Some more about proton therapy

proton compensator and aperture

I finally got my hands on one of the brass apertures that was used for my proton radiation therapy.  It took a few months for the radioactivity to decay to safe levels, and my parents were finally in the area and picked it up for me.  That’s it on the right.  It governed the shape of the radiation beam that was fired at my chest/neck, and was milled to the exact shape needed to treat my tumor from a certain angle that minimized exposure to the healthy bits in my body.  This particular disk was just one of several used for the upper half of my treatment area.  My tumor was so big that they had separate disks that they swapped out to treat the lower half of my tumor.  The treatment area was double what the cutout in the brass disk is.  The baseball is just there to give a size reference.  When I told you I had a cancerous tumor the size of a softball in my chest, I was not exaggerating.

The blue plastic disk is the compensator, which I’ve mentioned before, which dictates how deep the radiation penetrated into my body.  Areas with less plastic absorbed less energy, allowing the radiation beam to penetrate deeper into my tissues.  Like the 6 brass apertures, there were corresponding plastic compensators to for each angle of treatment, and so while I don’t know that this particular pair were used together, it gives a better picture of how the technology works.  The brass aperture defined the area the protons were allowed to hit me, the plastic compensator defined how deep they went inside me.