A few years back there was only about a dozen but looks like when I researched it just now there are now about 45 of these Proton Radiation machines see link: https://www.beckershospitalreview.com/oncology/45-cancer-centers-with-proton-therapy-in-the-us.html#:~:text=There%20are%20only%2045%20cancer,radiation%20directly%20to%20a%20tumor.

I live in Wisconsin, and we are just completing one at Froedtert & MCW Health and the UW-Carbone Cancer clinics. I am a patient at Froedtert and William Olsen is right they are massive. Matter of fact both of these clinics built them from the foundation for the new buildings where they will be housed. I wish I had one of these back in 2008 when I received my first head and neck cancer and had 35 rounds (70GY) of the Photon radiation, I would have avoided my second and third cancer which I unfortunately received in 2024. God Bless.