title: Challenges of radiotherapy: report on the 4D treatment planning workshop 2013.
abstract: This report, compiled by experts on the treatment of mobile targets with advanced radiotherapy, summarizes the main conclusions and innovations achieved during the 4D treatment planning workshop 2013. This annual workshop focuses on research aiming to advance 4D radiotherapy treatments, including all critical aspects of time resolved delivery, such as in-room imaging, motion detection, motion managing, beam application, and quality assurance techniques. The report aims to revise achievements in the field and to discuss remaining challenges and potential solutions. As main achievements advances in the development of a standardized 4D phantom and in the area of 4D-treatment plan optimization were identified. Furthermore, it was noticed that MR imaging gains importance and high interest for sequential 4DCT/MR data sets was expressed, which represents a general trend of the field towards data covering a longer time period of motion. A new point of attention was work related to dose reconstructions, which may play a major role in verification of 4D treatment deliveries. The experimental validation of results achieved by 4D treatment planning and the systematic evaluation of different deformable image registration methods especially for inter-modality fusions were identified as major remaining challenges. A challenge that was also suggested as focus for future 4D workshops was the adaptation of image guidance approaches from conventional radiotherapy into particle therapy. Besides summarizing the last workshop, the authors also want to point out new evolving demands and give an outlook on the focus of the next workshop.
authors.affiliation: ICR, London, United Kingdom. Electronic address: antje.knopf@icr.ac.uk.
authors.forename: Antje
authors.initials: A
authors.lastname: Knopf
authors.affiliation: ICR, London, United Kingdom.
authors.forename: Simeon
authors.initials: S
authors.lastname: Nill
authors.affiliation: Universitätsklinikum Erlangen, Germany.
authors.forename: Indra
authors.initials: I
authors.lastname: Yohannes
authors.affiliation: GSI, Darmstadt, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Graeff
authors.affiliation: MGH, Boston, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Dowdell
authors.affiliation: Uni Heidelberg, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Kurz
authors.affiliation: NKI, Amsterdam, Netherlands.
authors.forename: Jan-Jakob
authors.initials: JJ
authors.lastname: Sonke
authors.affiliation: KVI-Center for Advanced Radiation Technology, University of Groningen, Netherlands.
authors.forename: Aleksandra K
authors.initials: AK
authors.lastname: Biegun
authors.affiliation: Unispital, Zurich, Switzerland.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lang
authors.affiliation: UCL, London, United Kingdom.
authors.forename: Jamie
authors.initials: J
authors.lastname: McClelland
authors.affiliation: UCL, London, United Kingdom.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Champion
authors.affiliation: ICR, London, United Kingdom.
authors.forename: Martin
authors.initials: M
authors.lastname: Fast
authors.affiliation: Universitätsklinikum Erlangen, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Wölfelschneider
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Italy; Department of Radiation Oncology, Heidelberg University Hospital, Germany.
authors.forename: Chiara
authors.initials: C
authors.lastname: Gianoli
authors.affiliation: Radiation Oncology Department, SLK-Klinik Heilbronn, Germany.
authors.forename: Antoni
authors.initials: A
authors.lastname: Rucinski
authors.affiliation: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano and Bioengineering Unit, CNAO Foundation, Pavia, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Baroni
authors.affiliation: Oncoray - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital C.G. Carus, TU Dresden, Helmholtz-Zentrum Dresden-Rossendorf, DKTK, Dresden, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Richter
authors.affiliation: Erasmus University Medical Center, Rotterdam, Netherlands.
authors.forename: Steven
authors.initials: S
authors.lastname: van de Water
authors.affiliation: MGH, Boston, USA.
authors.forename: Clemens
authors.initials: C
authors.lastname: Grassberger
authors.affiliation: PSI, Villigen, Switzerland.
authors.forename: Damien
authors.initials: D
authors.lastname: Weber
authors.affiliation: Aarhus University, Denmark.
authors.forename: Per
authors.initials: P
authors.lastname: Poulsen
authors.affiliation: Hokkaido University, Sapporo, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Universitätsklinikum Erlangen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bert
mesh_terms: D004493:Education; D056973:Four-Dimensional Computed Tomography; D008279:Magnetic Resonance Imaging; D009068:Movement; D011880:Radiotherapy Planning, Computer-Assisted; D061089:Radiotherapy, Image-Guided
keywords: 4D dosimetry; 4D optimization; Motion mitigation; Motion modeling; Motion monitoring; Moving targets