Cows in the Pharm

For the past couple weeks, I have been milking the cows, a.k.a generators on 3rd runs and 5th runs.  3rd run occurs around 0730hrs and 5th runs are around 1200hrs.  For the sake of speaking in correct nuclear terms, from this point on, I will be writing in military times.

The Generators and me

The generators are shielded inside these shields, so you cannot see them and that is for our protection.  And no, I am not wearing a space suit:)  In the compounding area, a.k.a buffer area, I have to gown up into a buffer coat (clean lab coat), booties for my shoes, hair net, disposable sleeves (in case we get our arms "hot"), and disposable hand gloves.  In case I get myself contaminated, I can just dispose items and set the lab coat in the decay room.  Once your lab coat or sometimes, pants are contaminated, you have to let it decay.  Depending on the isotope you were working with, it may take weeks for you to get your personal belonging back from the decal room.

These generators will produce the isotope Tc-99m, main juice of nuclear imaging drugs.  Items needed to milk a generator are: an empty 10mL or 20mL- drug vial, one elution shield, and one vial of saline solution (volume varies).  Milking the generator is the same as eluting and/or hitting.  I can say, "I am going to hit/elute/milk the generator."  After I elute the generator, I will proceed over to a callibrator to measure my Mo-99 breakthrough and assay how much Tc-99m activity I have required.

From left: elution shield, 10mL normal saline, evacuated 10mL vial, 10cc syringe

After you hit the generator, run away for a few seconds because it's HOT!!!

Carefully remove elution shield and replace shielded TechneStat vial.  Now, before using the activity I get, I need to determine the techneium Tc-99m concentration and molybdenum Mo-99 content.  Molybdenum Mo-99 breakthrough acceptable limit is 0.15 kilobecquerel molybdenum Mo-oo per megabacquerel technetium Tc-99m (0.15 microcurie Mo-00 per miliucurie Tc-99m) per administered dose in the injection, at time of administration. To determine that, I use the calibrator.

Calibrator- assays activity of individual isotopes

Step 1: using calibrator, press "Mo Assay" button, get background activity with this empty canister

Step 2: Open the elusion shield and place the evac vial with the activity in the canister, cap canister

Then, you assay the canister with the activity instead for Mo-99 breakthrough.  Next, take activity out of canister and measure the amount of technetium Tc-99m you have eluted.  Recently, I have assayed activity anywhere from 240 milicuries (mCi) to 3,000mCi.

Now, the technetium is used to compound different drug kids depending need for different imaging purposes ie bone imaging, gastric-intestinal studies, lung-ventilation studies, heart scans, etc.  Technetium has a half life (t_½) of 6.01 hours; it is the amount of time for technetium activity to decay its activity by half. Tc-99m has a wide variety of use and I will share more later on:)

There's technetium on the periodic table! 

I absolutely LOVE that all that chemistry and organic chemistry lectures from high school to graduate school have come to good use!  Not to mention, I love that I get to use many of the transition metals-- remember how they were really not mentioned as much as the halogens or inert gases? Try guessing the isotope Y!  This totally intrigues me...another reason why I love nuclear pharmacy!

I am thrilled that I will be starting my authorized user training course on Monday, January 9th, 2012. Good luck to me-- more studying to do for a couple more months!

Until next time!
Sarah


Photographs: Courtesy of Sarah and Gordy