Radiation - induced base damage – FPG - sensitive sites in plasmid DNA

Major progress of the Heidelberg ion beam cancer ther-apy centre took place in 2007. The first turn of the beamin the synchrotron was reached on February, 7th. Firstbeam in a treatment room was achieved on March, 20th.Until December, 16ththe beam performance in the firsttwo treatment rooms was pushed to the quality which isrequired for patient treatment. The LINAC was renderedto clinic for operation responsibility in June. The handingover of the accelerator parts up to three horizontal beamstations to the clinic is actually in preparation.In parallel to the beam commissioning work the world-wide first gantry for carbon beam was assembled duringthe year 2007. After finishing the extensive survey andalignment campaign for the gantry components the beamcommissioning started in January 2008. The first beam atthe isocenter of the gantry was measured on January, 4th.The main focus of the GSI work is now to finalise thebeam commissioning for the gantry. Beam commissioning of the Accelerator In January 2007 the Medium Energy Beam Transport line(MEBT), the synchrotron and the High Energy BeamTransport Line (HEBT) were connected to the LINAC.The beam commissioning started in February and alreadyon February, 7ththe first turn of the beam was reached inthe synchrotron.Rapidly beam could be captured and accelerated in thesynchrotron and the first beam extraction took place onMarch, 12th. Then the beam was transported further downthe HEBT and first beam in the isocenter of the horizontaltreatment room 2 could be measured on March, 20th. Itshould be notred, that the beam diagnostic componentsfor all the accelerator sections had been delivered by GSI.[1] Figure 1: First beam in horizontal place 2 measured withthe isocenter diagnosticAll the rest of the year the beam commissioning wasneeded to push the beam performance to the full require-ments needed for patient treatment. A full set of any com-bination of 255 energies, 10 different intensities and fourbeam sizes had to be tuned for both carbon and protonbeams and for each of the two horizontal treatmentrooms. This effort required a significant amount of auto-matic interpolation features of the accelerator control sys-tem. [2]. In addition new operation modes were estab-lished, like the spill-interupt process (see Fig. 2). Figure 2: extracted beam with spill-interrupt From March on the beam was also delivered to the treat-ment rooms for the commissioning with beam of thetreatment technique, which is delivered by the companySiemens Medical Solutions. The accelerator operation forthis task was performed by the HIT GmbH, the operatingcompany of the university hospital. Figure 3: Horizontal treatment place In June the beam performance tests, the documentationand the training of the operation staff had reached thepoint that the LINAC could be handed over to the HITEXTERNAL-HIT-01