11/16/08 - MU - Radiation Simulation

Radiation "Simulation" is an appointment to basically prepare and plan for radiation treatments. I didn't get all of the photos I wanted (the radiation techs/nurses were spared), but I will share some important ones.

The first part of the simulation is to make a custom-molded "mask." It is made from a type of plastic that becomes moldable when heated up. For that reason, the radiation technicians have me lay on a flat surface (the CT table - more on it later), soak the new, flat mask in some [very] warm water and then quickly put it down over my face. The briefly malleable plastic conforms to my features. I say features because the mask actually comes down to my upper chest. A tech pulled on the mask's nose, so I could breathe easier. It is shown below.


My radiation mask
The mask helps to accurately position me. It has 9 clips which lock to the table I am placed on (for the simulation, a CT (cat scan) table; for radiation treatments, the radiation table). Once clamped, it is very tight. The rest of my lower body has to be in an upright laying position on whatever table the mask is attached to.

Laser beams also help to position me. During the simulation, my body was aligned and pen marks (cross hairs) were drawn where the criss-crossed lasers intersected my body, as shown by the blue "+" signs in the photograph below. At the center of the plus signs located in the middle of my chest and stomach, I was also tattooed. This was done for when the pen marks washed away, a small "dot" tattoo was placed at the middle of those two plus signs. That way, in combination with the secured mask, the rest of my body could also be positioned by lining the tattoos back up with the laser beams.


Laser "targets"
Also visible in the image above is my "traditional" chemotherapy port. It is the small bump on the upper area of my right chest. It is basically a needle receptacle (rubberized dome) with a catheter (tube) that runs into my subclavicle vein. It is used to deliver chemo drugs or transfusions into my blood stream. It was surgically implanted after my brain tumor was removed and will stay in indefinitely unless there is a problem with it.

The cat scan was then used to image my entire spinal cord. If you aren't familiar with a cat scan, just imagine a popsicle stick be inserted into a doughnut hole. The popsicle stick is the table where I lay, and the doughtnut is the portion of the machine that surrounds me and takes "pictures." The table can move in and out of the hole. See the photo below. This scan relates the position of the mask and the laser beams to my spinal cord. The initial plan was to radiate my entire spinal cord, with a possible "boost" to the tumor area. After the initial simulation, my doctors decided to concentrate the radiation on the tumor, which is in my neck area. The tattoos weren't used to position my body, as the mask was enough to position me.


CT Scan machine
My next post will be about an actual radiation treatment, which includes more details and a movie of one...