title: Optimization of carbon ion and proton treatment plans using the raster-scanning technique for patients with unresectable pancreatic cancer.
abstract: BACKGROUND
  The aim of the thesis is to improve radiation plans of patients with locally advanced, unresectable pancreatic cancer by using carbon ion and proton beams.
  
  
  METHODS
  Using the treatment planning system Syngo RT Planning (Siemens, Erlangen, Germany) a total of 50 treatment plans have been created for five patients with the dose schedule 15 × 3 Gy(RBE). With reference to the anatomy, five field configurations were considered to be relevant. The plans were analyzed with respect to dose distribution and individual anatomy, and compared using a customized index.
  
  
  RESULTS
  Within the index the three-field configurations yielded the best results, though with a high variety of score points (field setup 5, carbon ion: median 74 (range 48-101)). The maximum dose in the myelon is low (e.g. case 3, carbon ion: 21.5 Gy(RBE)). A single posterior field generally spares the organs at risk, but the maximum dose in the myelon is high (e.g. case 3, carbon ion: 32.9 Gy(RBE)). Two oblique posterior fields resulted in acceptable maximum doses in the myelon (e.g. case 3, carbon ion: 26.9 Gy(RBE)). The single-field configuration and the two oblique posterior fields had a small score dispersion (carbon ion: median 66 and 58 (range 62-72 and 40-69)). In cases with topographic proximity of the organs at risk to the target volume, the single-field configuration scored as well as the three-field configurations.
  
  
  CONCLUSIONS
  In summary, the three-field configurations showed the best dose distributions. A single posterior field seems to be robust and beneficial in case of difficult topographical conditions and topographical proximity of organs at risk to the target volume. A setup with two oblique posterior fields is a reasonable compromise between three-field and single-field configurations.
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, INF 400, 69120, Heidelberg, Germany. Constantin.Dreher@stud.uni-heidelberg.de.
authors.forename: Constantin
authors.initials: C
authors.lastname: Dreher
authors.affiliation: Department of Radiooncology, Klinikum rechts der Isar, Ismaninger Str. 22, 81675, Munich, Germany. daniel.habermehl@tum.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Habermehl
authors.affiliation: Heidelberg Ion Beam Therapy Center (HIT), INF 450, 69120, Heidelberg, Germany. Swantje.Ecker@med.uni-heidelberg.de.
authors.forename: Swantje
authors.initials: S
authors.lastname: Ecker
authors.affiliation: Heidelberg Ion Beam Therapy Center (HIT), INF 450, 69120, Heidelberg, Germany. stephan.brons@med.uni-heidelberg.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Brons
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, INF 400, 69120, Heidelberg, Germany. rami.elshafie@med.uni-heidelberg.de.
authors.forename: Rami
authors.initials: R
authors.lastname: El-Shafie
authors.affiliation: Heidelberg Ion Beam Therapy Center (HIT), INF 450, 69120, Heidelberg, Germany. o.jaekel@dkfz-heidelberg.de.|Department of Medical Physics in Radiation Oncology, German Cancer Research Center, INF 280, 69120, Heidelberg, Germany. o.jaekel@dkfz-heidelberg.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Jäkel
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, INF 400, 69120, Heidelberg, Germany. Juergen.Debus@med.uni-heidelberg.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.affiliation: Department of Radiooncology, Klinikum rechts der Isar, Ismaninger Str. 22, 81675, Munich, Germany. stephanie.combs@tum.de.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
mesh_terms: D000368:Aged; D005260:Female; D063193:Heavy Ion Radiotherapy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000532:radiotherapy*; D061766:Proton Therapy / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*