Wednesday, February 15, 2012

Art of Making I-131 Capsules

I started training and making radioiodine capsules few weeks ago. I-131 capsules, to be exact. Well, my colleague TJ trained me on a Monday, and I started making them myself on Tuesday.  On Tuesday, approximately at 1200hrs, my syringe cap rebounded and poked me on my left thumb.  

In that split second, I was thrilled that I was not bleeding.  Few seconds later, I started bleeding.  I stopped everything I was doing, removed my gloves, and stepped away from the iodine room.  I was hot, literally. As I walk toward the sink while calling out to the RSO (radio-safety officer), "Collin! I poked myself with I-131."  I was calm but frantic inside.  Enough I-131 in your body can ablate or destroy your thyroid.  However, takes a good amount of I-131 activity to do that, but still!  Without going into too much detail, I was trying to squeeze all that blood out as if a poisonous snake just bit me to try to rid all the removable contamination.  

Think of radioactivity as dust particles that you may not be able see and any residue left behind unshielded is radioactive.  In this scenario, my thumb was unshielded and radioactive.  Some of the contamination is also absorbed by the surrounding skin while a little might have traveled into your bloodstream.  I know that there wasn't too much activity in my needle-stick because it was an extremely light stick just barely into the epidermis.   That day, I went home with a blue glove on my left hand.  I was so embarrassed that I kept my mitten on even after getting indoors when I went to Zenon Dance School.  The purpose of wearing the blue glove for the night is so one, I don't ingest any of the activity if there is any left over and secondly, I can continue to perspire out the remaining activity. 



It's been a few weeks since I have been compounding.  I shall say that I am super careful and focused in the Iodine room when I compound these capsules.  I never ever want to go through that experience again-- to have to leave work radioactive!  I continuously challenge myself to work through it efficiently, which means that I need to be fast, but also clean without contamination.  The last thing you want to do is to stay in the iodine room and take your sweet time making the capsules because every second you spend in the room, you are exposed to iodine radiation.

Below is an image of one of the procedures done with the compounded capsules.


To give you a brief overview of what it's like to be in the iodine room, I will show you through pictures:)  We all love visual references!  When it's time for me to compound these capsules, I always feel as if I got punished and have to go to my corner.  It's called the 'iodine room' because it's segregated and it's a small room where all you do is make iodine-131 capsules.


This syringe holds a maximum of 0.3mL.  It's also known as an insulin syringe. 

As you see, the insulin syringe is tiny compare to my hand!  Usual dose of iodine-131 capsule is anywhere from 0.005mL to 0.14mL.  0.005mL is not even a graduated line and 0.14 mL would be on the 14th graduated line.  Essentially, I have to draw the amount, which is in solution, in the syringe, and then inject the liquid into the capsule for ingestion.


This picture depicts how I usually compound capsules.  My arms are in a fume hood called the glove box, and it's a hood designated for compounding iodine 131 capsules.  Because I-131 is volatile, it has to be compounded in a negative pressure hood so the volatile isotope does not get into the air you breathe.  The air is also monitored on a regular basis.  It is very difficult to manipulate in the hood especially having to hold all the heavy, leaded shields.  However, with time, you eventually get used to it.  In my first week of compounding, I took a long time just to make ONE capsule.  Few weeks later, today, I can make one capsule within few minutes.  Unfortunately, on a bad day, it'll take longer than a few minutes to make one capsule because you just canot get the exact amount that you want.  0.01mL vs 0.02mL can be a huge difference in activity given that I'm working with a highly concentrated amount of activity.  If each vial only has 0.25mL, you can imagine the amount of liquid I am working with.

Glove Box- arm holes where to place your arm through then manipulate the compounding procedure

See the barrier between my body and the iodine-133 in the hood? Not the most comfortable position
Side view...If you can see the top of the vial, then you're being blasted with lots of radiation:D Try not to look!

It really only takes one I-131 needle-stick for you to challenge yourself to never get poked again:p  The day after the incident, I really, really did not want to go near the iodine room, not to mention make the capsules!  I was so frightened by the experience I wish I never had to make another capsule.  Although I learned the hard way by setting myself radioactive, I'm glad it happened in this case.  Now, I have better technique, and I am more confident when I'm in the iodine room compounding with I-131.
Look closely! Yes, it says 'piglet' :)

More association to the title of my blog:) I love my job. I get to milk the cows and clean the pigs at my pharm!  Hope you enjoyed my entry! Send me a message if you have any questions or concerns!