Emmylou, Are you going with him to his Dr. appts.? You really need to do that to get a clear understanding of what is going on. The mask is just that- made of a special fiber-fitted to his head, face and shoulders, the mask will bolt him down to the table when he receives rad. [it keeps him from moving and it allows the rad technicians to mark certain areas where they want to concentrate the radiation beam.] You can go with him to a rad tx. and see what he is experiencing. Our grandson went with us once and sat in the booth with the rad techs.Amy in the Ozarks