Thesis defense of Claus Maximilian Bäcker

In-vivo monitoring of the delivered dose is desirable in radiation therapy. Radionuclides generated during the proton irradiation can be used for imaging with nuclear medicine methods after the treatment session. In order to improve these techniques, this work focuses on three different aspects of nuclear physics from basic nuclear physics measurements to a clinical validation. The most relevant nuclear interaction is the production of 11C from carbon as this nuclear interaction is used as a monitor react ion for the measurement of several other radionuclides. Furthermore, this is one of the relevant residuals produced from the tissue nuclei. As the data from the literature scatter by about 15 %, a new reference cross section value of (68 ± 3) mb at 97 MeV is determined from the cross sections measured in different settings. In a second part, the activation of iodine during proton irradiation is investigated. Several radionuclides are produced from iodine which decay by the emission of positrons and can potentially be used for PET imaging subsequent to the fractional treatment. In the last step, the activation of titanium implants is investigated. A benchmarking test including MC simulations is perform ed which study reveals the limited applicability of PET imaging with implants for field verification in proton therapy.

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