Dosimetrists carefully calculate the dose of radiation to make sure the tumor gets enough radiation. Using computers, they develop a number of treatment plans that can best destroy the tumor while sparing normal tissue. Since treatment plans are often very complex, dosimetrists work with the radiation oncologist and the medical physicist to choose the treatment plan that is right for you.

Many dosimetrists start as radiation therapists and then, with very intensive training, become dosimetrists. Others are graduates of one- to two-year dosimetry programs. They are certified by the Medical Dosimetrist Certification Board.