Author: Panse, R.E.
Paper Title Page
WEPME010 Patient-specific Intensity-modulation of a Slowly Extracted Beam at the HIT Synchrotron 2944
  • C. Schömers, E. Feldmeier, Th. Haberer, J. Naumann, R.E. Panse, A. Peters
    HIT, Heidelberg, Germany
  Since 2009 more than 1100 tumour patients have been treated at the Heidelberg Ion Therapy-Centre (HIT). The HIT synchrotron produces a library of energy, focus and intensity-variable pencil beams used to deliver dose distributions of utmost conformity to irregularly shaped target volumes. The required number of particles for each volume element of the tumour, which can vary by more than two magnitudes, is applied using the rasterscan technology. The irradiation-time and thus the patient throughput are highly sensitive to the achieved spill-structure driven by RF-Knockout extraction. Presently unfavourable fluctuations of the extracted intensity due to inhomogeneous phase space distribution of the beam are present. Recently a feedback-loop coupling the dose-defining ionisation chamber in front of the patient with the RF-Exciter was implemented allowing for the adaptation of the extracted intensity to the patient-specific treatment plan in real-time. The technical implementation and the impact on the clinical operation will be discussed.