This report was prepared at the request of the International Atomic Energy Agency and presented at an Advisory Group Meeting on "Applications of Recent Radiobiological Research in Radiotherapy" held in Vienna, Austria, from 24-28 September 1979. Based on the recommendations of the Advisory Group, the I.A.E.A. has decided to initiate a coordinated international research programme entitled "Exploration of the Possibility of high LET RAdiation for Nonconventional Radiotherapy in Cancers". This programme will explore possible applications of corpuscular radiations (neutrons, protons, accelerated heavy ions, negative pi-mesons, thermal and epithermal neutrons) in cancer therapy. In addition, the programme will include research on in situ radiotherapy with unsealed radionuclides and thermal neutron capture. For further information on the programme, please contact Dr T. IWASAKI, Section of Radiation Biology, Division of Life Sciences, International Atomic Energy Agency, Wagramerstrasse 5, P. O. Box 100, A-1400 Vienna, Austria.