Treating breast cancer usually involves radiation. “Radiation therapy works by damaging the genetic material within cancer cells and limiting their ability to successfully reproduce. When these damaged cancer cells die, the body naturally eliminates them. Normal cells are also affected by radiation, but they are able to repair themselves in a way that cancer cells cannot.” (This quote is taken from an unremembered website.)
I will be given partial breast 3DCRT radiation. (Translation, 3 dimension conformal radiation therapy.) It will be delivered using a linear accelerator. There will be a total of 10 treatments, 2 a day, 6 hours apart.
Here’s my understanding of how a Cliniac Linear Accelerator works:
A cathode emitter, a piece of metal that is heated, allows electrons to be “liberated.” These electrons are then directed toward an anode target, made of tungsten, and photons are released. These photons then go through a linear accelerator. Here, the photons are sped up at a uniform rate so that a beam can be formed. That beam then makes a 90 degree bend (using a bending magnet) in order to reach the treatment head (pictured above.) The area of my breast to be treated is oval in shape, and includes both where the tumor was removed and enough surrounding tissue to hopefully destroy any stray cancer cells that may still be lurking nearby. Once in the treatment head, the photon beam is modified using multileaf collimation (MLC). You can see the “leaves” in the picture – the ones in the center are retracted to construct the oval shape. I will be lying on a table, as still as possible, and the treatment head will rotate around me.
For those who wonder why physics is important, here is a prime example. The beam must be targeted in such a way that it doesn’t damage either my ribs or my right lung. (Because the cancer was in my right breast, we don’t have to worry about photons hitting my heart.)
This will happen next week at the Department of Radiation Oncology at KUMed. While I’m not really looking forward to being irradiated all alone in a concrete and lead walled room, I don’t think this part of the treatment will be too bad.