Plaques which use removable I-125 sources such as the COMS, ROPES, and USC plaques must be assembled on-site just prior to use. The isotope in BEBIG Ru-106 plaques is not removable so no local assembly is required.

Plaques are assembled on-site in the hospital hot lab behind an L block.

The radioactive sources (or "seeds") are removed from the shipping vial. A cardboard bowl is placed under the plaque to prevent losing the tiny seeds. The seeds are handled using a long forceps. A "third hand" device holds the plaque by one of its suture eyelets.

The seeds are simply dropped into the slots of a USC plaque according to the treatment plan and loading diagram.

A drop of cyanoacrylate adhesive is used to glue the seeds into the slots of a USC plaque. It helps if the cyanoacrylate has a purple dye added to it so you can be sure each seed is covered. Use just enough glue to barely surround each seed, the less cyanoacrylate used the better! To remove the seeds, the plaque is soaked in acetone for a few minutes to disolve the glue.