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 is used to stabilize the carrier while inserting seeds.

The seeds are inserted into the slots in the silicone carrier of a COMS plaque as illustrated, according to the treatment plan and loading diagram.

We have found that glue is not absolutely necessary with COMS plaques if the sources are secure in the carrier. However, we like to place a drop of cyanoacrylate adhesive on the seeds once they are secure in the slot. The cyanoacylate does not adhere to the silicone carrier, it just gives a "tackier" surface to the seeds. 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 glue from the seeds, the plaque and carrier are soaked in acetone for a few minutes to disolve the glue.

When all the seeds are in place, the gold shell is placed over the plaque with its suture eyelets oriented according to the loading diagram. The example below illustrates the different appearance of slots with seeds installed and those that are empty.