In situ and in vivo treatment plan verification and beam monitoring as well as dose control during heavy-ion tumour therapy can be performed in principle by measurements of range distributions of beta(+)-emitting nuclei by means of PET techniques. For this purpose the performance of different types of positron camera as well as the results of in-beam PET experiments using beams of beta(+)-active heavy ions (15O, 17F and 19Ne with energies of 300-500 A MeV) are presented. Following the deduced performance requirements a PET scanner that is designed for clinical use in experimental heavy-ion therapy at GSI Darmstadt has been built. This limited angle tomograph consists of two large-area detector heads based on position sensitive BGO detectors and is predicted to perform the measurement of the end point of a beta(+)-emitting ion beam for the verification of a treatment plan with a precision better than 1 mm. The maximum dose applied in the patient thereby is of the magnitude of 10 mGy.

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Two distinct X-ray continuaC1 and C2 above the characteristic lines are observed in high-energy collisions between atoms with atomic numbers of 28 to 57. This structure is explained by a superposition of K molecular-orbital (KMO) radiation and of an intermediate L-K molecular-orbital (ILKMO) radiation of high intensity which is due to 2p sigma vacancies. In the framework of the dynamical theory of intermediate molecular phenomena and using a scaling of the H2 + correlation diagram with screened state-dependent charges good agreement between the shapes of the measured and calculated spectra is obtained.

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In vivo dose localization in light ion tumour therapy can be performed by measuring the range distributions of beta+ active ions in tissue employing positron emission tomographic techniques. For this purpose a multiplicative iteration scheme for reconstructing three-dimensional images from shift-variant, limited-angle data is presented. In the iterative correction steps the algorithm uses the geometric means of quotients calculated from the three-dimensional Radon transforms of the backprojected measured and approximated source distributions. When sources measured with poor statistics are reconstructed, an effective noise suppression is achieved.