Radioisotopes are used often and for quite different purposes. At the FRM II, radioactive cobalt-60 is produced by neutron capture using the stable isotope cobalt-59. The irradiated Co discs or wires are used primarily for the production of preparations which are used in density or level measurements and for calibration, as well as for sterilization.
Radioisotopes have many advantages for diagnosis:
- They make fine structures visible,
- the organs concerned can be observed from the outside,
- and the method only requires a short time.
- The results of the study are normally available immediately and are less intrusive for the patient than the alternative, surgical diagnosis, would be.
Some radioisotopes are also used for cancer therapy and – bound to carrier materials or as an implant – placed directly into the tumour. There, they release their radiation and act only locally. An example is Lutetium (Lu-177), which is prepared at the FRM II using neutron radiation from Ytterbium (Yb-176) and used to treat so-called endocrine tumours (e.g. tumours in the stomach, intestines, pancreas, and lungs).
Other radioisotopes that are produced at the FRM II, are holmium-166 and terbium-161. They are mainly used for cancer therapy, sometimes for imaging.
The most important and most commonly used isotope in nuclear medicine is Technetium-99m. It has a very wide application range for diagnostic purposes and usually arises as a fission bi-product of the irradiation of uranium. Molybdenum-99 is to be produced in large quantities at the FRM II from 2018/2019 on (see Mo-99).
The following facilities are available for the production of radioisotopes at the FRM II: