Todd Powell
President and Chief Executive Officer
Member, Board of Directors
GET TO KNOW OUR TEAM
Our leadership team embodies experts who know that our success rides on the shoulders of our team members and advisors. They are solely focused on creating a world-class team working together to beat cancer.
Samuel Mazin, Ph.D.
Founder and Chief Technology Officer
Member, Board of Directors
Martyn Webster
Chief Financial Officer
Thorsten Melcher, Ph.D.
Chief Business Officer
Shervin 'Sean' Shirvani, M.D.
Chief Medical Officer
Philip J. Aulson II
Senior Vice President of Operations and Service
David Larkin
Senior Vice President of Research and Development
Kathy O’Shaughnessy, Ph.D.
Senior Vice President and Executive Advisor
Judy Bartlett-Roberto
Vice President of Marketing
Jeff Holifield, J.D.
Vice President, Head of Legal
Leonard Lyons
Vice President of Sales
Todd Powell
President and Chief Executive Officer
Member, Board of Directors
Todd Powell joined RefleXion in May 2017 as president, chief executive officer and a member of its board of directors, bringing with him 29 years of experience in leading global organizations and developing innovative products in cancer care. Before joining RefleXion, Powell spent 11 years at Elekta AB, a world leader in radiation oncology solutions where he held senior executive roles of increasing responsibility, most recently as executive vice president of Comprehensive Oncology Solutions where he led a business unit with more than $1 billion in revenue and 1,200 employees across North America, Europe and Asia. Prior to this, Powell served as president and CEO for IMPAC Medical Systems, Inc. His career also includes senior executive and management positions at IMPAC and Varian Medical Systems. Powell received a Bachelor of Applied Science, Physics and Mathematics from California State University, Chico, and he completed the Executive Innovation and Leadership Programs at Stanford University Graduate School of Business.
Samuel Mazin, Ph.D.
Founder and Chief Technology Officer
Member, Board of Directors
Sam Mazin, Ph.D., co-founded RefleXion Medical in 2009 where he is the inventor of the company’s core technology. While a postdoctoral researcher in Radiology at Stanford University, Dr. Mazin was selected by the Kauffman Foundation as one of 13 postdocs in the nation to commercialize promising innovations. His prior research at Stanford was focused on the design of a novel X-ray computed tomography (CT) system, resulting in several journal papers and a patent, as well as the Joel Drillings Award from the American Heart Association (AHA). His work on a PET-based algorithm received the prestigious Cum Laude award from the SPIE international medical imaging society. He has been invited to speak about biology-guided radiotherapy by cancer centers worldwide. Dr. Mazin received a Bachelor of Applied Science in Computer Engineering from the University of Waterloo, Canada, and he holds a Ph.D. in Electrical Engineering from Stanford University.
Martyn Webster
Chief Financial Officer
Martyn Webster joined RefleXion in July 2018 as chief financial officer with over 25 years of finance, accounting and leadership experience in medical device startups and other small businesses. His financial experience spans 30 countries and he has led teams of up to 70 people. Most recently, he was the CFO of Vital Connect, and before that he served as the chief accounting officer at Intermune prior to its acquisition by Roche. RefleXion is the sixth Silicon Valley life-science startup at which Webster has held senior level positions, with four of the previous five successfully scaling to achieve over $11B in combined exit returns. Webster received a Bachelor of Arts in History from Nottingham University, and he received his ACA Qualification from the Institute of Chartered Accountants in England. He received his MBA from Santa Clara University and he is a CPA in California.
Thorsten Melcher, Ph.D.
Chief Business Officer
Thorsten Melcher, Ph.D., joined RefleXion in July 2019 as chief business officer with over 25 years of experience in biotechnology and pharmaceutical business development. Most recently, Dr. Melcher served as CBO for Xyphos Biosciences, a startup developing next-generation CAR-T products. Previously, he served as senior director of new ventures at J&J where he championed business development projects focusing on therapeutics in oncology and neuroscience. Dr. Melcher was also vice president at Varian Medical where he developed a strategy to integrate radiotherapy with diagnostics and therapeutics to improve combination cancer treatment. His other past tenures include co-founding three biotech companies. Dr. Melcher received a Master of Science in Biochemistry from the University of Hannover and he holds a Ph.D. in Molecular Biology from Heidelberg University. He completed postdoctoral research in Molecular Biology at the University of California, San Francisco, and was previously on RefleXion’s scientific advisory board.
Shervin 'Sean' Shirvani, M.D.
Chief Medical Officer
Shervin ‘Sean’ Shirvani, M.D., joined RefleXion as vice president of medical affairs in July 2018 and was promoted to senior vice president of clinical and medical affairs in August 2019, and then to chief medical officer in December 2020. He contributes over 16 years of clinical and industry experience, including as a faculty radiation oncologist and medical director at MD Anderson Cancer Center’s Arizona affiliate. Dr. Shirvani previously served as a physician executive for Banner Medical Group, one of the nation’s largest multi-specialty groups, where he oversaw operations for multiple specialties including medical oncology. He also led the design and implementation of a value-based, alternative payment insurance product for cancer care for the country’s fifth largest metropolitan area. Dr. Shirvani has authored numerous publications, national practice guidelines, and book chapters on stereotactic radiotherapy and healthcare economics. He holds a Bachelor of Arts in Philosophy and a Bachelor of Science in Physics from Rice University. He received his MD from Duke University and a Master’s in Public Health from the University of Texas, Houston. He is dual board certified after completing residencies in Internal Medicine at Stanford University Medical Center and Radiation Oncology at MD Anderson Cancer Center.
Philip J. Aulson II
Senior Vice President of Operations and Service
Phil Aulson joined RefleXion in June 2016 as director of new product introduction and was promoted to vice president of operations and service in February 2019. In July 2023, he was promoted to senior vice president of operations and service, where he and his organization continue to keep the customer and their patients at the forefront while driving industry-leading output with the manufacture, installation, acceptance, and uptime of RefleXion’s X1 platform and SCINTIX technology. His previous experience includes over 20 years of leading medical device manufacturing operations for both Fortune 500 and startup organizations. Before joining RefleXion, Aulson was vice president of operations at Oraya Therapeutics. He has also held senior management positions at Insound Medical, Hansen Medical, Boston Scientific, Teleflex Medical and Depuy/Johnson & Johnson. Aulson received a Bachelor of Science in Mechanical Engineering from Northeastern University and his MBA from Babson College.
David Larkin
Senior Vice President of Research and Development
David Larkin joined RefleXion in 2014 as vice president of research and development, bringing over 25 years of experience in engineering leadership in the fields of medical robotic systems, mechatronics and control systems. He was promoted to senior vice president of research and development in August 2019. Prior to RefleXion, Larkin spent 14 years building and leading R&D teams at Intuitive Surgical (ISI), most recently as vice president of engineering. During his time at ISI, Larkin brought numerous breakthrough products in robotic assisted minimally invasive surgery into the clinic, culminating in ISI’s next generation, single-port robotic surgery platform. Before developing medical robotic systems, Larkin was president of MotionIO, a networked motion control startup, and prior to this, he was director of controls at Adept Technology. Larkin received a Bachelor of Science in Mechanical Engineering from Brown University, a Master of Science in Electrical Engineering and a Master of Science in Mechanical Engineering, both from Stanford University. Larkin is a named inventor on 91 patents.
Kathy O’Shaughnessy, Ph.D.
Senior Vice President and Executive Advisor
Since joining RefleXion in 2016 as vice president of regulatory and quality, Kathy O’Shaughnessy has been an integral part of the executive management team demonstrating exceptional leadership and expertise within quality and regulatory affairs. She led the team that secured the company’s first U.S. FDA clearance for RefleXion’s X1 platform for radiotherapy in 2021 and more recently the breakthrough SCINTIX therapy via the De Novo pathway. O’Shaughnessy currently serves as senior vice president and executive advisor, a promotion she received in July 2023. Her prior experience includes significant accomplishments in quality, clinical and regulatory, guiding 510(k) and PMA medical devices through the regulatory process in the U.S. and globally. Before joining RefleXion, O’Shaughnessy was vice president of clinical, regulatory, and quality for Miramar Labs (acquired by Sientra). Her past tenures also include senior-level executive positions in clinical and regulatory affairs at Allux Medical, Xoft (acquired by iCAD), and R2 Technology (acquired by Hologic). O’Shaughnessy received a Bachelor of Science in Physics and Math from the University of Victoria, Canada, a Master of Science in Physics, and a Ph.D. in Physics, both from Stanford University.
Judy Bartlett-Roberto
Vice President of Marketing
Judy Bartlett-Roberto joined RefleXion in September 2018 bringing 25 years of medical device industry expertise in commercializing disruptive technologies. She led marketing teams that successfully launched technologies resulting in changes to standard of care in electrophysiology, interventional cardiology, robotics and ophthalmology. Most recently, she held the position of vice president of marketing at Optovue, a precision ophthalmology imaging company. Prior to this, she spent 11 years as an independent consultant providing strategic marketing for a wide variety of Silicon Valley medical device startups. Her previous tenures also include executive positions at Hansen Medical, Cervel Neurotech and Siemens Medical, formerly Acuson. Bartlett-Roberto received a Bachelor of Science in Nursing from California State University, Chico, and her MBA, Marketing and Management from Santa Clara University.
Jeff Holifield, J.D.
Vice President, Head of Legal
Jeff Holifield joined RefleXion in November of 2020 as vice president and head of legal with over 25 years of experience in the technology sector, including expertise in SaaS licensing, cloud-based services, marketing partnerships, regulatory compliance and manufacturing/supply chain issues. Most recently, he was associate general counsel for Nutanix, a cloud computing company. At Nutanix, Jeff led the legal transition from a hardware model to subscription. His previous tenures include positions at Microsoft, Ericsson, Sun Microsystems, Sony Electronics and CenturyLink where he directed legal services across both consumer and enterprise businesses. Jeff holds a J.D. from the University of Washington, School of Law, and a Bachelor of Arts in Political Science from Whitman College.
Leonard Lyons
Vice President of Sales
Len Lyons comes to RefleXion with 22 years of success in radiation oncology including separate executive roles in sales and service. Most recently he was vice president of enterprise solutions for Elekta where he had complete responsibility for developing an elite sales force to win key accounts and large health system opportunities. Lyons also held the positions of vice president of northwest sales, and prior to this, director of sales during his time at Elekta. A cornerstone of Lyons’ success was his multifaceted approach encompassing relationships with strategic partners, building referral patterns, a deep understanding of buyer behavior, and identifying vertical market opportunities. Previous to Elekta, Lyons was vice president of service for IMPAC Medical Systems where he led the integration of two large company acquisitions while exceeding sales and service goals and had responsibility for all revenues through the company’s IPO. Lyons received a Bachelor of Arts in Economics and Computer Studies from the University College Cork, Ireland.
Board of Directors
Our Board comprises an experienced and proven group of individuals dedicated to ensuring all stakeholder needs are met.
Jay Watkins
Board Chairman
Todd Powell
President & CEO, RefleXion
Rana Al-Hallaq, Ph.D.
Pfizer Ventures
Greg Garfield
KCK Group
Matt Hobart
TPG Growth / The Rise Fund
Cem Usakli
PSP Investments
Samuel Mazin, Ph.D.
Founder & CTO, RefleXion
Frederick H. Moll, M.D.
Independent Director
Antoine Papiernik
Sofinnova Partners
Renee Ryan
Independent Director
Alice Schroeder
Independent Director
Scientific advisory board
Dwight Heron, M.D.
Radiation Oncology
Kristin Higgins, M.D.
Radiation Oncology
Robert Timmerman, M.D.
Radiation Oncology
Phuoc Tran, M.D.
Radiation Oncology
James Welsh, M.D.
Radiation Oncology
John Heymach, M.D. Ph.D.
Medical Oncology
J. Luke, M.D.
Medical Oncology
Melinda Telli, M.D.
Medical Oncology
Chaitin Divgi, M.D.
Nuclear Medicine
Martin Pomper, M.D. Ph.D.
Nuclear Medicine