|The candy-colored lines on the|
mask mark the outline of the nine
radiation angles used during
a 20-minute session. By the way,
that's my head inside the mask.
While I sincerely wish it wasn’t necessary, being treated with radiation is nonetheless full of wonder. This application of high-energy physics to clinical care makes an MRI scanner look like child’s play by comparison. There is absolutely no sensation to having my gray matter bombarded by x-rays. The only uncomfortable part of the procedure is the thermoplastic mask used to immobilize my head, which goes beyond anything Hannibal Lecter had to wear in “Silence of the Lambs.”
|The radiation beam comes out of the gantry|
above my head and can be rotated around me.
The linear accelerator that generates the x-ray beam is an impressive apparatus. It uses microwave technology to accelerate electrons through what’s called a “wave guide,” then allows these electrons to collide with a tungsten target. As a result of these collisions, high-energy x-rays are produced. These x-rays are shaped by a collimator as they exit the machine to create the customized beams referred to above. If this explanation whets your appetite, here’s a good YouTube video about IMRT.There’s something surreal about having accelerated atomic particles slamming silently into a heavy-metal target a few feet above your head, generating invisible rays that are bent by powerful magnets into beams that pass invisibly through the skull into your brain, and which then damage the DNA of cancer cells so they die and are eliminated from the body. I consciously experience none of this activity while immobilized in my Hannibal mask. Like so many things in life, I take as an act of faith that this marvel of technology will ultimately do me good.