The mask is locked down on the sides and top so he doesn't move. The small white squares are the guide marks so that his position was always precisely the same (the table he's on goes up and down to get him lined up with the laser dots coming from the walls--I swear, it was like being inside a sci-fi film). A wonderful tech named Debbie decorated the mask for him--we brought it home when he finished radiation and have it in his bedroom. He has a bite blocker in his mouth to keep his teeth and mouth still and in position. The table itself was narrow and hard and the room was always freezing--the techs got used to grabbing at least three heated blankets every time we came. Once everyone left the room and the 12-inch thick lead-lined door was closed, Jake got to lie there for 15-20 minutes while the machine moved around him and delivered its radiation at precise locations. The only real hardship Jake experienced during these sessions was the time Troy forgot to change the music and Jake had to listen to country.
Don't forget to read the next post down--I was busy updating today :)