Enhancing Radiation Therapy Through Cherenkov Light-Activated Phototherapy.


This work investigates a new approach to enhance radiotherapy through a photo therapeutic agent activated by Cherenkov light produced from the megavoltage photon beam. The process is termed Radiotherapy Enhanced with Cherenkov photo-Activation (RECA). RECA is compatible with various photo-therapeutics, but here we focus on use with psoralen, an ultraviolet activated therapeutic with extensive history of application in superficial and extracorporeal settings. RECA has potential to extend the scope of psoralen treatments beyond superficial to deep seated lesions.In vitro studies in B16 melanoma and 4T1 murine breast cancer cells were performed to investigate the potential of RT plus RECA versus RT alone for increasing cytotoxicity (local control) and increasing surface expression of major histocompatibility complex I (MHC I). The latter represents potential for immune response amplification (increased antigen presentation), which has been observed in other psoralen therapies. Cytotoxicity assays included luminescence and clonogenics. The MHC I assays were performed using flow cytometry. In addition, Cherenkov light intensity measurements were performed to investigate the possibility of increasing the Cherenkov light intensity per unit dose from clinical megavoltage beams, to maximize psoralen activation.Luminescence assays showed that RECA treatment (2 Gy at 6 MV) increased cytotoxicity by up to 20% and 9.5% for 4T1 and B16 cells, respectively, compared with radiation and psoralen alone (ie, Cherenkov light was blocked). Similarly, flow cytometry revealed median MHC I expression was significantly higher in RECA-treated cells, compared with those receiving radiation and psoralen alone (approximately 450% and 250% at 3 Gy and 6 Gy, respectively, P << .0001). Clonogenic assays of B16 cells at doses of 6 Gy and 12 Gy showed decreases in tumor cell viability of 7% (P = .017) and 36% (P = .006), respectively, when Cherenkov was present.This work demonstrates for the first time the potential for photo-activation of psoralen directly in situ, from Cherenkov light generated by a clinical megavoltage treatment beam.






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Publication Info

Yoon, Suk W, Vadim Tsvankin, Zachary Shrock, Boyu Meng, Xiaofeng Zhang, Mark Dewhirst, Peter Fecci, Justus Adamson, et al. (2018). Enhancing Radiation Therapy Through Cherenkov Light-Activated Phototherapy. International journal of radiation oncology, biology, physics, 100(3). 10.1016/j.ijrobp.2017.11.013 Retrieved from https://hdl.handle.net/10161/16475.

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Mark Wesley Dewhirst

Gustavo S. Montana Distinguished Professor Emeritus of Radiation Oncology

Mark W. Dewhirst, DVM, PhD is the Gustavo S. Montana Professor of Radiation Oncology and Vice Director for Basic Science in the Duke Cancer Institute. Dr. Dewhirst has research interests in tumor hypoxia, angiogenesis, hyperthermia and drug transport. He has spent 30 years studying causes of tumor hypoxia and the use of hyperthermia to treat cancer. In collaboration with Professor David Needham in the Pratt School of Engineering, he has developed a novel thermally sensitive drug carrying liposome that has been successfully translated to human clinical trials. He has utilized the thermal characteristics of this liposome to develop an MR imageable form that can accurately reflect drug concentrations in tumors, which then is related to the extent of anti-tumor effect in pre-clinical models. This property has been widely used by other investigators, world-wide, particularly in the area of high intensity focused ultrasound, where it would be possible to literally paint drug to a target zone and visualize this process in real time, during heating. For his work in this area, Dr. Dewhirst was named a Fellow in the AAAS. Dr. Dewhirst has well over 500 peer-reviewed publications, book chapters and reviews, with >20,000 citations and an H-index of 73. He has given named lectures at the University of Western Ontario, Thomas Jefferson University and the New Zealand Cancer Society. He was awarded the Failla Medal and Lecture at the Radiation Research Society in 2008, the Eugene Robinson award for excellence hyperthermia research in 1992 and a similar award from the European Society for Hyperthermic Oncology in 2009. He was named a fellow of ASTRO in 2009 and was awarded the prestigious Gold Medal from the same society in 2012. He is a Senior Editor of Cancer Research and Editor-in-Chief of the International Journal of Hyperthermia. He has mentored 24 graduate students, and many postdoctoral fellows, residents, junior faculty and medical students. He has been particularly skillful in assisting those he has mentored to obtain DOD and NIH fellowships, K awards and first R01 grants. His skill in mentoring has been recognized by the Duke Comprehensive Cancer Center, the Medical Physics Graduate Training programs and the School of Medicine, where he has received “Mentor of the Year” awards. In 2011 he was selected to become the first Associate Dean of Faculty Mentoring in the Duke School of Medicine. In this position, he is implementing a comprehensive program to enhance success in obtaining NIH funding. He graduated from the University of Arizona in 1971 with a degree in Chemistry and Colorado State University in 1975 and 1979 with DVM and PhD degrees, respectively.


Peter Edward Fecci

Professor of Neurosurgery

As the Director of both the Brain Tumor Immunotherapy Program and the Center for Brain and Spine Metastasis at Duke University, I focus our programmatic interests on the design, optimization, and monitoring of immune-based treatment platforms for patients with intracranial tumors, whether primary or metastatic. Within this broad scope, however, my own group looks more specifically at limitations to immunotherapeutic success, with a particular focus on understanding and reversing T cell dysfunction in patients with glioblastoma (GBM) and brain metastases. We employ a systematic approach to categorizing T cell dysfunction (Woroniecka et al, Clin Cancer Res 2018 Aug 15;24(16):3792-3802), and whereas our earlier work addressed concerns for regulatory T cell-induced tolerance, we now heavily study T cell ignorance and exhaustion, as well. Regarding the former, we recently published the novel phenomenon of S1P1-mediated bone marrow T cell sequestration in patients with intracranial tumors (Chongsathidkiet et al, Nat Medicine 2018 Sep;24(9):1459-1468). Regarding the latter, we have likewise recently identified and characterized exhaustion as a significant limitation to T-cell function within GBM (Woroniecka et al, Clin Cancer Res 2018 Sep 1;24(17):4175-4186). I very much look to collaboratively integrate our approaches with others investigating innovative treatment options. I continue my focus on combining strategies for reversing T cell deficits with current and novel immune-based platforms as a means of deriving and improving rational and precise anti-tumor therapies. It is my sincerest desire to forge a career focused on co-operative, multi-disciplinary, organized brain tumor therapy. Ultimately, my goal is to help coordinate the efforts of a streamlined and effective center for brain tumor research and clinical care. I hope to play some role in ushering in a period where the science and treatment arms of brain tumor therapy suffer no disjoint, but instead represent the convergent efforts of researchers, neuro-oncologists, medical oncologists, radiation oncologists, biomedical engineers, and neurosurgeons alike. I hope to see such synergy become standard of care.


Justus D Adamson

Associate Professor of Radiation Oncology

Radiosurgery and SBRT
Image Guided Radiation Therapy (IGRT)
Quality Assurance (QA) in Radiation Therapy
3D Dosimetry


Mark Oldham

Professor of Radiation Oncology

Dr Oldham is the Director of the Duke Medical Physics MS/PhD Graduate Program, and Professor in the Department of Radiation Oncology, with a secondary appointment in the Physics Department at Duke. 

Main current research interests include: FLASH radiation therapy, exploring FLASH mechanisms utilizing the Duke High Intensity Gamma Source (HIGS), a nuclear research accelerator on the Duke campus.  Recent work selected for best in Physics at the annual AAPM meeting.  Radiation and Immunotherapy utilizing mini-grids. Radiation Therapy Enhanced by Cherenkov photo-Activation (RECA) and Comprehensive 3D dosimetry.

Dr Oldham has patented and published on several novel radiation treatment techniques (including XPACT and RECA - Radiotherapy Enhanced by Cherenkov photo-Activation) with exiting potential to invoke systemic anti-cancer immunogenic response.  A phase I clinical trial of XPACT is underway.  The lab has pioneered novel pre-clinical treatment capabilities including mini-beam grids, and ultra-high-resolution IMRT.  The lab has also developed novel optical imaging techniques for high-resolution 3D imaging of vascular networks and fluorescent gene expression in un-sectioned tissue samples.

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