In physics, the proton (Greek πρῶτον / proton “first”) is a subatomic particle with an electric charge of one positive fundamental unit (1.60217653(14)×10−19 C), a diameter of about 1.65×10−15 m[1], and a mass of 938.272309(28) MeV/c2 (1.007276466(13) u, 1.6726×10−27 kg), or about 1836 times the mass of an electron. (full Wikipedia Entry)
What I know about proton physics would ‘fit on the head of a pin’ (to quote an olde English expression) but the definition above leads me to surmise that many billion protons would fit there.
I began my Proton Therapy treatments last Thursday at the Francis H. Burr Proton Therapy Center at Mass General Hospital. After entering the building at ground level I took the elevator down to treatment level. ( I hear that most if not all proton treatment facilities are ‘buried’ partly to shield radiation and partly because of the tremendous weight of the equipment.) A short wait ended in an invitation to visit the changing room, remove clothing below the waist and put on a hospital gown. I was then guided through a secure door and into what at first appeared to be a labyrinth of corridors with thick, shielding walls. After several turns I entered the treatment room and was greeted by a very relaxed and friendly group of technicians. The treatment room reminded me of a cluttered version of the sick bay on StarTrek’s (The Next Generation) Enterprise. Sci Fi had become reality. Lying down on the narrow treatment ‘table’ I was assisted to the correct position by the technicians who used lasers and the small tatoos on my sides and lower belly to line me up correctly. An X-ray and UltraSound were used to confirm my position. The technicians then took shelter in a shielded control room.
I kept very still, listened to various buzzes and whirrs from the gantry, and tried to sense whether I could feel a stream of particles (about 1836 times the mass of an electron) bombarding my prostate. In spite of the fact that I credit myself with being a relatively sensitive guy I could feel nothing!
After about two minutes the friendly technicians returned, helped me off the table and wished me “have a nice day”. Quite surreal! I returned to the changing room, got dressed and left the building.
Since then I have had two more treatments – all mirroring the first except that the proton beam is directed from alternating sides of my torso. So far I have experienced no worrying side effects.
