Dr. A. Bel

Main activities
Research, Patient care, Teaching
Image guided adaptive radiotherapy, radiation treatment planning
Focus of research
  1. Research on image guided adaptive radiotherapy (IGART) is combined with advanced radiation treatment planning. Application of these new treatment techniques are focussing on mobile tumours (e.g. pancreas, oesophagus and bladder).
  2. Main research topics for brachytherapy include: objective criteria to judge the quality of a treatment plan and combination of dose delivered with external beam radiotherapy and brachytherapy with mathematical biological models. Such models enable a prediction of the efficacy of a specific treatment.
  3. Hyperthermia shows some exciting new developments: improved treatment planning and new techniques enabling treatment of new indications. Combined optimization of treatment planning of hyperthermia and radiotherapy is explored; this line includes both fundamental biological research and implementation of mathematical biological models in software.
  4. Our group participates in the Holland  proton therapy center. During the coming years we will design image guided proton irradiation techniques for mobile tumors, a presently unexlored area. The potential benefit of either proton or photon therapy will be explored by means of mathematical biological models, a new application for the models as being developed in our other research lines.
Key publications
  • van der Horst A , Wognum S, Dávila Fajardo R , de Jong R, van Hooft JE, Fockens P, van Tienhoven G, Bel A, Interfractional position variation of pancreatic tumors quantified using intratumoral fiducial markers and daily cone beam computed tomography. INT J RADIAT ONCOL 2013;87 (1):202-208 [PubMed]
  • Wognum S, Heethuis SE, Rosario T, Hoogeman MS, Bel A, Validation of deformable image registration algorithms on CT images of ex vivo porcine bladders with fiducial markers. MED PHYS 2014;41 (7):071916 [PubMed]
  • Lutkenhaus LJ , Visser J, de Jong R, Hulshof MCCM, Bel A, Evaluation of delivered dose for a clinical daily adaptive plan selection strategy for bladder cancer radiotherapy. RADIOTHER ONCOL 2015;116 (1):51-56 [PubMed]
  • Kok HP, Crezee J, Franken NAP, Stalpers LJA, Barendsen GW, Bel A, Quantifying the combined effect of radiation therapy and hyperthermia in terms of equivalent dose distributions. INT J RADIAT ONCOL 2014;88 (3):739-745 [PubMed]
  • Dinkla AM, van der Laarse R, Kaljouw E, Pieters BR, Koedooder K, van Wieringen N, Bel A, A comparison of inverse optimization algorithms for HDR/PDR prostate brachytherapy treatment planning. BRACHYTHERAPY 2015;14 (2):279-288 [PubMed]
All Publications
Curriculum Vitae

Personal details

Name: dr. Arjan (Adrianus) Bel
Gender: male
Date of birth: 23-1-1966
Place of birth: Leerdam, Netherlands
Nationality: Dutch


PHD degree
Institute: Antoni van Leeuwenhoek Huis
Date: 1991-1995
PhD degree: February 1996, (Vrije Universiteit, Amsterdam)
Daily supervisors: dr. J. Lebesque, dr. M. van Herk, promotor: prof. dr. H. Bartelink.
PhD thesis: “Conformal radiotherapy: hitting a moving target.” Study on image guided improvement of positional accuracy of patients during radiotherapy.

Master degree

University: Utrecht
Date: 1984-1990
Study: Physics, specialization: computational physics/medical image processing
Master thesis: “Detection of edges and corners.” Study on automatic recognition of structures in MRI and CT images.

Other education
Hospital physicist Belgium 2000 (until 2004).
Clinical physicist The Netherlands, 2006.
Various courses on management in health care (2005-2009).


Professional experience

Sept. 2004 – present: head radiotherapy physics, Academisch Medisch Centrum, Amsterdam.

  • General management of HR (~45 fte, including project workers).
  • Coordination and management of clinical physics tasks.
  • Involvement in financial management/investments at department level (annual budget ~17M).
  • Hands-on clinical work.


  • Started a research group from scratch.
  • Involvement in strategic coordination of department’s research direction.
  • Supervision of >30 BS/MS students.
  • Co-supervisor for 7 PhD students (finalized) + 10 PhD students (ongoing)

1999 – 2004: physicist/software engineer, Nucletron B.V., Veenendaal, Netherlands.

Development of treatment planning system for external beam radiotherapy; link between international customers/ users (Radiotherapy departments) and industrial R&D.

995-1999: Clinical physicist.

UZ Brussels, dept. of radiotherapy, Brussels, Belgium .
Physics support of the clinic, introduction of new developments for imaging and treatment planning for clinical use.

1991-1995: PhD student at NKI/AvL, Amsterdam.
See: Education.

1990-1991: Software engineer
Assignment on various software projects via employment agency.
research (2004-present)



  • European society for radiotherapy and oncology (ESTRO).
  • Paediatric Radiation Oncology Society (PROS).
  • Nederlands vereniging voor klinische fysica (NVKF).
  • Nederlandse vereniging voor radiotherapie en oncologie (NVRO).

Awards and prize-winning grants

Senior author of award winning studies:
1. ESTRO-Jack Fowler award Barcelona "On-line dose calculation on cone beam CT for lung tumors", DC van Rooijen, G. Stippel, N. van Wieringen, A. Bel, 2010
2. ESTRO best poster award Barcelona "Prostate PDR brachytherapy: is it necessary to use an adaptive approach?" A Dinkla, P. Meijnen, B.R. Pieters, C. Koedooder, N. van Wieringen, R. van der Laarse, J.N. van der Grient, A. Bel, 2012
3. ESTRO best poster award Geneva "Cardiac volume reduction during chemo-radiotherapy of esophageal cancer patients" M. Kamphuis, LJ. Lutkenhaus, N. van Wieringen, MCCM Hulshof, A. Bel, 2013
4. ESTRO-Accuray Award, Vienna “Considerable intra-breath-hold motion and inter-breath-hold position variation of pancreatic tumors.” E. Lens, A van der Horst, E Versteijne, G van Tienhoven, A. Bel 2015
5. Best session presentation, Amsterdam Children Symposium “Radiotherapy in children, is there a difference with adults?” S.C. Huijskens, I.W.E.M van Dijk, M.A.J. de Jong, J. Visser, R. Dávila Fajardo, C.R.N. Rasch, T. Alderliesten, A. Bel, 2016
6. Session winning Award Amsterdam Kindersymposium “Respiratory-induced diaphragm motion during radiotherapy” S.C. Huijskens, I.W.E.M van Dijk, M.A.J. de Jong, J. Visser, R. Dávila Fajardo, C.R.N. Rasch, T. Alderliesten, A. Bel, 2017
7. Best presentation Award, First Quantivision symposium, Amsterdam “Dose warping uncertainties for the cumulative rectal wall dose from brachytherapy in cervical cancer” L. van Heerden, N. van Wieringen‎, C. Koedooder‎, B.R. Pieters‎, C.R.N. Rasch‎, A. Bel , 2017
8. 2nd prize best poster Award, First Quantivision symposium, Amsterdam “Comparison of respiratory-induced motion during radiotherapy between children and adults” S.C. Huijskens, I.W.E.M van Dijk, J. Visser, C.R.N. Rasch, T. Alderliesten, A. Bel 2017
9. ESTRO Junior Brachytherapy Travel Grant Vienna “ Dose warping uncertainties for the cumulative rectal wall dose from brachytherapy in cervical cancer” L. van Heerden, N. van Wieringen‎, C. Koedooder‎, B.R. Pieters‎, C.R.N. Rasch‎, A. Bel , 2017


Various other activities

  • Reviewer for leading papers in the field: International Journal of Radiation Oncology, Biology, Physics; Medical Physics; Physics in Medicine and Biology; Radiation Oncology; Radiotherapy and Oncology; British Journal of Radiology, Physica Medica
  • Reviewer for funding organizations (Cancer UK, KWF).
  • Reviewer and chairman for a number of international conferences (i.e. annual ESTRO-meeting, ICCR).
  • Member of STW-user committee MRI-Linac project, collaboration between UMC Utrecht, Philips and Elekta (2008-2014).
  • Chairman of NVKF committee for educational activities (“Kring radiotherapie”) (2017 - ; 2013-2017: member). Meetings 4-6x/year.
  • Co-organizer lectures institute Quantivision (2016 - ).
  • Scientific committee user meetings Brachytherapy Nucletron/Elekta (2010-2014).
  • Scientific committee user meeting Treatment Planning External Beam Elekta (2014).
  • Consultant treatment planning system External beam irradiation (2004-2010), Nucletron B.V. Veenendaal, the Netherlands.
Research programmes

Innovative image guided radiotherapy

Image guidance is essential for high-precision dose delivery in radiotherapy. It comprises the pre-treatment localization of the target with CT and/or MRI as well as safeguarding patient positioning during treatment. Especially the introduction of the linac mounted Cone Beam CT has opened a new realm of possibilities to enhance treatment precision, including:

  • Localization of mobile tumors and organs-at-risk.
  • Improvement of visualization of the relevant anatomy by application of markers in or around the tumor.
  • Bio-mechanical modeling of the internal anatomy.  
  • Strategies for geometrical and dosimetric corrections of the treatment, including adaptive radiotherapy ( ART).

Focus is on mobile gastrointestinal/abdominal tumors (pancreatic, bladder and esophagus).
Moreover, external beam radiotherapy is combined with other techniques:

  • Brachytherapy: the tumor is irradiated locally with a radioactive source
  • Hyperthermia: the effect of irradiation is enhanced by heating.

Research includes modeling and quantification of the synergistic effect of these combinations.



Dr. A. Bel
Dr. T. Alderliesten PhD
Dr. P.A.N. Bosman PhD (Centrum Wiskunde en Informatica (CWI), Amsterdam)
Dr. J. Crezee PhD
Dr. I.W.E.M. van Dijk

Dr. A. van der Horst
Dr. P. Kok

PhD Students
Drs. L.E. van Heerden
M.A.J. de Jong
M.C. van der Meer MSc
Drs. E. Versteijne
Z. Wang

Dr. R. van der Laarse (Quality RT BV)

Prof. dr. C.R.N. Rasch (Image guided and physics application in the clinic)

Other research related activities
  • Membership of medical or scientific committee, NVKF, Member scientific committee ("Kring klinische fysica RT")
  • Membership of medical or scientific committee, NVRO, Paediatric oncology
  • Membership of medical or scientific committee, Paediatric Radiation Oncology Society, Peadiatric radiotherapy physics network
  • Consultant, Elekta A.B. Stockholm, Sweden
  • Consultant, Medlogix, Rome, Italy
Current research funding
  • KWF Kankerbestrijding
  • NWO
  • Stichting KIKA
  • Toegepaste en Technische Wetenschappen (TTW)
  • Universiteit Twente