  The radiotherapy of malignant diseases has reached much progress during the
past decade. Thus, intensity modulated radiation therapy (IMRT) and VMAT
(Rapidarc) now belong to the standard modalities of tumor treatment with high
energy radiation in clinical practice. In recent time, the particle therapy
(protons and partially with heavy carbon ions) has reached an important
completion of these modalities with regard to some suitable applications. In
spite of this enrichment essential features need further research activities
and publications in this field: Nuclear reactions and the role of the released
neutrons, electron capture of positively charged nuclei at lower projectile
energies (e.g. in the environment of the Bragg peak and at the distal end of
the particle track), correct dose delivery in scanning methods by accounting
for the influence of the lateral scatter of beam-lets. Deconvolution methods
can help to overcome these problems, which already occur in radiotherapy of
very small photon beams [1 - 8].
