title: Evaluation of inter- and intrafractional motion of liver tumors using interstitial markers and implantable electromagnetic radiotransmitters in the context of image-guided radiotherapy (IGRT) - the ESMERALDA trial.
abstract: BACKGROUND
  With the development of more conformal and precise radiation techniques such as Intensity-Modulated Radiotherapy (IMRT), Stereotactic Body Radiotherapy (SBRT) and Image-Guided Radiotherapy (IGRT), patients with hepatic tumors could be treated with high local doses by sparing normal liver tissue. However, frequently occurring large HCC tumors are still a dosimetric challenge in spite of modern high sophisticated RT modalities. This interventional clinical study has been set up to evaluate the value of different fiducial markers, and to use the modern imaging methods for further treatment optimization using physical and informatics approaches.
  
  
  METHODS
  Surgically implanted radioopaque or electromagnetic markers are used to detect tumor local-ization during radiotherapy. The required markers for targeting and observation during RT can be implanted in a previously defined optimal position during the oncologically indicated operation. If there is no indication for a surgical resection or open biopsy, markers may be inserted into the liver or tumor tissue by using ultrasound-guidance. Primary study aim is the detection of the patients' anatomy at the time of RT by observation of the marker position during the indicated irradiation (IGRT). Secondary study aims comprise detection and recording of 3D liver and tumor motion during RT. Furthermore, the study will help to develop technical strategies and mechanisms based on the recorded information on organ motion to avoid inaccurate dose application resulting from fast organ motion and deformation.
  
  
  CONCLUSIONS
  This is an open monocentric non-randomized, prospective study for the evaluation of organ motion using interstitial markers or implantable radiotransmitter. The trial will evaluate the full potential of different fiducial markers to further optimize treatment of moving targets, with a special focus on liver lesions.
authors.affiliation: Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany. daniel.habermehl@tum.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Habermehl
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. patrick.naumann@med.uni-heidelberg.de.
authors.forename: Patrick
authors.initials: P
authors.lastname: Naumann
authors.affiliation: Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany. r.bendl@dkfz-heidelberg.de.|Medical Informatics, Heilbronn University, Heilbronn, Germany. r.bendl@dkfz-heidelberg.de.
authors.forename: Rolf
authors.initials: R
authors.lastname: Bendl
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK. uwe.oelfke@icr.ac.uk.
authors.forename: Uwe
authors.initials: U
authors.lastname: Oelfke
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK. Simeon.Nill@icr.ac.uk.
authors.forename: Simeon
authors.initials: S
authors.lastname: Nill
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. juergen.debus@med.uni-heidelberg.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.affiliation: Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany. stephanie.combs@tum.de.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
mesh_terms: D054893:Cone-Beam Computed Tomography; D057918:Fiducial Markers; D006801:Humans; D021621:Imaging, Three-Dimensional; D007103:Immobilization; D008099:Liver / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary; D009038:Motion; D056888:Patient Positioning; D011446:Prospective Studies; D019736:Prostheses and Implants; D011846:Radio Waves; D011880:Radiotherapy Planning, Computer-Assisted; D061089:Radiotherapy, Image-Guided / Q000295:instrumentation* / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D013686:Telemetry