A simple and effective technique to reduce staff exposure during the preparation of radiopharmaceuticals

In the preparation of radiopharmaceuticals, staff receive considerable radiation exposure to the hands during withdrawal of activity from the elution vial, from a combination of the syringe and elution vial activities. In an attempt to reduce the radiation burden to the hands, a simple technique was developed that utilizes a modified lead pot lid and a syringe bearing a long needle with a sterile needle guide.

An elution vial in a lead pot with an attached syringe was secured at an angle of 45 degrees, simulating the action of withdrawing (99m)Tc-pertechnetate from the elution vial. The (99m)Tc activity ratio of vial to syringe was 20:1. A gamma- camera detector without collimator was positioned at the syringe plunger and count profiles were obtained after 10 min of data acquisition. The experiment was repeated using the same set-up with (a) the modified lid on the lead pot and (b) a cold syringe to determine the contribution of the radioactive syringe to the count profile. Each experiment was repeated at the vertical position, simulating the normal action of redispensing (99m)Tc activity into the elution vial.

The modified lid reduced exposure from the elution vial, with a count reduction of >98% for both orientations. The contributions of vial radioactivity to the total count profile were 76% and 84% for vertical and 45 degrees orientations, respectively. The contributions of syringe activity were 24% and 16% for vertical and 45 degrees orientations, respectively.

A reduction in the photon flux to the hands of up to 84% (with an associated reduction in hand dose) can be achieved by withdrawing activity through a modified lid on the lead pot housing the elution vial, without significantly altering normal work practices.