within 2 hours
9. Appropriate quality control is recommended

Tagging Tips

• If you need only a one or two mCi dose for your patient, use about 10 mCi of Tc 99m for your kit. Do not stretch your kit to 40 mCi if you do not need to. We have tested the kits to 40 mCi with a Friday generator eluted on Monday but recommend using only what you need
• Keep your volumes low. Take your Tc 99m and dilute to about 1cc with the Low Dissolved Oxygen saline and inject into the DMSA kit
• Let the kit stand for about 15 minutes with just the Tc 99m and DMSA (NO BUFFER)
• After 15 minutes, then add the buffer. This is only for patient comfort and will interfere with the tagging process if introduced any earlier
• After buffering you can add additional “Low Dissolved Oxygen” saline to dilute the kit
• You should inject the dose within 2 hours after making the kit for best results