The Munich Fission Neutron Therapy Facility MEDAPP at the research reactor FRM II

Strahlenther Onkol. 2008 Dec;184(12):643-6. doi: 10.1007/s00066-008-1878-3. Epub 2008 Dec 24.


Purpose: At the new research reactor FRM II of the Technical University of Munich (TUM), the facility for Medical Applications (MEDAPP) was installed where fast neutrons are available as a beam for medical use.

Material and methods: Thermal neutrons induce fission in a pair of uranium converter plates and generate fast neutrons which are guided to the patient by a beam tube. The maximum opening of the multi leaf collimator (MLC) is 30x20 cm2 WxH. The beam is characterized by neutron-photon mixed beam phantom dosimetry. Specific safety measures are outlined.

Results: The neutron and gamma dose rates are 0.52 Gy/min and 0.20 Gy/min, respectively, in 2 cm depth of a water phantom. The half maximum depth of the neutron dose rate in water is 5.4 cm (mean neutron energy 1.9+/-0.1 MeV). Conformity with the European Medical Devices Directive (MDD) 93/42/EEG, was proven so that MEDAPP has a CE mark and since February 2007 also the license for clinical operation.

Conclusion: The clinical neutron irradiations of malignant tumors, which were performed at the former research reactor FRM until 2000, can be continued at FRM II under improved conditions. First patients were irradiated in June 2007.

Publication types

  • Comparative Study

MeSH terms

  • Fast Neutrons / therapeutic use*
  • Germany
  • Humans
  • Neoplasms / radiotherapy*
  • Nuclear Fission*
  • Nuclear Reactors*
  • Particle Accelerators
  • Phantoms, Imaging
  • Radiometry / methods*
  • Radiotherapy Dosage
  • Research*
  • Safety
  • Time Factors
  • Uranium


  • Uranium