title: An anthropomorphic multimodality (CT/MRI) head phantom prototype for end-to-end tests in ion radiotherapy.
abstract: With the increasing complexity of external beam therapy "end-to-end" tests are intended to cover every step from therapy planning through to follow-up in order to fulfill the higher demands on quality assurance. As magnetic resonance imaging (MRI) has become an important part of the treatment process, established phantoms such as the Alderson head cannot fully be used for those tests and novel phantoms have to be developed. Here, we present a feasibility study of a customizable multimodality head phantom. It is initially intended for ion radiotherapy but may also be used in photon therapy. As basis for the anthropomorphic head shape we have used a set of patient computed tomography (CT) images. The phantom recipient consisting of epoxy resin was produced by using a 3D printer. It includes a nasal air cavity, a cranial bone surrogate (based on dipotassium phosphate), a brain surrogate (based on agarose gel), and a surrogate for cerebrospinal fluid (based on distilled water). Furthermore, a volume filled with normoxic dosimetric gel mimicked a tumor. The entire workflow of a proton therapy could be successfully applied to the phantom. CT measurements revealed CT numbers agreeing with reference values for all surrogates in the range from 2 HU to 978 HU (120 kV). MRI showed the desired contrasts between the different phantom materials especially in T2-weighted images (except for the bone surrogate). T2-weighted readout of the polymerization gel dosimeter allowed approximate range verification.
authors.affiliation: German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology, Heidelberg, Germany.
authors.forename: Raya R
authors.initials: RR
authors.lastname: Gallas
authors.affiliation: German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology, Heidelberg, Germany.
authors.forename: Nora
authors.initials: N
authors.lastname: Hünemohr
authors.affiliation: German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology, Heidelberg, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Runz
authors.affiliation: German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology, Heidelberg, Germany.
authors.forename: Nina I
authors.initials: NI
authors.lastname: Niebuhr
authors.affiliation: German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology, Heidelberg, Germany; Heidelberg University Hospital, Department of Radiation Oncology, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany; Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120 Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Jäkel
authors.affiliation: German Cancer Research Center (DKFZ), Division of Medical Physics in Radiation Oncology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology, Heidelberg, Germany. Electronic address: s.greilich@dkfz.de.
authors.forename: Steffen
authors.initials: S
authors.lastname: Greilich
mesh_terms: D000886:Anthropometry / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006257:Head / Q000528:radiation effects*; D063193:Heavy Ion Radiotherapy / Q000295:instrumentation / Q000379:methods; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D064847:Multimodal Imaging / Q000295:instrumentation; D019047:Phantoms, Imaging; D066330:Printing, Three-Dimensional; D061766:Proton Therapy / Q000295:instrumentation* / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D061089:Radiotherapy, Image-Guided / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
keywords: 3D dosimetry; 3D printing; 3D-Dosimetrie; 3D-Druck; Bestrahlungsplanung; Dosimetriegel; Ion radiotherapy; Ionenstrahl-Therapie; Partikeltherapie; Protonentherapie; Qualitätssicherung; ion beam therapy; polymerization gel dosimeter; proton therapy; quality assurance; rapid prototyping; treatment planning