Update Your ProfileAcademic Title:
Professor
Primary Appointment:
Radiation Oncology
Administrative Title:
Vice Chair of Medical Physics
Location:
UMMC GGK19
Education and Training
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University of Mumbai, Mumbai, India |
B.E.(Hons.) |
1996 |
Biomedical Engineering |
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University of Tennessee, Tennessee, U.S.A. |
M.S. |
1999 |
Biomedical Engineering |
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University of Michigan, Michigan, USA |
Ph.D. |
2006 |
Biomedical Engineering |
Biosketch
I am a medical physicist and an imaging scientist. My research interests focus on developing and translating novel forms of image-guidance in radiation therapy, specifically in the area of stereotactic ablative radiotherapy (SAbR), also known as SBRT. The overall goal of our research is to fundamentally improve the understanding, diagnosis, and treatment of cancer through pre-clinical and clinical investigations and translation of novel forms of cancer imaging, radiobiologic agents and precision radiotherapy
Research/Clinical Keywords
Small animal IGRT, precision radiotherapy, motion management, stereotactic body radiotherapy, SBRT
Highlighted Publications
- A. Modiri, X. Gu, A. Hagan, R. Bland, P. Iyengar, R. Timmerman, A. Sawant, " Inverse 4D conformal planning for lung SBRT using particle swarm optimization," Phys Med Biol. 2016 Aug 21;61(16):6181-202.
- D. Moore, D. Ruan, A. Sawant, "Fast leaf-fitting with generalized underdose/overdose constraints for real-time MLC tracking," Med Phys 43, 465 (2016)
- A. Modiri, X. Gu, A. Hagan, A. Sawant, "Radiotherapy Planning Using an Improved Search Strategy in Particle Swarm Optimization," IEEE Trans Biomed Eng (2016).
- W. Liu, A. Sawant, D. Ruan, "Prediction of high-dimensional states subject to respiratory motion: a manifold learning approach," Phys Med Biol 61, 4989-4999 (2016).
- T.J. Arai, J. Nofiele, A.J. Madhuranthakam, Q. Yuan, I. Pedrosa, R. Chopra, A. Sawant, "Characterizing spatiotemporal information loss in sparse-sampling-based dynamic MRI for monitoring respiration-induced tumor motion in radiotherapy," Med Phys 43, 2807 (2016).
- Y. Cheung, A. Sawant, "An externally and internally deformable, programmable lung motion phantom," Med Phys 42, 2585-2593 (2015).
- A. Sawant, P. Keall, K.B. Pauly, M. Alley, S. Vasanawala, B.W. Loo, Jr., J. Hinkle, S. Joshi, "Investigating the feasibility of rapid MRI for image-guided motion management in lung cancer radiotherapy," Biomed Res Int 2014, 485067 (2014).
- A. Sawant, S. Dieterich, M. Svatos, P. Keall, "Failure mode and effect analysis-based quality assurance for dynamic MLC tracking systems," Med Phys 37, 6466-6479 (2010).
- A. Sawant, R.L. Smith, R.B. Venkat, L. Santanam, B. Cho, P. Poulsen, H. Cattell, L.J. Newell, P. Parikh, P.J. Keall, "Toward submillimeter accuracy in the management of intrafraction motion: the integration of real-time internal position monitoring and multileaf collimator target tracking," Int J Radiat Oncol Biol Phys 74, 575-582 (2009).
- A. Sawant, R. Venkat, V. Srivastava, D. Carlson, S. Povzner, H. Cattell, P. Keall, "Management of three-dimensional intrafraction motion through real-time DMLC tracking," Med Phys 35, 2050-2061 (2008)
Research Interests
Small Animal Image-Guided Radiotherapy – One of the most exciting developments in pre-clinical radiotherapy research has been the introduction and increased adoption of small animal image-guided radiotherapy (SA-IGRT) platforms. Compared to traditional pre-clinical irradiation systems, which have rudimentary dose delivery capabilities, little or no treatment planning, SA-IGRT systems are designed with capabilities that are routinely used in clinical radiotherapy – 3D imaging, inverse planning and advanced dose delivery. Our group has several research programs developed around the SARRP system (XStrahl), with the overarching goal of translating pre-clinical findings into future clinical studies. Our major areas of research include (a) the development of orthotopic tumor models in mice and rats for prostate, lung and pancreatic cancer; (b) investigations of thermally-modulated radiotherapy to sensitize tumor tissue and protect normal tissue (thereby widening the therapeutic window) and (c) investigations of advanced imaging techniques to spatially map post-radiotherapy inflammation in lung stereotactic body radiotherapy (SBRT).
Next-Generation Motion Management – Accounting for temporal anatomic changes in thoracic and abdominal cancer radiotherapy is one of the key scientific and clinical challenges of our era. These anatomic changes reduce image quality and targeting accuracy, which in turn lead to geometric and dosimetric errors. Such errors become increasingly important as we move toward hypofractionated regimens such as stereotactic ablative radiotherapy (SABR), where highly potent doses are administered to the tumor target in few fractions. Thoracic anatomy changes in all four dimensions (4D=3D+time) from cycle-to-cycle and day-to- day. A common limitation of current motion management techniques is that they discard large amounts of this 4D information and do not capture nor adequately account for cycle-to-cycle variations. The goal of our motion management research is to capture and account for all four dimensions at each RT step – simulation, treatment planning and dose delivery.
We use high-performance CPU and GPU computing to (a) create patient-specific, parameterized volumetric motion models that describe the underlying patient anatomy as a function of optical surface over many breathing cycles, (b) investigate higher-order inverse planning strategies using GPU-based swarm optimization algorithms to create truly 4D-optimized treatment plans that use motion as an additional degree of freedom in the optimization process and (c) real-time motion tracking using a dynamic multileaf collimator (MLC) which reshapes the beam so as to follow all of the complex changes (translation, rotation and deformation) of the tumor and surrounding organs.
Awards and Affiliations
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2004 |
First place in the John R. Cameron Young Investigator Competition at the 2004 AAPM annual meeting for oral presentation entitled "Empirical Investigation of a New Generation of High QE Detectors for Active Matrix Flat-Panel Imager EPIDs" |
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2006 |
Nominated for the University of Michigan, Rackham School’s Distinguished Dissertation Award. |
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2007 |
Second place in the Young Investigator Competition at the XVth ICCR meeting (2007) in Toronto, Canada, for oral presentation entitled "A Generalized Method for 3D Tracking of Intrafraction Tumor Motion Using a Dynamic Multileaf Collimator" |
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2008 |
ASTRO 2008 Basic Science Research Grant Award for presentation entitled “Geometric Accuracy and Latency of an Integrated 4D IMRT Delivery System using Real-Time Internal Position Monitoring and Dynamic MLC Tracking” |
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2010 |
Selected for The John S. Laughlin Science Council Research Symposium at the 2010 AAPM annual meeting for oral presentation entitled "Real-Time MRI for Soft-Tissue-Based IGRT of Moving and Deforming Lung Tumors" |
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2014 |
Selected for the BEST IN PHYSICS (Therapy) category at the 2014 AAPM annual meeting for oral presentation entitled “4D IMRT Planning Using Highly-Parallelizable Particle Swarm Optimization” |
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2015 |
Selected for the BEST IN PHYSICS category at the 2015 ASTRO annual meeting for oral presentation entitled “Dose Response Relationship for Stereotactic Ablative Body Radiation Therapy Associated Airway Collapse.” |
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2016 |
Selected for the BEST IN PHYSICS (Joint Imaging-Therapy) category at the 2016 AAPM annual meeting for oral presentation entitled “An MRI Compatible Externally and Internally Deformable Lung Motion Phantom for Multi-Modality IGRT” |
Grants and Contracts
Active/Pending Grants:
09/01/13 - 06/30/18 (PI: 40%)
“Personalized Motion Management for truly 4D Lung Stereotactic Body Radiotherapy”
NIH R01CA169102
Annual Direct Costs: $378,562
Total Direct Costs: $2,006,669
08/01/16 - 07/31/21 (PI: 35%)
“Investigating Radiation Injury to Airways and Pulmonary Vasculature in Lung SAbR”
NIH R01 CA202761-01
Annual Direct Costs: $497,740
Total Direct Costs: $2,488,701
Completed Grants:
02/01/15-01/30/17 (PI: 3%)
“Dynamic MLC tracking using real-time Vision RT-based guidance for lung SBRT”
VisionRT
Annual Direct Costs: $51,000 (indirects were waived)
Total Direct Costs: $102,000
12/01/12-11/30/15 (PI: 30%)
“Comprehensive Four-Dimensional Motion-Adaptive Lung SBRT”
Varian Medical Systems
Annual Direct Costs: $100,747
Total Direct Costs: $402,985
Professional Activity
2014-present Vice Chair, Task Group TG 264 - Safe Clinical Implementation of MLC Tracking in Radiotherapy, American Association of Physicists in Medicine (AAPM)
2015 Organizer and Co-Moderator, “Academic-Industrial Research and Development Partnerships-Nuts and Bolts, Pitfalls and Rewards”, American Association of Physicists in Medicine (AAPM) 2015 Annual Meeting. Session selected as AAPM President’s choice for the year’s conference theme-Reinvigorating Scientific Excellence
2016-present Member, Research Committee, AAPM
2016-present Member, Imaging for Treatment Verification Work Group, AAPM
2016-present Member, Editorial board, Medical Physics Journal