Medical Physics Education Program
A certificate and accreditation program for Dartmouth postdocs and PhD students
Ramish Ashraf PhD Candidate – Stanford Medical Physics Residency 2021
Rachael Hachadorian PhD – Harvard Medical Physics Residency 2021
Benjamin Maloney PhD Candidate – Henry Ford Medical Center - Imaging Physics Residency 2021
Boyu Meng PhD Candidate – UT Southwestern Medical Physics Residency 2021
PhD Candidate Rachael Hachadorian won the recent Nature Communications Essay content for early career applicants, associated with publications in the journal. Read all about her experiences here. Also find her scientific publication in the journal (Nature Comm. 11, 2298, 2020) here. She also successfully defended her PhD thesis on Friday March 19, 2021!
Three Dartmouth researchers involved in radiotherapy work have been accepted into the Early Career Investigator Symposium competition, in the American Association of Physicists in Medicine (AAPM) Spring Clinical Meeting. PhD Candidates Mahbubur 'Ronny' Rahman and Daniel Alexander will present along with Thayer Research Scientist Brady Hunt PhD. The three talks are all at the start of the program, linked here:
| SA-B-Therapy Saturday | ||
| 12:30 PM | Clinical Treatment Planning System for Electron FLASH Radiotherapy
Mahbubur Rahman |
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| 12:40 PM | MR-Linac Isocenter Coincidence Verification Using Cherenkov Imaging
Daniel Alexander MS |
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| 12:50 PM | Gantry Motion Artifact Reduction Using Deep Learning: Towards Volumetric Modulated Arc Therapy On MR-Linacs
Brady Hunt PhD |
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In a study by Medical Physics PhD Candidate, Brook K Byrd, the three-dimensional shape of breast cancer was examined for the first time in a comprehensive study of 83 patients using supine MRI. As they describe, "implicit to approaches that localize the center of the tumor for breast-conserving surgery (BCS) of non-palpable cancers is the assumption that breast cancers are spherical about a central point, which may not be accurate." The team found that cancers could be categorized into four tumor shapes, with 34% discoidal, 29% segmental, 19% spherical & 18% irregular. They found that they could use these tumor shape models to better inform surgery, and potentially allow more precise resection. The work was published in Breast Cancer Research and Treatment Sept 2020. DOI: 10.1007/s10549-020-05780-6
A recent study by Rachael Hachadorian and colleagues in Nature Communications (DOI https://doi.org/10.1038/s41467-020-16031-z), showed how the intensity of Cherenkov light coming from patients getting whole breast radiotherapy was affected by the tissue present. The CT scans of each patient were used to calibrate for attenuation of the light for fibroglandular versus adipose tissue variations, as a surrogate for blood based attenuation. The group showed that the calibrated Cherenkov was closer to a true representation of the average dose delivered to the breast, paving the initial step towards quantitative remote dose imaging in vivo.
Rachael Hachadorian, PhD candidate 2021
A ‘FLASH’ ultra-high dose rate radiation therapy beam was initiated in New England for the first time, demonstrating that it can be achieved reversibly on a clinical linear accelerator, and deliver the beam in a standard patient geometry. The work was Reported in the IJROBP paper by PhD students Mahbubur Rahman and Ramish Ashraf (DOI: 10.1016/j.ijrobp.2021.01.011).
Mahburbur Rahman H. Ramish Ashraf
The work was done at the Norris Cotton Cancer Center (NCCC) by a joint team of researchers led by Professors David Gladstone, Rongxiao Zhang and Benjamin Williams from the Division of Radiation Oncology within the Department of Medicine, PhD students Ronny Rahman and Ramish Ashraf at the Thayer School of Engineering as well as Professors Petr Bruza and Brian Pogue, and Professor Jack Hoopes in the Department of Surgery, at Dartmouth-Hitchcock Medical Center in Lebanon NH. Pilot funding from the NCCC and Thayer provided the team with the capability to prototype how to convert linac to this exceptionally high dose rate of 300 Gray per second, whereas normal therapy treatment is done at 0.1 Gray per second. Instead of treatment over 20 seconds, an entire treatment is completed in 6 milliseconds. These high dose rates have been shown to protect normal tissues from excess damage while still having the same treatment effect on tumor tissues, and so may be critically important for limiting radiation damage in patients receiving radiation therapy. The work was reported Aug 16 2020 in the online arXiv publication arXiv:2008.06980 [physics.med-ph]. The team developed the beam for pre-clinical testing future human translational studies.
Head of Clinical Physics, David J. Gladstone Sc.D. has been elected as a Fellow of the American Association of Physics in Medicine (AAPM) at the annual meeting in July 2020.
Election to Fellowship in the AAPM signifies that the recipient has demonstrated excellence in Leadership to the Profession, Service to the AAPM, Research and Scholarly Work, or Teaching and Mentoring. The award of 'Fellow' designation is a significant honor within the society, indicating their work at the highest level of both their career work and to importance to the society.
Irwin I. Tendler PhD graduate of the Dartmouth Medical Physics Education Program received the highly competitive 1st Prize in the Young Investigator Symposium of the American Association of Physicists in Medicine (AAPM) Annual Meeting (virtual) 2020.
His work on the characterization of Cherenkov light from the human eye during radiation therapy as described by both in vivo measurements as well as ex vivo validation studies. The full description is written up in the International Journal of Radiation Oncology, Biology & Physics 2020 (https://www.redjournal.org/article/S0360-3016(19)33947-1/abstract).
Dr Tendler is a 1st year Medical Physics resident at the M. D. Anderson Cancer Center, in Houston TX.
The AAPM Annual virtual meeting is a forum for many students and researchers within the Dartmouth Medical Physics Education Program, and a sweep of awards show the excellence, with 6 Blue Ribbon ePosters, 1 Young Investigator Talk, 3 additional talks and 3 additional posters!
Blue Ribbon Prize ePosters
Imaging Dose in Breast Radiotherapy by X-Ray CT Calibration of Cherenkov Light
Rachael Hachadorian, et al
Session Title: Multi-Disciplinary Blue Ribbon ePoster: BReP-SNAP-M-87
Imaging Proton Pencil Beam Scans & Depth Dose Profiles with An Optimized Scintillation Screen & High Frame Rate Camera
Mahbubur Rahman, et al.
Session Title: Therapy Blue Ribbon ePoster: BReP-SNAP-T-77
Total Skin Electron Therapy Treatment Planning and Dose Distribution Verification Using Cherenkov Imaging and Computer Animation Techniques
T Miao, et al
Session Title: Multi-Disciplinary Blue Ribbon ePoster: BReP-SNAP-M-141
High Resolution Optical Imaging of 4 & 5 Millimeter Beams: A Small Field Dosimetry Technique
Muhamad Ashraf, et al
Session Title: Therapy Blue Ribbon ePoster: BReP-SNAP-T-74
Real Time Plan Verification of Radiotherapy Treatment Plans Using Couch and Gantry Mounted Cameras
Muhumad Ashraf, et al,
Session Title: Therapy Blue Ribbon ePoster: BReP-SNAP-T-119
Rapid commissioning of an MR-Linac with Hydrostatic and Cherenkov Imaging Techniques
Rongxiao Zhang, et al
Session Title: Multi-Disciplinary Blue Ribbon ePoster: BReP-SNAP-M-123
Talks
First-time imaging of Light Generation in the Eye During Radiotherapy
Irwin Tendler, et al
Session Title: John R. Cameron YOUNG INVESTIGATOR SYMPOSIUM
Session Number: MO-CD-TRACK 1-2
First Imaging of Intrinsic Light Emission from Biological Tissue Visualized Proton Pencil Beam Scanning
P Bruza, et al,
Session Title: Imaging for Particle Therapy
Session Number: MO-E-TRACK 2-3
Date: 07/13/2020 Session Time: 03:30PM - 04:30PM
Scintillation Imaging for 2D Beam Characterization and Output Measurement for MR-Linac Quality Assurance
D Alexander, et al,
Session Title: MRI in Radiotherapy
Session Number: TU-EF-TRACK 2-14 (last number indicates order within session)
Date: 07/14/2020 Session Time: 03:30PM - 05:30PM
Treatment Verification from Cherenkov Imaging During Radiation Therapy
B Pogue, et al,
Session Title: Thunder and Light(ning): Applications and Potential of Radiation Acoustics and Optics
Session Number: SU-CD-TRACK 3-5
Date: 07/12/2020 Session Time: 01:00PM - 03:00PM
ePosters
Evaluating the Clinical Utility of Cherenkov Imaging in Radiotherapy
R Hachadorian, et al,
Session Title: Multi-Disciplinary General ePoster
Poster Number: PO-GeP-M-194
Automated Detection of Field Match Lines Between Supraclavicular and
Tangent Irradiation Fields with Cherenkov Imaging
R Hachadorian, et al
Session Title: Multi-Disciplinary General ePoster PO-GeP-M-75
Estimated Linear Energy Transfer and Depth Dose Profiles Through Combined Radioluminescence Imaging & Monte Carlo Calculation
M Rahman, et al,
Session Title: Therapy General ePoster: PO-GeP-T-388
Efficient Acquisition of MR-Linac Commissioning Data Using Cherenkov Projection Imaging
D Alexander, et al,
Session Title: Multi-Disciplinary General ePoster PO-GeP-M-183
Monitoring tumour progression during a course of radiation therapy can help determine whether a treatment is working or not. Such tracking is mostly anatomy-based, using weekly CT scans, for example, to measure tumour size. This approach, however, can fail to detect subtle changes at the cellular level – a task that calls for functional imaging.
Functional imaging modalities can characterize responses of the tumour microenvironment. But common techniques, such as PET or diffusion-weighted MRI, require a separate scheduled exam. Researchers from Dartmouth College’s Thayer School of Engineering have now proposed a way to image the tumour microenvironment during radiotherapy without interrupting the clinical workflow, using Cherenkov-excited luminescence imaging (CELI). They achieve this by employing CELI to track the spread of a phosphorescent tattoo ink (Phys. Med. Biol. 10.1088/1361-6560/ab7d16)
