Advances in biological effects of ionizing radiation: Experience from the Inter-University Accelerator Center School-cum-Workshop

I, Dr. Arghya Chattaraj, Scientific Officer in the Radiological Physics and Advisory Division, Medical Group, Bhabha Atomic Research Center (BARC), Mumbai, participated in the School-cum-Workshop on Biological Effect of Ionizing Radiation, organized by the Inter-University Accelerator Center (IUAC), New Delhi, during 24–26 September 2025. IUAC is a premier national facility equipped with advanced accelerator and experimental infrastructure supporting multidisciplinary research. Its major facilities include the 15 UD/16 MV Pelletron tandem accelerator, superconducting linear accelerator, accelerator mass spectrometry facility, Rutherford backscattering spectrometry beamlines, ion irradiation facilities, and specialized bioscience beamlines such as the ASPIRE module. IUAC is also supported by state-of-the-art target and detector laboratories, cryogenics, vacuum and radiofrequency systems, electronics and data support laboratories, high-performance computing facilities (PARAM RUDRA supercomputing facility), and teaching laboratories, making it a unique national hub for accelerator-based research and training. The workshop was designed as an intensive academic program to provide a comprehensive understanding of the biological effects of ionizing radiation, integrating perspectives from radiation physics, radiobiology, medical applications, and accelerator-based research. The scientific program covered a wide range of topics including radiation interaction with biological matter, radioprotection and mitigation strategies, energy loss mechanisms, biomarkers for radiation exposure, FLASH radiotherapy, radiosensitizers, brachytherapy, space radiation health risks, and advanced biological techniques such as CRISPR-Cas9, organoid culture, and electron microscopy. The workshop featured lectures by experts from IUAC, BARC, INMAS-DRDO, ISRO, AIIMS, universities, and international institutions, offering valuable insights on the mentioned topics. I was invited as a resource person and speaker and delivered a lecture titled “Use of Track-Structure Monte Carlo Code in the Field of Radiation Biology,” followed by a hands-on demonstration of Geant4-DNA and TOPAS-nBio packages. My sessions focused on the application of track-structure Monte Carlo simulations for modeling radiation-induced DNA damage, including single-and double-strand breaks, clustered lesions, and their relevance to Relative Biological Effectiveness estimation. Emphasis was placed on the physical and chemical stages of radiation interaction, microscopic energy deposition, selection of physics models, and the challenges in linking simulated quantities with biological endpoints such as cell survival and mutations. The sessions generated active discussions among participants, particularly on the translation of microdosimetric and nanodosimetric quantities into radiobiological models, uncertainty management in simulations, and the role of Monte Carlo tools in complementing experimental radiobiology. The hands-on demonstrations enabled participants to gain practical exposure to modern computational tools increasingly used in medical physics, particle therapy, and radiation protection research. Overall, participation in the School-cum-Workshop on Biological Effect of Ionizing Radiation was a highly enriching professional experience. The exposure strengthened my understanding of emerging trends in radiation biology and reinforced the importance of Monte Carlo-based simulation tools in addressing contemporary problems in medical physics, radioprotection, and space radiation research. The knowledge and interactions gained during this program will be valuable for my ongoing and future responsibilities at BARC. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.