Research interest
The analysis of dosimetric and geometric uncertainties in radiotherapy forms the main focal point of our research group. The development and implementation of electronic portal imaging to improve geometric accuracy is a long-lasting activity of the group. The Varian PortalVision device was originally developed in the NKI and also software for portal image analysis in 2D and 3D was developed and clinically implemented (with Harm Meertens and Kenneth Gilhuijs). In NKB projects, patient setup and treatment verification for conformal radiotherapy using dynamic beam intensity modulation is studied (with Kenneth Gilhuijs). Also dosimetric applications of EPIDs are under investigation (with Ben Mijnheer). A large number of our clinical protocols apply electronic portal imaging in combination with decision rules to minimize setup errors (with Joos Lebesque). These protocols have been in use for a number of years and have been applied for thousands of patients, eliminating all systematic setup errors above a pre-set threshold (e.g., 5 mm for prostate),
Many software tools have been developed in the EU project CONQUEST (with Harry Bartelink). These software tools include interfaces to a range of treatment planning systems and extensive tools for plan visualization and tumor delineation. This software is currently used to collect and analyze data in clinical trials. For connectivity, a DICOM server and client was developed (with Lambert Zijp). Extensive software for 3D image processing is available in the department. Methods have first been developed and validated to register CT and MRI of the head and the pelvis, CT and SPECT of the head, CT, SPECT and PET of the lungs (with Joos Lebesque and Saar Muller) and to measure organ motion. We have also implemented respiration correlated CT scanning and respiration gated PET scanning using in-house developed software (with Saar Muller and Christoph Schneider). The algorithms are currently in clinical use and are also applied in various other research projects to investigate uncertainties in radiotherapy and to derive rules for geometric margins (with Christoph Schneider and Joos Lebesque). A recent NKB project aims at measurement of delineation variability and improvement of delineation quality through multi-modality imaging (with Coen Rasch and Peter Nowak). Tools were developed to analyze delineation and shape differences in 3-D. Currently a large multi-center delineation study is being performed.
Within the framework of a project funded by the American NCI (with David Jaffray and Joos Lebesque) and in cooperation with an Elekta Consortium one of our linear accelerators has been equipped with a kilo-volt source and a flat-panel imaging device, enabling high quality cone-beam CT imaging on the treatment machine minutes prior to treatment. This technology is used to measure and correct organ motion of prostate, bladder (with Peter Remeijer), head and neck, and lung (with Eugene Damen and Katrien de Jaeger).
Key publications on PubMed
van Herk M, Meertens H. A matrix ionisation chamber imaging device for on-line patient setup verification during radiotherapy. Radiother Oncol 1988; 11: 369-378.)
van Herk M, Bruce A., Kroes APG, Shouman T, Touw A, Lebesque JV. Quantification of organ motion during conformal radiotherapy of the prostate by three-dimensional image registration. Int J Radiat Oncol Biol Phys 1995; 33: 1311-1320.)
Gilhuijs KGA, van de Ven PJH, van Herk M. Automatic three-dimensional inspection of patient setup in radiation therapy using portal images, simulator images, and computed tomography data. Med Phys 1996; 23: 389-399.)
Boellaard R, van Herk M, Mijnheer BJ. A convolution/superposition model to convert transmission dose images to exit dose distributions. Med Phys 1997; 24: 189-199.)
van Herk M, de Munck JC, Lebesque JV, Muller S, Rasch C, Touw A. Automatic registration of pelvic computed tomography data and magnetic resonance scans including a full circle method for quantitative accuracy evaluation. Med Phys 1998; 25: 2054-2067)
Rasch C, Barillot I, Remeijer P, Touw A, van Herk M, Lebesque JV, Definition of the prostate in CT and MRI: a multi-observer study. Int J Radiat Oncol Biol Phys 1999; 43: 57-66.)
van Herk M, Remeijer P, Rasch C, Lebesque JV, The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy. Int J Radiat Oncol Biol Phys 2000; 47: 1121-1135)
van Herk M, Remeijer P, Lebesque JV. Inclusion of geometric uncertainties in treatment plan evaluation. Int J Radiat Oncol Biol Phys. 52:1407-1422.
Dekker N, Ploeger LS, van Herk M. Evaluation of cost functions for gray value matching of two-dimensional images in radiotherapy. Med Phys. 2003 30: 778-784))
Ploeger LS, Betgen A, Gilhuijs KG, van Herk M. Feasibility of geometrical verification of patient set-up using body contours and computed tomography data. Radiother Oncol. 2003 66: 225-233)
More publications by Marcel van Herk on PubMed
List of relevant websites
ESTRO
Bibliographic sketch
1985 Master of Science (Cum laude) University of Amsterdam. Subject: the development of a liquid-filled electronic portal imaging device.
1985 Assigned on Dutch Cancer Foundation project NKI-8310, Subject: Accurate clinical dosimetry for the determination of tolerance dose. Project leaders: BJ Mijnheer and H Meertens.
1987 Assigned on Foundation of Technical Science project BGN66.0985. Subject: Development of a liquid ionizationdetector for megavoltage radiography. Project leader: H Meertens.
1988 Project leader of EU project A1024 QUIRT. Subject: QUality assurance and Imaging in Radiation Therapy.
1992 PhD. (Cum laude). Subject: An electronic portal imaging device; physics, development and application. Scientific committee: Prof. J Strackee, Prof. H Bartelink, BJ Mijnheer, PhD.
1992 Postdoctoral fellowship at Harvard Medical School. Subject: 3-D image registration for stereotactic radiotherapy. Supervisor: H Kooy, PhD.
1993 AvL fellowship. Subject: Imaging in radiation therapy.
1993-2001 Project leader of projects concerning: 3D image fusion (NKB94-777), electronic portal imaging (NKB98-1682), portal image dosimetry (STW BGN33.3240, NKB2000-2275), margins (NKB96-1308), data exchange for clinical trials (EC Conquest), and target volume delineation (NKB2000-2247).
1998 Staff member (full time research) of the Radiotherapy Cluster. Specialized in imaging and uncertainties in radiotherapy.
Awards
1988 ESTRO Varian clinical research award, "Clinical application of electronic portal imaging".
1989 Antoni van Leeuwenhoek Award.
Co-workers
Pos, Floris MD Academic staff
Steenbakkers, Roel MD Academic staff
Fitton, Isabelle PhD Postdoctoral fellow
Lotz, Heidi PhD Postdoctoral fellow
Sonke, Jan-Jakob PhD Postdoctoral fellow
Wendling, Markus PhD Postdoctoral fellow
Witte, Marnix PhD Postdoctoral fellow
McDermott, Leah Ba/Bs Graduate student
Smitsmans, Monique MSc Graduate student
Betgen, Anja RTT Radiographer
De Bois, Josien RTT Radiographer
Tielenburg, Rene RTT Radiographer
Brand, Bob MSc Software developer
Dijkstra, Jurjen Ing Software developer
Duppen, Joop Ing Software developer
Frenay, Michel MSc Software developer
Van der Geer, Joris MSc Software developer
Lambert Zijp Software developer