If radiation causes cancer why than doctors use radiation chemotherapy against cancer?

Because radiation therapy can kill cancer as well as cause it. If you don’t have cancer, you can reasonably avoid radiation. But if you already have it, it is more important to kill the cancer than to worry about the minor risk of causing more.

this way is curing bad with worse . this mean chemotrapy has many side effcets but u know that canser often lead to death . and chemotrapy or radiography make this happen latter . but most of the tims its lead to death sooner or latter .