• 

  Harald Paganetti

  • Title
    Professor & Director
  • Affiliation
    Department of Radiation Oncology at Massachusetts General Hospital & Harvard Medical School, Boston, USA.
  • Phone
    617-726-5847
  • Email
    hpaganetti@partners.org
  • Website
    http://gray.mgh.harvard.edu/

  • Reasearch Keywords
  • Biography
  • Research Program
  • Publications

  Radiation Physics; Monte Carlo Simulations in Proton Therapy

  Dr. Harald Paganetti is the Director of Physics Research at the Department of Radiation Oncology at Massachusetts General Hospital and a Professor of Radiation Oncology at Harvard Medical School, Boston, USA. He received his PhD in experimental nuclear physics in 1992 from the RheinischeGFriedrichGWilhelms University in Bonn, Germany, and has been working in radiation therapy research on experimental as well as theoretical projects since 1994. He has authored and coGauthored more than 120 peerGreviewed publications and is renowned particularly for his work on proton therapy. In 2012 he edited a book on “Proton Therapy Physics”. Dr. Paganetti has been awarded numerous research grants from the National Cancer Institute in the United States. He is a member of taskGgroups and committees for various associations such as the American Association of Physicists in Medicine (AAPM), the American Society for Therapeutic Radiology and Oncology (ASTRO), and the National Institutes of Health / National Cancer Institute. Further, he is an elected member of the National Council on Radiation Protection and Measurements (NCRP) and an Associate Senior Editor of the International Journal of Radiation Oncology, Biology, Physics. In 2013 he received the A. Clifford Barger Excellence in Mentoring Award from Harvard Medical School.

  The mission of physics research as given on our website (http://gray.mgh.harvard.edu/) is to improve outcome through physics innovation. Improving treatment outcome is the centerpiece of any research mission in radiation oncology. Specifically, physics traditionally has dealt with increasing the precision of treatment delivery, the accuracy of treatment dose prescription, and the quest for treatment plan optimization. The majority of topics in physics research is not considered basic research but is truly translational. Thus, physics research in radiation oncology is typically not aiming at long term goals where research results only find their way into the clinic via translation by vendors, but is aiming at developments together with the clinical staff that changes treatment delivery and planning for our patients in the short term, sometimes even while the patient is undergoing treatment. At the same time we also strive to create visions for longGterm improvements and even paradigm shifts in radiation oncology.
  Our physics division has traditionally focused on five main areas:

  • Physical dose conformation: We explore and develop radiation treatment techniques for optimum physical dose conformation to the tumor target volume. Our efforts are focused on proton radiotherapy and advanced photon treatments, as well as on their comparison
  • Intensity modulated treatments using photons and protons: Intensity modulation is crucial both in photon radiotherapy (IMXT) and in proton radiotherapy (IMPT). In particular, we develop robust optimization methods for handling uncertainty in IMPT, direct aperture optimization algorithms, VMAT plan optimization, and multiGcriteria planning methods.
  • Biological modeling: As a basis for treatment optimization we work on a variety of modeling projects including relative biological effectiveness in proton therapy, outcome models for the relationship between the dose distribution and clinical outcome, and spatial modeling of microscopic disease.
  • Motion in radiation therapy: We develop concepts and methods to consider the time component in the whole radiotherapy chain, from imaging over planning and optimization to treatment delivery. Special emphasize is on using proton scanned beam technology for treating lung cancers.

  Recent publications:

  1. Hünemohr N, Paganetti H, Greilich S, Jäkel O, Seco J.: Tissue decomposition from dual energy CT data for MC based dose calculation in particle therapy. Med Phys. 2014 Jun;41(6):061714. doi: 10.1118/1.4875976.
  2. Moteabbed M, Yock TI, Paganetti H.: The risk of radiation-induced second cancers in the high to medium dose region: a comparison between passive and scanned proton therapy, IMRT and VMAT for pediatric patients with brain tumors. Phys Med Biol. 2014 Jun 21;59(12):2883-99.
  3. Grassberger C, Daartz J, Dowdell S, Ruggieri T, Sharp G, Paganetti H.: Quantification of proton dose calculation accuracy in the lung. Int J Radiat Oncol Biol Phys. 2014 Jun 1; 89(2):424-30.
  4. Gerweck LE, Huang P, Lu HM, Paganetti H, Zhou Y.: Lifetime increased cancer risk in mice following exposure to clinical proton beam-generated neutrons. Int J Radiat Oncol Biol Phys. 2014 May 1;89(1):161-6.
  5. Sethi RV, Giantsoudi D, Raiford M, Malhi I, Niemierko A, Rapalino O, Caruso P, Yock TI, Tarbell NJ, Paganetti H, MacDonald SM.: Patterns of failure after proton therapy in medulloblastoma; linear energy transfer distributions and relative biological effectiveness associations for relapses. Int J Radiat Oncol Biol Phys. 2014 Mar 1;88(3):655-63.
  6. Dowdell S, Grassberger C, Paganetti H.: Four-dimensional Monte Carlo simulations demonstrating how the extent of intensity-modulation impacts motion effects in proton therapy lung treatments. Med Phys. 2013 Dec;40(12):121713. doi: 10.1118/1.4829500.
  7. Paganetti H.: Advancing (proton) radiation therapy. Int J Radiat Oncol Biol Phys. 2013 Dec 1;87(5):871-3.
  8. Grosse N, Fontana AO, Hug EB, Lomax A, Coray A, Augsburger M, Paganetti H, Sartori AA, Pruschy M.: Deficiency in homologous recombination renders Mammalian cells more sensitive to proton versus photon irradiation. Int J Radiat Oncol Biol Phys. 2014 Jan 1;88(1):175-81.
  9. Testa M, Verburg JM, Rose M, Min CH, Tang S, Bentefour el H, Paganetti H, Lu HM.: Proton radiography and proton computed tomography based on time-resolved dose measurements. Phys Med Biol. 2013 Nov 21;58(22):8215-33.
  10. Paganetti H and van Luijk P: Biological considerations when comparing proton therapy with photon therapy. Seminars in Radiation Oncology 2013 23: 77-87; Top 5 most downloaded papers in Seminars in Radiation Oncology in the first half of 2013
  11. Carabe A; España A; Grassberger C and Paganeti H: Clinical consequences of Relative Biological Effectiveness variations in proton radiotherapy of the prostate, brain and liver. Physics in Medicine and Biology 2013 58: 2103-2117
  12. Ramos-Mendez JA; Perl J; Faddegon B; Schuemann J and Paganeti H: Geometrical splitting technique to improve the computational efficiency in Monte Carlo calculations for proton therapy. Medical Physics 2013 40: 041718
  13. Zeng C; Giantsoudi D; Grassberger C; Goldberg S; Niemierko A; Paganetti H; Efstathiou JA and Trofimov A: Maximizing the biological effect of proton dose delivered with scanned beams. Medical Physics 2013 40: 051708
  14. Cho J; Ibbott G; Gillin M; Gonzalez-Lepera C; Min CH, Paganetti H, Zhu X; El Fakhri G and 17Mawlawi O: Elemental tissue composition in proton treatment patients determined using positron emission tomography. Physics in Medicine and Biology 2013 58: 3815-3835
  15. Dowdell S; Grassberger C; Sharp GC and Paganetti H: Interplay effects in proton scanning for lung: A 4D Monte Carlo study assessing the impact of tumor and beam delivery parameters. Physics in Medicine and Biology 2013 58: 4137-4156.
• 

  Jan Seuntjens

  • Title
    Professor & Director
  • Affiliation
    McGill University, Medical Physics Unit
  • Phone
    514-934-1934 x44124
  • Email
    jan.seuntjens@mcgill.ca
  • Website
    http://www.mcgill.ca/medphys/

  • Reasearch Keywords
  • Biography
  • Research Program
  • Publications

  Radiation Physics and Dosimetry; Monte Carlo Calculations; Calorimetry; Detectors; Small Fields

  Seuntjens is Professor and Director of Medical Physics at the Medical Physics Unit, McGill University. His research topics revolve around the applications of advanced dosimetry techniques in clinical radiation therapy. This includes development of new detectors in small field dosimetry, radiation standards, as well as the application of Monte Carlo techniques for radiation transport calculations at the macro and microscopic level. Dr. Seuntjens is also investigating the application and clinical translation of modulated electron radiation therapy as well as other clinically-inspired research topics in a collaborative context with other PIs. Dr. Seuntjens’ research

  Research topics revolve around the applications of advanced dosimetry techniques in clinical radiation therapy. This includes development of new detectors in small field dosimetry, radiation standards, as well as the application of Monte Carlo techniques for radiation transport calculations at the macro and microscopic level. Dr. Seuntjens is also investigating the application and clinical translation of modulated electron radiation therapy as well as other clinically-inspired research topics in a collaborative context with other PIs. Dr. Seuntjens’ research is supported by the CIHR and NSERC.

  Recent publications:

  1. Devic S, Tomic N, Aldelaijan S, Deblois F, Seuntjens J, Chan M, Lewis D (2012) Linearization of dose–response curve of the radiochromic film dosimetry system Med. Phys. 39(8), 4850-4857.
  2. Alexander A, Soisson E, Renaud MA, Seuntjens J (2012) Direct aperture optimization for FLEC-based MERT and its application in mixed beam radiotherapy, Med. Phys. 39(8), 4820-4831.
  3. E. Conneely, A. Alexander, G. Stroian, Seuntjens J (2013) An investigation into the use of MMCTP to tune accelerator source parameters and testing its clinical application, J Appl Clin Med Phys 4(2); 3692.
  4. Tran, S. D., Liu, Y., Xia, D., Maria, O. M., Khalili, S., Wang, R. W-Y., Quan, V-H., Hu, S, and Seuntjens JP (2013) Paracrine effects of Bone Marrow Soup restore organ function, regeneration, and repair in salivary glands damaged by irradiation, PLoS One 24(8); e61632.
  5. Morin J, Béliveau-Nadeau D, Chung E, Seuntjens J, Thériault D, Archambault L, Beddar S, and Luc Beaulieu (2013) A comparative study of small field total scatter factors and dose profiles using plastic scintillation detectors and other stereotactic dosimeters: The case of the CyberKnife, Med. Phys. 40(1), 011719.
  6. Renaud J, Marchington D, Seuntjens JP, Sarfehnia A (2013) Development of a graphite probe calorimeter for absolute clinical dosimetry, Med Phys (Letters) 40(2) 020701-01-06.
  7. J Seuntjens, E Chung, E Soisson (2013) Reply to “Comment on ‘Dose homogeneity specification for reference dosimetry of nonstandard fields”, Med. Phys. 39, 407–414 (2012), Med Phys (Letters) 40(3) 037102.
  8. P Papaconstadopoulos, J Seuntjens (2013) A source model for modulated electron radiation therapy using dynamic jaw movements, Med. Phys. 40(5), 051707-1-051707-12.
  9. E Chung, S Davis, J Seuntjens (2013) Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams, Med. Phys. 40(6), 062104-1-062104-7.
  10. McEwen, L. DeWerd, G. Ibbott, D. Followill, D. W. O. Rogers, S. Seltzer, and J Seuntjens (2014) Addendum to the AAPM’s TG-51 Protocol for Clinical Reference Dosimetry of High-Energy Photon Beams, Med Phys 41:041501.
  11. H Bekerat, S. Devic, F. Deblois, K. Singh, A. Sarfhenia, J Seuntjens, S.Shih, X. Gyu, and D. Lewis (2014) Improving the Energy Response of External Beam Therapy (EBT) GAFCHROMIC™ Dosimetry Films at Low Energies (≥100 keV), Med Phys 41(2):022101. doi: 10.1118/1.4860157.
  12. Tomic N, Quintero C, Whiting BR, Aldelaijan S, Bekerat H, Liang L, DeBlois F, Seuntjens J, Devic S. (2014) Characterization of calibration curves and energy dependence GafChromic(TM) XR-QA2 model based radiochromic film dosimetry system. Med Phys. 41(6):062105. doi: 10.1118/1.4876295.
  13. Conneely E, Alexander A, Ruo R, Chung E, Seuntjens J., Foley MJ. (2014) Monte Carlo investigation of collapsed versus rotated IMRT plan verification. J Appl Clin Med Phys. 15(3):4681. doi: 10.1120/jacmp.v15i3.4681.
  14. Connell T, Alexander A, Papaconstadopoulos P, Serban M, Devic S, Seuntjens J, (2014) Delivery validation of an automated modulated electron radiotherapy plan. Med Phys. 41(6):061715. doi: 10.1118/1.4876297.
  15. Connell T, Seuntjens J, (2014) Design and validation of novel scattering foils for modulated electron radiation therapy. Phys Med Biol. 59(10):2381-91.
• 

  Luc Beaulieu

  • Title
    Professor & Director
  • Affiliation
    Department of Physics, Engineering Physics and at Université Laval
  • Phone
    418-656-2131 poste 3814
  • Email
    luc.beaulieu@phy.ulaval.ca
  • Website
    http://physmed.fsg.ulaval.ca/

  • Reasearch Keywords
  • Biography
  • Research Program
  • Publications

  Scintillation Fiber Dosimetry; Radiotherapy Physics; Brachytherapy Physics; Dose Calculations

  Luc Beaulieu received his PhD from Université Laval in 1996. After a postdoctoral fellowship in Berkeley, California, he worked as a research scientist at the Indiana University Cyclotron Facility in Bloomington. In 2000, he took the leadership of the medical physics research group at Quebec City University Hospital. Under his leadership, a formal graduate medical physics teaching curriculum was setGup and became CAMPEP accredited in 2011. Dr. Beaulieu is a full professor (tenured) at Université Laval and Director of the CAMPEP graduate program. He is a member of the AAPM Brachytherapy Subcommittee, of TGG192, was the Chair of TGG186 (published in 2012) and now leads the AAPM/ESTRO/ABG Working Group on ModelGBased Dose Calculations in brachytherapy. As of 2014, he has mentored more than 65 graduate students and postdoctoral fellows, published 169 peerGreviewed manuscripts and over 330 abstracts at national and international meetings. He is a recognized expert in scintillation dosimetry and brachytherapy.

  The ongoing objective of Prof. Beaulieu’s research program is to increase the accuracy of dose measurements and dose calculations for any radiation based procedures including, but not limited to, radiation therapy, diagnostic and interventional radiology. This is achieved through a comprehensive research program combining elements of basic and applied research in medical physics and biomedical engineering. The program hinges on radiation physics, optics, numerical optimization problems, image and signal processing and highGperformance computing. The program is subGdivided along four main research tracks, namely 1) development of new radiation dosimeters, 2) applied medical image processing, 3) numerical computation in optimization problems and high precision particle transport and dose calculations, and 4) a developing trac.

  Recent publications:

  1. White SA, Landry G, Fonseca GP, Holt R, Rusch T, Beaulieu L, Verhaegen F, Reniers B., Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source. Med Phys. 2014 Jun;41(6):061701.
  2. Afsharpour H, Walsh S, Collins Fekete CA, Vigneault E, Verhaegen F, Beaulieu L., On the sensitivity of α/β prediction to dose calculation methodology in prostate brachytherapy. Int J Radiat Oncol Biol Phys. 2014 Feb 1;88(2):345-50.
  3. Poulin E, Fekete CA, Létourneau M, Fenster A, Pouliot J, Beaulieu L. Adaptation of the CVT algorithm for catheter optimization in high dose rate brachytherapy. Med Phys. 2013 Nov;40(11):111724. doi: 10.1118/1.4826335.
  4. Lecavalier ME, Goulet M, Allen CN, Beaulieu L, Larivière D., Water-dispersable colloidal quantum dots for the detection of ionizing radiation. Chem Commun (Camb). 2013 Dec 25;49(99):11629-31.
  5. Desbiens M, D’Amours M, Afsharpour H, Verhaegen F, Lavallée MC, Thibault I, Vigneault É, Beaulieu L., Monte Carlo dosimetry of high dose rate gynecologic interstitial brachytherapy. Radiother Oncol. 2013 Dec;109(3):425-9.
  6. Goulet M, Archambault L, Beaulieu L, Gingras L., 3D tomodosimetry using long scintillating fibers: a feasibility study. Med Phys. 2013 Oct;40(10):101703.
  7. Mashouf S, Lechtman E, Beaulieu L, Verhaegen F, Keller BM, Ravi A, Pignol JP., A simplified analytical dose calculation algorithm accounting for tissue heterogeneity for low-energy brachytherapy sources. Phys Med Biol. 2013 Sep 21;58(18):6299-315.
  8. Guillot M, Gingras L, Archambault L, Beddar S, Beaulieu L.Performance assessment of a 2D array of plastic scintillation detectors for IMRT quality assurance. Phys Med Biol. 2013 Jul 7;58(13):4439-54.
  9. Therriault-Proulx F, Beddar S, Beaulieu L., On the use of a single-fiber multipoint plastic scintillation detector for 192Ir high-dose-rate brachytherapy. Med Phys. 2013 Jun;40(6):062101.
  10. Therriault-Proulx F, Beaulieu L, Archambault L, Beddar S., On the nature of the light produced within PMMA optical light guides in scintillation fiber-optic dosimetry. Phys Med Biol. 2013 Apr 7;58(7):2073-84.
  11. Morin J, Beliveau-Nadeau D, Chung E, Seuntjens J, Theriault D, Archambault L, Beddar S, Beaulieu L., A comparative study of small field total scatter factors and dose profiles using plastic scintillation detectors and other stereotactic dosimeters: the case of the CyberKnife. Med Phys. 2013 Jan;40(1):011719.
  12. Klein D, Briere TM, Kudchadker R, Archambault L, Beaulieu L, Lee A, Beddar S. In-phantom dose verification of prostate IMRT and VMAT deliveries using plastic scintillation detectors. Radiat Meas. 2012 Oct 1;47(10):921-929.
  13. Therriault-Proulx F, Archambault L, Beaulieu L, Beddar S. Development of a novel multi-point plastic scintillation detector with a single optical transmission line for radiation dose measurement. Phys Med Biol. 2012 Nov 7;57(21):7147-59.
  14. Archambault L, Therriault-Proulx F, Beddar S, Beaulieu L. A mathematical formalism for hyperspectral, multipoint plastic scintillation detectors. Phys Med Biol. 2012 Nov 7;57(21):7133-45.
  15. Beaulieu L, Carlsson Tedgren A, Carrier JF, Davis SD, Mourtada F, Rivard MJ, Thomson RM, Verhaegen F, Wareing TA, Williamson JF. Report of the Task Group 186 on model-based dose calculation methods in brachytherapy beyond the TG-43 formalism: current status and recommendations for clinical implementation. Med Phys. 2012 Oct;39(10):6208-36.
• 

  Malcolm McEwen

  • Title
    Adjunct Professor
  • Affiliation
    Ionising Radiation Standards, National Research Council of Affliation Canada
  • Phone
    (613) 993-2197 Ext. 226
  • Email
    Malcolm.McEwen@nrc-cnrc.gc.ca
  • Website
    http://www.nrc-cnrc.gc.ca/eng/education/innovations/scientists/mcewen.html

  • Reasearch Keywords
  • Biography
  • Research Program
  • Publications

  Radiation Physics and Dosimetry; Experiments; Detectors; Accelerators; Calorimeters

  Malcolm McEwen joined the Ionizing Radiations Standards Group at NRC in 2002 from the National Physical Laboratory in the UK. He has over 20 years experience in the field of ionizing radiation metrology and is actively involved with national and international organizations focusing on radiation dosimetry and medical physics including the Ottawa Medical Physics Institute, American Association of Physicists in Medicine and the Sistema Interamericano de Metrología. He is Adjunct Professor in the Department of Physics at Carleton University and participates in the medical physics graduate program there through supervision, teaching and providing access to NRC research facilities. Dr McEwen’s main area of interest is in the dosimetry for highGenergy photon and electron beams, as produced by linear accelerators and he has developed calibration services and protocols that enable medical physicists in cancer centres to deliver radiation therapy treatments with improved accuracy.

  Expertise:
  Development of primary standard calorimeters for highG energy photon and electron beam dosimetry at industrial and radiotherapy levels. Performance of secondary dosimeters G ionization chambers, diodes, chemical dosimeters (Fricke, alanine, etc). Operation of linear accelerators in the MeV energy range. Development of calibration services, codes of practice and audit systems for radiotherapy centres in Canada and worldwide.

  The Ionizing Radiation Standards Group is responsible for maintaining and developing measurement standards for Canada in the areas of radiation dosimetry and radioactivity. In addition to physical measurements it has a long history of developing radiation transport codes and maintains the wellG known EGSnrc system. The group has an impressive array of facilities including: CoG60, kV xGrays and betaGsource irradiation facilities, a lowGscatter radiation protection laboratory (with neutron and CsG137 beams), a comprehensive radioactivity and radiochemistry laboratory and a linear accelerator lab housing two MV electron linacs.

  Current and planned projects within the group include:
  •  Development of a primary standard water calorimeter for electron beam dosimetry.
  •  Investigation of dose standards for small photon beams.
  •  Evaluation of new ion chamber designs for reference dosimetry.
  •  Investigation of novel detectors for high accuracy applications in radiation dosimetry.
  •  Measurement of ‘fundamental’ parameters used in radiation dosimetry (e.g., stopping powers for electron beams, the average energy required to produce an ion pair in air)
  •  Application of the Fricke dosimeter system to brachytherapy and kV dosimetry
  •  Performance comparison of integrating dosimeters (e.g., alanine, OSL, radiochromic film) and application as secondary standard and/or audit dosimeters
  •  Development of standards for LDR brachytherapy
  •  Development of techniques to determine absolute activity of alpha, beta and gamma radioactive sources.
  •  Investigation of the production, extraction, standardization and delivery of diagnostic radionuclides.
  •  Measurement of the absolute neutron fluence and energy spectra of neutron sources.
  Projects are generally carried out in a team environment giving students the opportunity to work with several experts within the IRS group.

  Recent publications:

  1. McEwen M, DeWerd L, Ibbott G, Followill D, Rogers DW, Seltzer S, Seuntjens J., Addendum to the AAPM’s TG-51 protocol for clinical reference dosimetry of high-energy photon beams. Med Phys. 2014 Apr;41(4):041501. doi: 10.1118/1.4866223.
  2. Bouchard H, McEwen M., Comment on “linearization of dose-response curve of the radiochromic film dosimetry system” [Med. Phys. 39(8), 4850-4857 (2012)]. Med Phys. 2012 Nov;39(11):7171-2; author reply 7173-4. doi: 10.1118/1.4762820.
  3. Lacroix F, Guillot M, McEwen M, Gingras L, Beaulieu L., Extraction of depth-dependent perturbation factors for silicon diodes using a plastic scintillation detector. Med Phys. 2011 Oct;38(10):5441-7. doi: 10.1118/1.3637496.
  4. Lacroix F, Guillot M, McEwen M, Cojocaru C, Gingras L, Beddar AS, Beaulieu L., Extraction of depth-dependent perturbation factors for parallel-plate chambers in electron beams using a plastic scintillation detector. Med Phys. 2010 Aug;37(8):4331-42.
  5. McEwen MR., Measurement of ionization chamber absorbed dose k(Q) factors in megavoltage photon beams. Med Phys. 2010 May;37(5):2179-93.
  6. Tessier F, Hooten BD, McEwen MR., Zero-shift thimble ionization chamber. Med Phys. 2010 Mar;37(3):1161-3.
  7. Devic S, McEwen MR, Orton CG., Point/counterpoint. Radiochromic film is superior to ion chamber arrays for IMRT quality assurance. Med Phys. 2010 Mar;37(3):959-61. No abstract available.
  8. Faddegon BA, Sawkey D, O’Shea T, McEwen M, Ross C., Treatment head disassembly to improve the accuracy of large electron field simulation. Med Phys. 2009 Oct;36(10):4577-91.
  9. La Russa DJ, McEwen M, Rogers DW., An experimental and computational investigation of the standard temperature-pressure correction factor for ion chambers in kilovoltage x rays. Med Phys. 2007 Dec;34(12):4690-9.
  10. McEwen M, Palmans H, Williams A., An empirical method for the determination of wall perturbation factors for parallel-plate chambers in high-energy electron beams. Phys Med Biol. 2006 Oct 21;51(20):5167-81. Epub 2006 Sep 27.
  11. McEwen M., Comment on “determination of the depth of 50% of maximum ionization, I50, for electron beams by the divided difference method” [med. phys. 31, 2068-2074 (2004)]. Med Phys. 2004 Nov;31(11):3158-9; author reply 3160.
• 

  Philippe Després

  • Title
    Assistant Professor
  • Affiliation
    Department of Physics, Engineering Physics and Optics at Université Laval
  • Phone
    418-656-2131 poste 2511
  • Email
    philippe.despres@phy.ulaval.ca
  • Website
    http://www.physmed.fsg.ulaval.ca

  • Reasearch Keywords
  • Biography
  • Research Program
  • Publications

  Image Processing; X-ray; CT; PET; SPECT; GPU Processing

  Philippe Després is an Assistant Professor in the Department of Physics, Engineering Physics and Optics at Université Laval and a Medical Physicist at CHU de Québec. He was trained at Université Laval (MSc 2000, Physics), Université de Montréal (PhD 2005, Physics) and University of California, San Francisco (postdoc 2005G2007, Biomedical Engineering, Molecular Imaging).   He has been involved in numerous projects encompassing hardware and software aspects of medical imaging modalities such as XGray, CT, PET and SPECT. He has worked on lowGdose XGray imaging (scanningGslit xenon microstrip detector), advanced imaging techniques (multiG energy XGray imaging), and solidGstate detectors for molecular imaging (PSAPD and CZTGbased PET and SPECT). He also has developed highGperformance computing approaches with commodity graphics hardware (GPUs) that have led to innovative applications in image processing/reconstruction and radiation dose calculation, including a fast GPUGbased Monte Carlo engine to simulate energy transport in matter. He holds grants from NSERC, CIHR, FRQGS and has established research collaborations with numerous industrial and academic partners both locally and abroad.

  The research program pursued by Prof. Després is geared towards the use of highGperformance computing to tackle problems in Medical Physics. Specifically, physicsGrich models are used to reach better, more accurate solutions in a variety of clinical situations. These physicsGrich models however are numerically challenging and usually require large computing resources. As these problems are often intrinsically parallel, they can be implemented on Graphics Processing Units (GPUs) and benefit from their massively parallel architecture (hundreds of cores per processor). Therefore, the numerical burden of realistic modeling is alleviated by the use of GPUs; acceleration factors of 10 to 1000x have been achieved with this technology compared to traditional CPU implementations. This level of performance lets envision the clinical deployment of better solutions in radiation dose calculation and tomographic image reconstructionG. In the first case, a fast GPUG based Monte Carlo engine was developed to simulate the transport of energy in matter. This allows for more accurate dose calculations in external beam radiation therapy, brachytherapy, radiology and nuclear medicine while maintaining calculation times that are compatible with a clinical workflow. In tomographic image reconstruction, GPUG accelera ed iterative algorithms integrating physicsGbased priors have been developed to achieve fewGviews, lowGdose or artefact suppressing solutions.
  In PET and SPECT molecular imaging, efforts are invested in the development of a quantitative imaging platform. An automatic blood activity counter is being developed to monitor the amount of radiotracer available for uptake as a function of time in order to feed pharmacokinetic models and extract valuable physiological information from imaging studies.

  Recent publications:

  1. Lucas-Hourani M, Munier-Lehmann H, Helynck O, Komarova A, Desprès P, Tangy F, Vidalain PO. High-throughput Screening for Broad-spectrum Chemical Inhibitors of RNA Viruses. J Vis Exp. 2014 May 5;(87).
  2. Tangy F, Desprès P., Yellow fever vaccine attenuation revealed: loss of diversity. J Infect Dis. 2014 Feb 1;209(3):318-20.
  3. La Ruche G, Dejour-Salamanca D, Bernillon P, Leparc-Goffart I, Ledrans M, Armengaud A, Debruyne M, Denoyel GA, Brichler S, Ninove L, Desprès P, Gastellu-Etchegorry M., Capture-recapture method for estimating annual incidence of imported dengue, France, 2007-2010. Emerg Infect Dis. 2013 Nov;19(11):1740-8.
  4. Lernout T, Cardinale E, Jego M, Desprès P, Collet L, Zumbo B, Tillard E, Girard S, Filleul L., Rift valley fever in humans and animals in Mayotte, an endemic situation? PLoS One. 2013 Sep 30;8(9):e74192. doi: 10.1371/journal.pone.0074192.
  5. Lucas-Hourani M, Dauzonne D, Jorda P, Cousin G, Lupan A, Helynck O, Caignard G, Janvier G, André-Leroux G, Khiar S, Escriou N, Desprès P, Jacob Y, Munier-Lehmann H, Tangy F, Vidalain PO., Inhibition of pyrimidine biosynthesis pathway suppresses viral growth through innate immunity. PLoS Pathog. 2013;9(10):e1003678. doi: 10.1371/journal.ppat.1003678. Epub 2013 Oct 3.
  6. Gandini M, Gras C, Azeredo EL, Pinto LM, Smith N, Despres P, da Cunha RV, de Souza LJ, Kubelka CF, Herbeuval JP., Dengue virus activates membrane TRAIL relocalization and IFN-α production by human plasmacytoid dendritic cells in vitro and in vivo. PLoS Negl Trop Dis. 2013 Jun 6;7(6):e2257. doi: 10.1371/journal.pntd.0002257. Print 2013.
  7. Larrieu S, Cardinale E, Ocquidant P, Roger M, Lepec R, Delatte H, Camuset G, Desprès P, Brottet E, Charlin C, Michault A., A fatal neuroinvasive West Nile virus infection in a traveler returning from Madagascar: clinical, epidemiological and veterinary investigations. Am J Trop Med Hyg. 2013 Aug;89(2):211-3.
  8. Brandler S, Ruffié C, Combredet C, Brault JB, Najburg V, Prevost MC, Habel A, Tauber E, Desprès P, Tangy F., A recombinant measles vaccine expressing chikungunya virus-like particles is strongly immunogenic and protects mice from lethal challenge with chikungunya virus. Vaccine. 2013 Aug 12;31(36):3718-25.
  9. Bahuon C, Desprès P, Pardigon N, Panthier JJ, Cordonnier N, Lowenski S, Richardson J, Zientara S, Lecollinet S., IS-98-ST1 West Nile virus derived from an infectious cDNA clone retains neuroinvasiveness and neurovirulence properties of the original virus. PLoS One. 2012;7(10):e47666. doi: 10.1371/journal.pone.0047666. Epub 2012 Oct 23.
  10. Lucas-Hourani M, Lupan A, Desprès P, Thoret S, Pamlard O, Dubois J, Guillou C, Tangy F, Vidalain PO, Munier-Lehmann H., A phenotypic assay to identify Chikungunya virus inhibitors targeting the nonstructural protein nsP2. J Biomol Screen. 2013 Feb;18(2):172-9.
  11. Nassiri MA, Hissoiny S, Carrier JF, Després P., Fast GPU-based computation of the sensitivity matrix for a PET list-mode OSEM algorithm. Phys Med Biol. 2012 Oct 7;57(19):6279-93.
  12. Lessard F, Archambault L, Plamondon M, Despres P, Therriault-Proulx F, Beddar S, Beaulieu L., Validating plastic scintillation detectors for photon dosimetry in the radiologic energy range. Med Phys. 2012 Sep;39(9):5308-16.
  13. Henrik Gad H, Paulous S, Belarbi E, Diancourt L, Drosten C, Kümmerer BM, Plate AE, Caro V, Desprès P., The E2-E166K substitution restores Chikungunya virus growth in OAS3 expressing cells by acting on viral entry. Virology. 2012 Dec 5;434(1):27-37.
  14. Hissoiny S, D’Amours M, Ozell B, Despres P, Beaulieu L., Sub-second high dose rate brachytherapy Monte Carlo dose calculations with bGPUMCD. Med Phys. 2012 Jul;39(7):4559-67.
  15. Seuntjens J, Beaulieu L, El Naqa I, Després P. Special section: Selected papers from the Fourth International Workshop on Recent Advances in Monte Carlo Techniques for Radiation Therapy. Phys Med Biol. 2012 Jun 7;57(11). doi: 10.1088/0031-9155/57/11/E01.
• 

  Slobodan Devic

  • Title
    Assistant Professor
  • Affiliation
    McGill University, Medical Physics Unit
  • Phone
    514-340-8222 x2595
  • Email
    slobodan.devic@mcgill.ca
  • Website
    http://www.mcgill.ca/medphys/

  • Reasearch Keywords
  • Biography
  • Research Program
  • Publications

  Radiochromic Flim Dosimetry; Brachytherapy Physics; PET Imaging in Radiotherapy

  Slobodan Devic obtained his M.Sc. degree in nonGideal plasma physics and his Ph.D. degree in Solid State Physics in 1997 at the University of Belgrade, Serbia. He moved to the USA in 1998 where he worked as a Research Associate in Radiation Oncology Physics at the Mallinckrodt Institute of Radiology, St. Louis, Missouri. Subsequently, he moved in 2000 to the Montreal General Hospital and McGill University where he was enrolled into the Medical Physics Residency program. Upon finishing his residency in 2002 he joined the Medical Physics Unit at the McGill University and, in 2008, he moved to his current position at the SMBD Jewish General Hospital in Montreal. He is a Fellow of the Canadian College of Physicists in Medicine and his major research interests are radiochromic film dosimetry and its applications, image guided brachytherapy with particular interest in preGoperative endorectal brachytherapy, and the incorporation of the functional imaging information into radiotherapy treatment planning process. Dr. Devic is also teaching Physics in Nuclear Medicine course at the McGill University and as of 2009 he became a member of the Editorial board of the Medical Physics journal.

  Research program of Slobodan Devic revolves around:

  1. radiochromic film dosimetry,
  2. implementation of MRI and functional imaging for radiotherapy treatment planning,
  3. preGoperative endorectal brachytherapy
  4. design and output verification of radiobiological experiments

  Recent publications:

  1. Tomic N, Quintero C, Whiting BR, Aldelaijan S, Bekerat H, Liang L, DeBlois F, Seuntjens J, Devic S. (2014) Characterization of calibration curves and energy dependence GafChromic(TM) XR-QA2 model based radiochromic film dosimetry system. Med Phys. 2014 Jun;41(6):062105. doi: 10.1118/1.4876295
  2. H Bekerat, S. Devic, F. Deblois, K. Singh, A. Sarfhenia, J Seuntjens, S.Shih, X. Gyu, and D. Lewis (2014) Improving the Energy Response of External Beam Therapy (EBT) GAFCHROMIC™ Dosimetry Films at Low Energies (≥100 keV), Med Phys 41(2):022101. doi: 10.1118/1.4860157.
  3. Han DY, Webster MJ, Scanderbeg DJ, Yashar C, Choi D, Song B, Devic S, Ravi A, Song WY. Direction-Modulated Brachytherapy for High-Dose-Rate Treatment of Cervical Cancer. I: Theoretical Design. nt J Radiat Oncol Biol Phys. 2014 Apr 18. pii: S0360-3016(14)00284-3. doi: 10.1016/j.ijrobp.2014.02.039. [Epub ahead of print].
  4. Mujica-Mota MA, Lehnert S, Devic S, Gasbarrino K, Daniel SJ. Mechanisms of radiation-induced sensorineural hearing loss and radioprotection. Hear Res. 2014 Jun;312C:60-68. doi: 10.1016/j.heares.2014.03.003. Epub 2014 Mar 18. Review.
  5. Mujica-Mota MA, Devic S, Daniel SJ. The relevance of dosimetry in animal models of cochlear irradiation. Otol Neurotol. 2014 Apr;35(4):704-11.
  6. Mujica-Mota MA, Salehi P, Devic S, Daniel SJ. Safety and otoprotection of metformin in radiation-induced sensorineural hearing loss in the Guinea pig. Otolaryngol Head Neck Surg. 2014 May;150(5):859-65.
  7. Webster MJ, Devic S, Vuong T, Han DY, Scanderbeg D, Choi D, Song B, Song WY. HDR brachytherapy of rectal cancer using a novel grooved-shielding applicator design. Med Phys. 2013 Sep;40(9):091704. doi: 10.1118/1.4816677.
  8. Webster MJ, Devic S, Vuong T, Yup Han D, Park JC, Scanderbeg D, Lawson J, Song B, Tyler Watkins W, Pawlicki T, Song WY. Dynamic modulated brachytherapy (DMBT) for rectal cancer. Med Phys. 2013 Jan;40(1):011718. doi: 10.1118/1.4769416.
  9. S. Devic ” MRI simulation for radiotherapy treatment planning” Med Phys. 2012 Nov;39(11):6701-11.
  10. Ahmad S, Devic S, Orton CG. ” Point/Counterpoint: PET-based GTV definition is the future of radiotherapy treatment planning.” Med Phys. 2012 Oct; 39(10):5791-4.
  11. Devic S, Tomic N, Aldelaijan S, Deblois F, Seuntjens J, Chan MF, Lewis D. Linearization of dose-response curve of the radiochromic film dosimetry system. Med Phys. 2012 Aug;39(8):4850-7.
  12. Heravi M, Tomic N, Liang L, Devic S, Holmes J, Deblois F, Radzioch D, Muanza T. Sorafenib in combination with ionizing radiation has a greater anti-tumour activity in a breast cancer model, Anticancer Drugs. 2012 Jun;23(5):525-33.
  13. Arjomandy B, Tailor R, Zhao L, Devic S. EBT2 film as a depth-dose measurement tool for radiotherapy beams over a wide range of energies and modalities, Med Phys. 2012 Feb;39(2):912-21.
  14. Aldelaijan S, Mohammed H, Tomic N, Liang LH, Deblois F, Sarfehnia A, Abdel-Rahman W, Seuntjens J, Devic S. Radiochromic film dosimetry of HDR (192)Ir source radiation fields, Med Phys. 2011 Nov;38(11):6074-83.
  15. Boivin J, Tomic N, Fadlallah B, Deblois F, Devic S. Reference dosimetry during diagnostic CT examination using XR-QA radiochromic film model, Med Phys. 2011 Sep;38(9):5119-29.

SCIENTISTS

• 

  Harald Paganetti

  Radiation Physics; Monte Carlo Simulations in Proton Therapy
• 

  Jan Seuntjens

  Radiation Physics and Dosimetry; Monte Carlo Calculations; Calorimetry; Detectors; Small Fields
• 

  Luc Beaulieu

  Scintillation Fiber Dosimetry; Radiotherapy Physics; Brachytherapy Physics; Dose Calculations
• 

  Malcolm McEwen

  Radiation Physics and Dosimetry; Experiments; Detectors; Accelerators; Calorimeters
• 

  Philippe Després

  Image Processing; X-ray; CT; PET; SPECT; GPU Processing
• 

  Slobodan Devic

  Radiochromic Flim Dosimetry; Brachytherapy Physics; PET Imaging in Radiotherapy