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Erik J. Tryggestad, PhD, DABR

Phone number: (410) 955-7391


Clinical and research interests: Motion management in radiotherapy; 4D treatment planning; 4D-MRI; Stereotactic radiosurgery and radiotherapy; Kilovoltage radiation dosimetry

Title: Assistant Professor of Medical Physics

Schools\degrees: Wittenberg University, Springfield, OH\BA, Physics, 1996; Michigan State University, East Lansing, MI\ PhD, Nuclear Physics, 2001; ABR certified, Therapeutic Radiotherapy Physics

Training: Centre Nationale de la Recherche Scientifique, Institute de Physique Nucléaire d’Orsay. Orsay, France\Post-Doctoral Fellowship, Nuclear Physics, 2002-2004; Johns Hopkins University School of Medicine, Department of Radiation Oncology and Molecular Radiation Sciences, Baltimore MD\Post-Doctoral Fellowship, Medical Physics, 2004-2006)

Research summary: I was educated and trained as an experimental nuclear physicist at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. My Ph.D. thesis involved the elucidation of a theorized collective dipole excitation in an exotic isotope of oxygen, 20O. Following my time at MSU, I completed a two-year post-doctoral fellowship at the Institut de Physique Nucléaire (IPN) d’Orsay (France) where I conducted further research probing the resonant structure of the 9He via the (d,p) reaction with a 8He beam at the Grand Accélérateur National d’Ions Lourds (GANIL) facility in France.

During my fellowship training as a medical physicist at Johns Hopkins, I contributed to a highly successful, NIH-supported effort to build a novel, image-guided small-animal irradiator (SARRP; PI: J. Wong). The principle aim of this project was to bridge the technological gap that exists between the cruder radiation techniques used in the pre-clinical setting and modern clinical radiotherapy. My main area of focus related to this project was and continues to be kilovoltage radiation dosimetry. I devised a system for dosimetric commissioning and validation using both Monte Carlo and measurement and, consequently, developed expertise in “micro” radiochromic film dosimetry. I currently employ this expertise to commission new small animal irradiators and support novel kilovoltage treatment planning initiatives ongoing at Johns Hopkins and elsewhere.

Also as a fellow, I played a leadership role in developing and implementing our program for breath-held radiotherapy delivery (using the Active Breathing Coordinator Device, Elekta Ltd.). This experience helped to foster a broader interest in respiratory motion. I have since begun a translational research program to incorporate deformable image registration into “4D” treatment planning with the aim of sparing normal tissue from unnecessary radiation exposure during passively-delivered, free breathing radiotherapy treatments. Limitations of conventional 4D imaging (“4D-CT”) in this context provided a strong impetus for my most recent translational research project to develop dynamic magnetic resonance imaging techniques for use for radiotherapy planning and guidance.

Clinically, I play a leadership role in the quality assurance of our image-guided linear accelerators and stereotactic procedures. In particular, I have been instrumental in designing our treatment protocols for image-guided stereotactic body radiotherapy. For example, I played a strong role in the design of the image-guided therapy portion of a multi-institutional trial to evaluate the efficacy of stereotactic body radiotherapy in pancreatic patients, which is currently enrolling patients at Johns Hopkins, Stanford, and Memorial Sloan Kettering.

Journal citations (medical physics only)

Karikari CA, Roy I, Tryggestad E, Feldmann G, Pinilla C, Welsh K, Reed JC, Armour EP, Wong J, Herman J, Rakheja D, Maitra A. Targeting the apoptotic machinery in pancreatic cancers using small-molecule antagonists of the X-linked inhibitor of apoptosis protein. Mol Cancer Ther. 2007; 6(3): 957-66.

Deng H, Kennedy CW, Armour E, Tryggestad E, Ford E, McNutt T, Jiang L Wong JW. The small-animal radiation research platform (SARRP): dosimetry of a focused lens system.  Phys. Med. Biol. 2007; 52: 2729.

Duan W, Peng Q, Masuda N, Ford E, Tryggestad E, Ladenheim B, Zhao M, Cadet JL, Wong JW, Ross CA. Sertraline slows disease progression and increases neurogenesis in N171-82Q mouse model of Huntington’s Disease.  Neurobiol. Dis. 2008; 30: 312.

Wong J, Armour E, Kazanzides P, Iordachita I, Tryggestad E, Deng H, Kennedy C, Liu Z, Chan T, Gray O, Verhaegan F, McNutt T, Ford E, DeWeese TL. A high resolution small animal radiation research platform (SARRP) with x-ray tomographic guidance capabilities. Int. J. Rad. Onc. Biol. Phys.2008; 71(5): 1591-9.

Ford E, Purger D, Tryggestad E, McNutt T, Christodouleas J, Rigamonti D, Shokek O, Won S, Zhou J, Lim M, Wong J, Kleinberg L. A virtual frame system for stereotactic radiosurgery planning. Int J Radiat Oncol Biol Phys. 2008; 72(4): 1244-9.

Tryggestad E, Armour M, Iordachita I, Verhaegen F, Wong JW. A comprehensive system for dosimetric commissioning and Monte Carlo validation for the Small Animal Radiation Research Platform. Phys Med. Biol. 2009; 54(17): 5341-57.

Tryggestad E, Christian M, Ford E, Kut C, Le Y, Sanguineti G, Song DY and Kleinberg L. Inter- and intra-fraction patient positioning uncertainties for intra-cranial radiotherapy: a study of four frameless, thermoplastic mask-based immobilization strategies using daily cone-beam CT. Int J Radiat Oncol Biol Phys. 2011; 80(1): 281-90.

Zhou J, Tryggestad E, Wen Z, Lal B, Zhou T, Grossman R, Wang S, Yan K,  Fu D, Blakeley J, Ford E, Tyler B, Laterra J and van Zijl PCM. Differentiation between glioma and radiation necrosis using molecular magnetic resonance imaging of endogenous proteins and peptides. Nat Med. 2011; 17(1): 130-4.

Cao X, Wu X, Frassica D, Yu B, Pang L, Xian L, Wan M, Lei W, Armour M, Tryggestad E, Wong J, Wen CY, Lu WW, Frassica FJ. Irradiation induces bone injury by damaging bone marrow microenvironment for stem cells. Proc Natl Acad Sci U S A. 2011; 108(4): 1609-14.

Redmond KJ, Achanta P, Grossman SA, Armour M, Reyes J, Kleinberg L, Tryggestad E, Quinones-Hinojosa A, Ford EC. A radiotherapy technique to limit dose to neural progenitor cell niches without compromising tumor coverage. J Neurooncol. 2011; In press.

Verhaegen F, Granton P, Tryggestad E. Small animal radiotherapy research platforms. Phys Med Biol. 2011; 56(12): R55-83.

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