Please explain if it is true that radiation can give you a tumor?

Yes. Radiation can have a deleterious effect on tissue, but the younger the patient the more susceptible to cancer. If the thyroid is radiated in young people it can cause cancer but not so in older people. If breast radiation from mammo is given yearly starting in the 20 year old, the breast can develop cancer. In older patients not so. Airline stewardesses who fly have higher incidence of CA.