Also how does radiation attack cancer cells more than normal cells?

doesnt really "attack" them more. my understanding (i might be wrong dont know a lot about radiation therapy) is that it damages DNA which messes up replication. cancer cells replicate much faster than normal cells and since their DNA gets messed up they die. the idea is to kill fast growing cells, and just keep hitting it hoping to kill off the cancer before the treatment or cancer kills the patient.

thats basically how both chemo drugs work too such as mercaptopurine and a lot of others; the drugs are assembled into the DNA as a "false" purine which makes the chains unstable and kills off fast growing cells. that’s why chemo patients lose their hair (follicles have a high turnover rate), have a lot of nausea (epithelial cells of the digestive tract are constantly reproducing), and other symptoms related to the death of normal cells that have a high turnover rate because the treatment cant discriminate between good cells and bad cells. its like dropping a bomb.

They do attack normal cells surrounding the cancer cells but the radiation is directed to a bulk of the cancer cells, radiation can not be used in single cells moving around. this is how the radiation therapy works.