Particle Therapy Immobilisation and Verification
J. Thiele1, D. Haak1, T. Hölscher1, C. Valentini1, E. G. C. Troost1-5, C. Richter1-4
1 Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
2 OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
3 Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology – OncoRay, Dresden, Germany
4 German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
5 National Center for Tumor Diseases (NCT), Partner Site Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, and; Helmholtz Association / Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden, Germany
This presentation will deal with the specific requirements for positioning and its verification in proton therapy patients, which differ from those in conventional photon therapy.
Stable reproducible positioning and immobilisation is very important, since the treatment times and thus duration of positioning in treatment position is somewhat longer. Efficient workflows with set verification schemes, e.g., for cranio-spinal irradiation (CSI), reduce the treatment time of the patients. Imaging is performed before each fraction and positioning is based exclusively on bony anatomy in the irradiation area. Fiducials as well as prescribed drinking or dietary protocols are used to support daily positioning and verification in the case of moving organs, such as oesophageal, pancreatic or prostate cancer.
During the course of proton beam therapy, anatomical changes, such as weight gain or loss and tumour shrinkage, may strongly influence the dose distribution. Therefore, regular weight checks and control CT scans are also performed for patients with head and neck tumours or non-small cell lung cancer.
The concept applied at the University Hospital Dresden will be presented using three examples: irradiation of head and neck tumours, prostate cancer and CSI.