Our Leadership Team

Kal Fishman – President & Chief Executive Officer

Mr. Fishman is a serial entrepreneur in the fields of radiation oncology and radiology. Mr. Fishman is the inventor of the robotically-assisted Morpheus™ beam sculpting image-guided radiotherapy system, which was taken from concept to FDA submission and clearance in approximately eighteen months and is Empyrean’s first commercial product. Before founding and launching Empyrean Medical Systems, Mr. Fishman was the co-founder and served as the Chief Technology Officer and Chief Operations Officer of Sensus Healthcare, Inc., a publicly traded company (Nasdaq®: SRTS) specializing in superficial, brachytherapy, and intraoperative oncological radiation therapy systems from 2010 to 2019. In addition, he held executive positions at other medical device companies, including GE Healthcare, Siemens Medical Systems, CTI, Elscint, Positron Medical Systems, and Rcadia Medical Imaging. He is a GE-certified Six-Sigma DFSS/DMAIC Black Belt. Before that, Mr. Fishman was a senior research and development engineer in the Israeli Air Force R&D Core at the Airborne Intelligence and Cryptography Division. Mr. Fishman holds over ten patents in radiation oncology, radiology, and bioinformatics. He also serves as the Chairman of the Board of Directors.

Liran Marelli – Chief Financial Officer. M.B.A, CPA

With over 20 years of experience in financial management, Mr. Marelli is an experienced finance executive with demonstrated skills and knowledge that are instrumental in an organization’s strategic leadership. Highly skilled in Strategic Planning, Finance Operations, Planning and Budgeting, Accounting, and Corporate Governance. He began his career in Public Accounting at Ernst & Young. He continued a path of leading finance roles in several companies, from start-ups to multinational corporations, in the High-Tech, Fin-Tech, and pharmaceutical industries. He recently served as a CFO at a leading global pharmaceutical corporation, bringing his knowledge and experience to the management team, and leading the organization to significant growth, while improving costs and streamlining supply-chain operations. Mr. Marelli obtained accounting and MBA degrees from Florida Atlantic University and is a Certified Public Accountant in Florida and Israel.

Pavlina Frolik
Pavlina Frolik – Vice President of Sales & Marketing
Mrs. Frolik leads the company’s commercial strategy, brand development, and go-to-market execution, translating vision into measurable market impact.

She is an experienced marketing and sales leader with a proven track record of building and scaling global brands, launching products, and turning strategy into revenue-generating execution. She combines strategic thinking with hands-on execution, driven by a genuine belief that meaningful innovation can improve lives. For good.

Her work sits at the intersection of strategy and execution—aligning teams, products, and markets to drive sustained commercial momentum.

Mrs. Frolik brings broad experience across Rx, OTC, and medical devices, with leadership roles spanning Europe and the United States.

Johnathan Vainer – Chief Technology Officer

Before becoming Empyrean’s Chief Technology Officer, Mr. Vainer served as Chief Technology Officer at Sensus Healthcare (NASDAQ®: SRTS). Mr. Vainer brings extensive medical device and advanced technology research and development experience from his tenure at Sensus Healthcare and the organizations with which he held vital roles. He oversaw the development of smart aesthetic laser systems, superficial radiation therapy systems, cloud operating systems, electronic medical records (EMR) systems, and advanced treatment planning systems (TPS). In addition, Mr. Vainer has extensive experience in medical device regulatory submission and clearance and R&D programs management. Prior to that, Mr. Vainer was a software developer at Connecteam and a senior systems engineer at the Israeli Navy. Yonatan attended The School of Computer Science at Tel Aviv University, Israel.

Dirk Bartkoski, M.Sc., Ph.D. – Chief Scientific Officer

Recently served as a computational scientist in the Department of Radiation Physics at the MD Anderson Cancer Center in Houston, Texas, Dr. Bartkoski is a co-inventor of the MOVHEET technology. He received his master’s in 2005 and doctorate in 2013 from the University of Tennessee, both in the field of particle accelerators, with research conducted at the Spallation Neutron Source at Oak Ridge National Laboratory. Transitioning to Medical Physics, he obtained a certificate in Medical Physics from the University of Texas, Graduate School of Biomedical Sciences at Houston. He completed a postdoctoral fellowship at MD Anderson in 2016. Dr. Bartkoski is specialized in developing multiple cancer treatment delivery technologies based on converging radiation beams. As Empyrean’s Chief Scientific Officer, Dr. Bartkoski oversees all the translational science work, particle ballistics simulation, next generation scientific and technological research and development, and the implementation of contemporary and future scientific breakthroughs in Empyrean’s product lines.

Jacob Scott, MD, DPhil – Medical Director, Chief Physician Scientist & Chairman of the Scientific Advisory Board

Dr. Scott is a board-certified radiation oncologist and physician-scientist at Cleveland Clinic. He serves as Associate Cancer Center Director for Data Science at Case Western Reserve University. He runs an NIH-funded laboratory studying evolutionary therapy – a field he has been pioneering to harness evolution to treat cancer and complex infections. As a world leader in evolutionary biology and cancer treatment, Dr. Scott brings years of experience and thought leadership to our team. He also holds the role of Adjunct Assistant Professor in the Department of Physics at Case Western Reserve University. Dr. Scott also specializes in the care of patients with Sarcoma. He is a theoretical biologist who thinks about and studies the fundamental evolutionary mechanisms driving therapeutic resistance in cancer and pathogens. While in the lab, he dedicates himself to finding new therapeutic paths to defeat cancer and spends his time working with and mentoring his lab researchers and students.

Dror Alezra, M.Sc, Ph.D. – Chief Physicist

Recently served as Chief Physicist and Chairman at Sheba Medical Center’s radiotherapy department at Tel Hashomer, Israel, Dr. Alezra is the original inventor of the MOVHEET technology. As Chief Physicist at Empyrean, Dr. Alezra oversees all the translational physics research and development, product ideation, medical physics, treatment planning algorithms development, neuro-network training, and core systems physics of Empyrean’s radiation therapy technologies and product lines. Dr. Alezra is an accomplished researcher, a serial inventor, and a well-published scientist with over thirty-five international publications. Dr. Alezra received his BSc., M.Sc., and Ph.D. in Nuclear Physics from Ben Gurion University in Israel. Between 1999 and early 2020, Dr. Alezra served as the Chairman of the Israeli Association of Medical Physics. Dr. Alezra also served on many Scientific Advisory Boards of the industry’s leading companies and is a scientific consultant to several innovative startup companies in Israel. In addition, Dr. Alezra serves as an Adjunct Professor of Radiation Physics and Radiation Oncology at the University of Texas, MD Anderson Cancer Center, and as an Adjunct Senior Lecturer at the Ben-Gurion University of the Negev in Israel.