66 Gray is far from moderate as a whole body dose. The 100% lethal onetime dose for gamma or beta rays (which you probably got one of) is around 10 Gray, LD50 i

66 Gray is far from moderate as a whole body dose. The 100% lethal onetime dose for gamma or beta rays (which you probably got one of) is around 10 Gray, LD50 is 3 Gray iirc. A wholebody dose of 2 Gray consequently would get you severe radiation sickness, depletion of white blood cells and possible secondary infections with some chance of death. Radiation therapy therefore needs to "aim" right, so as not to hit too much of the sensitive tissues like nerves, bone marrow, mucosa, etc. Edit: here is a chart for a comparison of typical doses: https://en.m.wikipedia.org/wiki/Sievert#/media/File%3A027_dose-ranges-sievert.jpg https://en.m.wikipedia.org/wiki/Sievert#/media/File%3A027_do... Hope you beat the cancer.