What are the Chemists called who are synthesizing radioactive isotopes for PET scans for Cancer Patients?

Radioactive isotopes are produced in cyclotrons, radioisotope generators or by Nuclear Bombardment. So they're most probably Nuclear physicists. Although therapeutic Radiopharmacists are also involved in the same medical field, But the supply for radioactive isotopes comes from nuclear reactors, and they're physicists who work on nuclear reactors.