Nataliya Kovalchuk

Nataliya Kovalchuk

Clinical Oncologist

Radiation Oncology

Stanford Medicine

Location USA, Stanford

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Dr. Nataliya Kovalchuk is a clinical professor of radiation oncology and medical physicist at Stanford University School of Medicine and Stanford Hospital, and the founder and President of Help Ukraine Group (HUG). Born in Ukraine, she witnessed the Chornobyl disaster as a six-year-old child — an experience that included hospitalization and the loss of a young friend named Marichka to leukemia, a memory that shaped her life’s work. She has spent her career advancing the most technically complex frontiers of radiation oncology, including pioneering the clinical implementation of Volumetric Modulated Arc Therapy Total Body Irradiation (VMAT-TBI) at Stanford and serving as one of the leading investigators in the commissioning and clinical deployment of the world’s first biology-guided radiotherapy (BgRT) system using the RefleXion X1 machine. When Russia launched its full-scale invasion of Ukraine in February 2022, Dr. Kovalchuk founded HUG, an international coalition of oncology practitioners working to sustain and rebuild Ukraine’s cancer care infrastructure. Through partnerships with IAEA, ASTRO, AAPM, ESTRO, and dozens of academic institutions, she has coordinated medical supplies, training programs, software and hardware donations, and international observerships for Ukrainian radiation oncologists and medical physicists.

Current Positions

  • Clinical Professor, Department of Radiation Oncology, Stanford University School of Medicine / Stanford Hospital, August 2024–present
  • Founder and President, Help Ukraine Group (HUG)

Education

  • PhD, Applied Physics — Medical Imaging, University of South Florida, 2004–2008

Professional Experience

  • Research Associate, H. Lee Moffitt Cancer Center and Research Institute, October 2004–May 2008
  • Radiation Oncology Physics Resident, Mayo Clinic, July 2008–July 2010
  • Medical Physicist, Harvard Medical School and Massachusetts General Hospital / Boston Medical Center, August 2010–March 2015
  • Clinical Associate Professor, Department of Radiation Oncology, Stanford University School of Medicine / Stanford Hospital, March 2015–August 2024
  • Clinical Professor, Department of Radiation Oncology, Stanford University School of Medicine / Stanford Hospital, August 2024–present
  • Founder and President, Help Ukraine Group (HUG), February 2022–present

Research Activity

  • VMAT Total Body Irradiation (VMAT-TBI): Pioneered the clinical implementation of VMAT-TBI at Stanford. Developed and published the Stanford VMAT-TBI technique including automated treatment planning scripts, the Spinning Manny indexed overlay system, and gonadal-sparing approaches. Demonstrated superior organ sparing and improved toxicity outcomes compared to conventional 2D TBI. Contributed to Children’s Oncology Group and NRG Oncology working group efforts to incorporate IMRT-TBI into cooperative group clinical trials (International Journal of Radiation Oncology Biology Physics, 2026; Pediatric Blood & Cancer, 2024; Frontiers in Oncology, 2024); 4-year institutional experience with 35+ patients reported.
  • Total Marrow and Lymphoid Irradiation (TMLI): Developed and published automated contouring, treatment planning, and quality assurance for VMAT-TMLI; dosimetric comparison of VMAT-TMLI versus VMAT-TBI using automation scripts (Frontiers in Oncology, 2025).
  • VMAT Craniospinal Irradiation (VMAT-CSI): Developed fully automated workflow for pediatric and adult VMAT-CSI including contouring, planning, and plan quality assurance; published comprehensive automated solution and compared to multi-isocenter linac-based techniques (Frontiers in Oncology, 2024).
  • Biology-guided radiotherapy (BgRT): One of the lead physicists in the commissioning and first clinical implementation of the RefleXion X1, the world’s first biology-guided radiotherapy system, at Stanford. Co-author on beam commissioning, treatment planning system commissioning, IMRT/SBRT treatment planning studies, first-in-human clinical experience (BIOGUIDE-X trial), PET signal evaluation, and dosimetric accuracy studies; published in Journal of Applied Clinical Medical Physics, Technology in Cancer Research & Treatment, Medical Physics, and Advances in Radiation Oncology (2021–2025).
  • Automated treatment planning and quality assurance: Developed automated VMAT planning frameworks for TBI, CSI, TMLI, and head and neck cancer; designed a Six Sigma-based Automated Plan Check (APC) tool for radiation oncology safety and efficiency; published on knowledge-guided and data-driven treatment planning approaches; contributed to machine learning and deep learning models for dose prediction and DVH prediction (Medical Physics, Journal of Applied Clinical Medical Physics, Physics in Medicine & Biology).
  • PET/CT in radiation therapy planning: Research on deformable registration of pre- and post-operative PET/CT for head and neck cancer radiation therapy planning; published in Radiographics, American Journal of Roentgenology, and International Journal of Radiation Oncology Biology Physics (2012).
  • Head and neck radiotherapy: Serial CT-based assessment of parotid gland changes during IMRT; brachial plexus dosimetry and tumor volume correlation; cochlear dose and hearing loss in IMRT; volumetric tumor burden and outcome during head and neck IMRT.
  • Brachytherapy: Research on prostate high-dose-rate brachytherapy dosimetry and iris melanoma brachytherapy using modified COMS plaque (published in Brachytherapy, 2009 and 2011).
  • Radiation oncology in Ukraine during the war: Founder and primary investigator of the HUG research program documenting the impact of war on radiotherapy services in Ukraine; published in Advances in Radiation Oncology (2022), International Journal of Radiation Oncology Biology Physics (2023–2025), BMJ Oncology (2026), Frontiers in Oncology (2026), and JCO Global Oncology (2026); led documentation of 50+ international observerships for Ukrainian radiation oncologists and medical physicists across 14 institutions in the US and abroad; co-led the AAPM/HUG/UAMP hybrid training program to transition Ukrainian medical physicists from Co-60 to IMRT (JCO Global Oncology, 2026).

Honors and Awards

  • Fellow of the American Association of Physicists in Medicine (FAAPM)
  • Stanford Global Studies funding secured to sponsor visiting Ukrainian medical scholars at Stanford
  • Stanford Healthcare donation of over $415,000 in medical supplies to Ukraine, spearheaded in part by Dr. Kovalchuk
    Secured 24 international training positions for Ukrainian oncology practitioners through HUG in partnership with GMKA and Union for International Cancer Control

Memberships / Affiliations

  • Fellow, American Association of Physicists in Medicine (FAAPM)
  • Help Ukraine Group (HUG) — Founder and President
  • Ukrainian Alliance for Medical Exchange and Development (UA-MED) — founding member
  • American Association of Physicists in Medicine (AAPM) — International Council collaborator
  • American Society for Radiation Oncology (ASTRO) — collaborator
  • International Atomic Energy Agency (IAEA) — collaborator
  • European Society for Radiotherapy and Oncology (ESTRO) — collaborator
  • Ukrainian Association of Medical Physicists (UAMP) — partner organization
    Ukrainian Society of Medical Oncology — partner organization

Areas of Specialization

  • Radiation oncology medical physics
  • Volumetric modulated arc therapy total body irradiation (VMAT-TBI)
  • Total marrow and lymphoid irradiation (TMLI)
  • VMAT craniospinal irradiation (VMAT-CSI)
  • Biology-guided radiotherapy (BgRT) — RefleXion X1 commissioning and implementation
  • Automated treatment planning and quality assurance
  • PET/CT in radiation therapy planning
  • Head and neck intensity-modulated radiation therapy
  • Brachytherapy (prostate, ocular)
  • Global radiotherapy access and capacity building in LMICs
  • Radiation oncology during humanitarian crises and armed conflict
  • Oncology workforce development for Ukraine

Publications

Dr. Kovalchuk has authored and co-authored more than 157 publications in International Journal of Radiation Oncology Biology Physics, Medical Physics, Journal of Applied Clinical Medical Physics, Frontiers in Oncology, BMJ Oncology, BMJ Open, JCO Global Oncology, Advances in Radiation Oncology, Technology in Cancer Research & Treatment, Practical Radiation Oncology, Applied Radiation Oncology, Pediatric Blood & Cancer, Anatomical Sciences Education, Physics in Medicine & Biology, Radiographics, Brachytherapy, Seminars in Radiation Oncology, and others.

Select Recent Publications:

Ashmeg S, Aldosary G, El-Amin YY, Kovalchuk N, et al. “Can Radiation Therapy Services Survive in Conflict-Affected Regions?” International Journal of Radiation Oncology Biology Physics, May 2026.

Lozko Y, Beznosenko A, Suchowerska N, Kovalchuk N, et al. “Advancing radiation oncology care in Ukraine during the war: impact of international observerships on professional development and clinical practice.” Frontiers in Oncology, March 2026.

Zelinskyi R, Brovchuk S, Ainsworth V, Kovalchuk N, et al. “Deployment of a Tailored and Hybrid Educational Strategy for Wartime Capacity Building: AAPM/HUG/UAMP Training Program to Transition Ukraine From Co-60 to IMRT.” JCO Global Oncology, February 2026.

Karavska A, Kizub D, Kovalchuk N, Melnitchouk N, et al. “Cancer care in wartime Ukraine: disruption, resilience and recovery.” BMJ Oncology, February 2026.

Kovalchuk N, Simiele E, LaRiviere M, Milgrom S, et al. “Incorporating Intensity Modulated Total Body Irradiation (IMRT-TBI) into Future Cooperative Group Clinical Trials.” International Journal of Radiation Oncology Biology Physics, February 2026.

Pidvalna U, Davis D, Kovalchuk N, Plyatsko R, et al. “The origins of neuroimaging and Johann Puluj: Early X-rays and the foundations of radiographic neuroanatomy.” Anatomical Sciences Education, March 2026.

Skinner L, Simiele E, Yang Z, Kovalchuk N, et al. “The Spinning Manny Indexed Overlay System for VMAT total body irradiation.” Journal of Applied Clinical Medical Physics, January 2026.

Kovalchuk N, Zinchuk A, Beznosenko A, Melnitchouk N, et al. “Impact of international observerships on Ukrainian healthcare professionals during the war: a cross-sectional survey study.” BMJ Open, January 2026.

Simiele E, Hui C, Romero I, Kovalchuk N, et al. “Automated contouring, treatment planning, and quality assurance for total marrow lymphoid irradiation.” Frontiers in Oncology, November 2025.

Watkins WT, Yang R, Han C, Carlson DJ, Kovalchuk N, et al. “Commissioning of the RefleXion X1 Linear Accelerator and Development of a Consensus Reference Beam Model.” Medical Physics, November 2025.

Hui C, Simiele E, Lozko Y, Hiniker SM, Kovalchuk N, et al. “Volumetric modulated arc therapy total body irradiation improves toxicity outcomes compared to 2D total body irradiation.” Frontiers in Oncology, September 2024.

Simiele E, Romero I, Wang JY, Kovalchuk N, et al. “Automated contouring, treatment planning, and quality assurance for VMAT craniospinal irradiation (VMAT-CSI).” Frontiers in Oncology, April 2024.

Surucu M, Ashraf MR, Romero I, Han B, Kovalchuk N, et al. “Commissioning of a novel PET-Linac for biology-guided radiotherapy (BgRT).” Medical Physics, May 2024.

Kovalchuk N, Zelinskyi R, Stadnyk L, Beznosenko A, et al. “Radiotherapy Under the Falling Bombs: Lessons from Ukraine.” International Journal of Radiation Oncology Biology Physics, October 2024.

Shi M, Simiele E, Han B, Kovalchuk N, et al. “First-year experience of SBRT/IMRT treatment using a novel biology-guided radiotherapy machine.” Advances in Radiation Oncology, June 2023.

Han B, Kovalchuk N, Gensheimer M, Surucu M, et al. “Stanford Experience With Commissioning, Quality Assurance and IMRT/SBRT Treatment of the First Biology-Guided Radiation Therapy Machine.” Applied Radiation Oncology, June 2023.

Kovalchuk N, Zelinskyi R, Hanych A, Suchowerska N, et al. “Radiotherapy under the falling bombs: a tale of two Ukrainian cancer centers.” Advances in Radiation Oncology, July 2022.

Kovalchuk N. “Help Ukraine.” Advances in Radiation Oncology, April 2022. (Full-text, including artwork “Help Ukraine” by Nataliya Kovalchuk.)

Kovalchuk N, Beznosenko A, Kowalchuk R, Kacharian A, et al. “While Ukrainian Soldiers Are Fearlessly Defending Their Country, Ukrainian Oncologists Are Bravely Battling Cancer.” Advances in Radiation Oncology, April 2022.

Han B, Capaldi D, Kovalchuk N, Surucu M, et al. “Beam commissioning of the first clinical biology-guided radiotherapy system.” Journal of Applied Clinical Medical Physics, April 2022.

Pham D, Simiele E, Breitkreutz D, Kovalchuk N, et al. “IMRT and SBRT Treatment Planning Study for the First Clinical Biology-Guided Radiotherapy System.” Technology in Cancer Research & Treatment, May 2022.

Kovalchuk N, Simiele E, Skinner L, Hiniker SM, et al. “The Stanford VMAT TBI Technique.” Practical Radiation Oncology, February 2022.

Simiele E, Skinner L, Yang Y, Kovalchuk N, et al. “A step towards making VMAT TBI more prevalent: automating the treatment planning process.” Practical Radiation Oncology, March 2021.

Blomain E, Kovalchuk N, Skinner L, Hiniker SM, et al. “A preliminary report of gonadal-sparing TBI using a VMAT technique.” Practical Radiation Oncology, August 2020.

Liu S, Bush K, Bertini J, Kovalchuk N, Xing L, et al. “Optimizing efficiency and safety in external beam radiotherapy using automated plan check (APC) tool and six sigma methodology.” Journal of Applied Clinical Medical Physics, August 2019.

Ma M, Kovalchuk N, Buyyounouski MK, Yang Y, et al. “Dosimetric features-driven machine learning model for DVH prediction in VMAT treatment planning.” Medical Physics, January 2019.

Kovalchuk N, Furutani K, Macdonald OK, Pisansky TM. “Dosimetric effect of interfractional needle displacement in prostate high-dose-rate brachytherapy.” Brachytherapy, June 2011.

All information is sourced from publicly available materials.