Current Fellows in the Radiation Epidemiology Branch
Pragati Gole Advani, M.D., Dr.P.H., M.P.H. – Postdoctoral Fellow
Learn about REB research training opportunities.
Pragati Gole Advani, M.D., Dr.P.H., M.P.H. joined the Radiation Epidemiology Branch (REB) as a Cancer Research Training Award postdoctoral fellow in November 2017. Dr. Advani earned her doctoral degree from the University of Texas, School of Public Health in May 2016 with a major in health promotion and behavioral sciences and minor in cancer epidemiology. During her doctoral program, she served as a Susan G. Komen pre-doctoral fellow and her dissertation examined disparities in patient adherence to surgical management of breast cancer and survivorship practices at the MD Anderson Cancer Center (MDACC). During the last year, Dr. Advani served as a first-year postdoctoral fellow in the Division of Radiation Oncology at the MDACC, where she worked on a population-based study examining the burden of local therapy (surgery and radiation) decisions and associated outcomes among older breast cancer patients. In May 2011, Dr. Advani earned her M.P.H from the Western Kentucky University with a concentration in health education and leadership studies. In October 2008, she earned her degree in medicine from University of Seychelles. At the REB, Dr. Advani is working with Lindsay Morton, Ph.D., senior investigator, to broaden her experience in cancer survivorship research by investigating the etiolof treatment-related second cancers.
David Borrego, Ph.D. – Independent Research Scholar
David Borrego, Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in June 2016. He became a research fellow and was named an NIH Independent Research Scholar in 2019. Dr. Borrego earned a B.S. in nuclear and radiological engineering (2010) and both an M.S. (2012) and Ph.D. (2016) in biomedical engineering with a concentration in medical physics from the University of Florida. His doctoral dissertation work focused on assessment of organ doses for fluoroscopically guided interventional procedures. Dr. Borrego’s main research interest are in Monte Carlo estimation of organ doses for patients undergoing radiography and fluoroscopy examinations as well as organ dose reconstruction based on occupational radiation exposure in a study of US radiologic technologists. In REB, Dr. Borrego is working closely with Choonsik Lee, Ph.D., investigator, REB, Martha Linet, M.D., M.P.H., senior investigator, REB, and Cari Kitahara, Ph.D., M.H.S., investigator, on estimating organ and tissue specific absorbed doses for use in epidemiological studies and in particular to members of the United States Radiologic Technologist Cohort. See Dr. Borrego's biography page to learn more about his research.
Yingxi (Cimo) Chen, M.D., Ph.D. – Postdoctoral Fellow
Yingxi (Cimo) Chen, M.D., Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in September 2017. Dr. Chen received a bachelor’s degree in medicine (2011) from the Sichuan University and an M.P.H. (Res) (2013) and Ph.D. in epidemiology (2017) from the Australian National University. For her dissertation research, Dr. Chen estimated the burden of gastrointestinal infections in middle-aged and older adults, and investigated factors that were associated with adverse clinical outcomes using linked data from a large-scale cohort study to multiple administrative and clinical databases. In the Radiation Epidemiology Branch, Dr. Chen is working with Amy Berrington de González, D.Phil., Chief and senior investigator, REB, on several projects with the goal of evaluating trends in disease incidence and mortality data.
Konstantin Chizhov, Ph.D. – Postdoctoral Fellow
Konstantin Chizhov, Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in December 2019. Dr. Chizhov received an M.S. in radiation physics from the Moscow Engineering Physical Institute, Russia, in 2009 and a Ph.D. in radiobiology from the State Research Center—Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency (SRC–FMBC), in 2019. As a senior researcher, he has 10 years of experience in the regulatory supervision of projects for the Andreeva Bay nuclear legacy site. In REB, Dr. Chizhov will work with Choonsik Lee, Ph.D., Dosimetry Unit Head and senior investigator, and Elizabeth K. Cahoon, Ph.D., Earl Stadtman Tenure-track Investigator, on his postdoctoral research, which focuses on radiation dosimetry for studies of the Chernobyl accident and atomic bomb survivors. Dr. Chizhov’s research interests include dose reconstruction and assessment methods. He has received numerous awards for his work, including the Bernard Wheatley Award, Early Stage Radiation Investigators Award, and European Radiation Research Society Young Investigator Award.
Keith T. Griffin, M.S. – Predoctoral Fellow
Keith T. Griffin, M.S., joined the Radiation Epidemiology Branch (REB) as a predoctoral fellow in June 2017. He earned both his B.S. (2015) and M.S. (2016) in nuclear and radiological engineering from the Georgia Institute of Technology in Atlanta. Previously, Mr. Griffin worked two summers with the Center for Radiation Protection Knowledge team at Oak Ridge National Laboratory as an intern. As part of his core research interests, he has employed Monte Carlo computational simulations to calculate organ absorbed doses associated with dozens of environmental and medical external exposures. Recently Mr. Griffin returned to school to earn a doctorate degree from Georgia Tech in nuclear engineering with a minor concentration in medical physics. At NCI, he is working under the mentorship of Choonsik Lee, Ph.D., senior investigator, REB, to help establish the computational dosimetry methods needed for future epidemiological studies of proton therapy on a patient-specific basis.
Jim Mai, M.D., M.P.H., Ph.D. – Postdoctoral Fellow
Jim Zhi-Ming Mai, M.D., M.P.H., Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in June 2019. Dr. Mai completed his clinical training, received master degrees in epidemiology and biostatistics, and obtained a Ph.D. in cancer epidemiology from The University of Hong Kong (HKU). Working with Prof. TH Lam, Dr. Mai was a Senior Technical Officer at HKU, where he conducted a multicenter nasopharyngeal carcinoma case-control study and analyzed the pooled prospective cohort studies to examine the associations of cancer risk with several environmental factors including sunlight, vitamin D, Epstein-Barr virus, and quitting smoking. His research interest is in ultraviolet radiation (UVR) exposure (mainly from sunlight). Under the primary mentorship of Elizabeth Cahoon, Ph.D., Earl Stadtman Investigator, REB, Dr. Mai is working on multidisciplinary studies of UVR exposure, photosensitizing medications, oncoviruses infection/activation, and cancer risk among SEER participants, U.S. radiologic technologists and Medicare recipients.
Cody Ramin, Ph.D. – Postdoctoral Fellow
Cody Ramin, Ph.D., joined the Radiation Epidemiology Branch (REB) as a Cancer Prevention Fellow in September 2018. Dr. Ramin earned her Ph.D. in epidemiology from the Johns Hopkins Bloomberg School of Public Health in 2018 and her M.S. in epidemiology from the Harvard T.H. Chan School of Public Health in 2013. Dr. Ramin’s research interests focus on breast cancer etiology and the role of cancer therapy on second cancer risk and cardiovascular disease among breast cancer survivors. Dr. Ramin is working with Amy Berrington de González, D.Phil., Chief and senior investigator, REB, and Gretchen Gierach, Ph.D., M.P.H., Deputy Chief and senior investigator, Integrative Tumor Epidemiology Branch, on studies to advance our understanding of contralateral breast cancer.
André Rose, M.D., Ph.D. – Postdoctoral Fellow
André Rose, M.D., Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in March 2019. Dr. Rose earned his medical degree from the University of the Witwatersrand (Johannesburg, South Africa) in 1999 and his Ph.D. in epidemiology and medical physics from the University of the Free State (Bloemfontein, South Africa) in 2018. While at the University of the Free State, he worked with Prof. William Rae and focused on radiation-induced cataracts and radiation safety practices in a catheterization laboratory. Dr. Rose’s research interests include occupational radiation safety and occupational radiation epidemiology. In REB, Dr. Rose is working with Cari Kitahara, Ph.D., investigator, REB, to explore risks associated with work history practices, including radiation safety, among nuclear medicine technologists, and long-term health risks in medical radiation workers more broadly.
Daphnée Villoing, Ph.D. – Research Fellow
Daphnée Villoing, Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in April 2016. Dr. Villoing received an M.Sc. in biomedical engineering (2010), an M.Sc. in medical physics (2011), and a Ph.D. in medical physics (October 2015) from Paul Sabatier University, Toulouse, France. Her doctoral dissertation work was focused on the impact of the Monte Carlo code GATE on imaging and dosimetric calculations for targeted radionuclide therapy. Dr. Villoing’s main research interests are Monte Carlo modelling, dosimetry of ionizing radiation in medical imaging and radiation therapy, radiation protection, and computational anthropomorphic models for medical imaging and radiation therapy. In REB, Dr. Villoing is working on the calculation of organ doses to patients who underwent diagnostic nuclear medicine procedures from the early 1960s to the present, under the supervision of Choonsik Lee, Ph.D., and Vladimir Drozdovitch, Ph.D. She is also involved in the evaluation of historical trends for occupational doses received by participants in the U.S. Radiologic Technologists Study and the U.S. Nuclear Medicine Technologists Pilot Study from 1960-2010, under the supervision of Cari Kitahara, Ph.D. Another component of her postdoctoral work is to estimate uncertainty and to increase dosimetric accuracy for organ doses for patients who underwent nuclear medicine procedures, using Monte Carlo radiation transport coupled with computational human phantoms, under Dr. Lee’s supervision.
Jacqueline B. Vo, Ph.D., R.N., M.P.H. – Postdoctoral Fellow
Jacqueline B. Vo, Ph.D., R.N., M.P.H., joined the Radiation Epidemiology Branch (REB) as a Cancer Prevention Fellow in September 2019. Dr. Vo earned her B.S. in nursing from the University of Alabama at Birmingham (UAB) in 2014. After graduation, she worked as a cardiac intensive care nurse at UAB Hospital from 2014 to 2016. Dr. Vo completed a Ph.D. in nursing science at UAB in 2018, where she studied breast cancer survivorship under the mentorship of Dr. Karen Meneses. During her Ph.D. training, Dr. Vo was a Robert Wood Johnson Future of Nursing Scholar, Susan G. Komen Graduate Trainee in Disparities Research, and recipient of the American Cancer Society Doctoral Degree Scholarship in Cancer Nursing. Her dissertation research focused on cardiovascular disease risk among young breast cancer survivors, and her research interests span cancer treatment-induced cardiotoxicity, young breast cancer survivorship needs, and cancer-related cognitive impairment. In May of 2019, Dr. Vo earned an M.P.H. in quantitative methods from the Harvard T.H. Chan School of Public Health. In REB, Dr. Vo is working with Amy Berrington de González, D.Phil., Branch Chief and senior investigator, to examine the impact of cancer treatment on cardiovascular morbidity and mortality among breast cancer survivors and to characterize trends in cardiovascular disease mortality among adult-onset cancer survivors in the U.S.
Diana Withrow, Ph.D. – Research Fellow
Diana Withrow, Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in May 2016 and promoted to Research Fellow in June 2018. Dr. Withrow earned her Ph.D. in epidemiology from the University of Toronto Dalla Lana School of Public Health in 2016. Working with Dr. Loraine Marrett, her doctoral research comprised the first national-level analysis of cancer survival among First Nations and Métis adults in Canada. In 2010, Dr. Withrow earned an M.Sc. in epidemiology from the London School of Hygiene and Tropical Medicine. Dr. Withrow’s research interests include socio-demographic and economic disparities in survival and survivorship, the role of therapy on second cancer risk, and the optimal application of survival analysis techniques to these research areas. At NCI, Dr. Withrow is working with Amy Berrington de González, D.Phil., Chief and senior investigator, REB, and Lindsay Morton, Ph.D., senior investigator, REB. Dr. Withrow is currently working on several projects with the goal of characterizing patterns in second cancer incidence, particularly among breast cancer survivors.
Yeon Soo Yeom, Ph.D. – Postdoctoral Fellow
Yeon Soo Yeom, Ph.D., joined the Radiation Epidemiology Branch (REB) as a postdoctoral fellow in March 2018. Dr. Yeom earned his B.S. (2011) and Ph.D. (2017) in nuclear engineering from Hanyang University, Seoul, South Korea, where he subsequently served as a postdoctoral researcher prior to joining REB. During his doctoral and postdoctoral training at Hanyang University, working with Prof. Chan Hyeong Kim, Dr. Yeom developed new adult male and female mesh-type reference computational phantoms for the International Commission on Radiological Protection (ICRP). Currently, Dr. Yeom is a full member on the International Commission of Radiological Protection (ICRP) Task Group 103 and a corresponding member on the ICRP Task Group 90. In REB, Dr. Yeom is working with Choonsik Lee, Ph.D., head of the Dosimetry Unit and senior investigator, REB, to expand his research experience to dosimetry studies for radiation epidemiology focusing on dose reconstruction for proton therapy patients.