ISLAMABAD: A research project carried out by the International Atomic Energy Agency (IAEA) has strengthened global understanding of how exposure to ionising radiation affects human health.

According to the IAEA’s latest bulletin, the work focused on clinical applications of biodosimetry — the use of biological responses to estimate the amount of ionising radiation a patient receives. Over several years, it generated new data expanding the potential of dosimetric biomarkers, biological indicators that reflect radiation exposure.

“Within everyday clinical practice, the move towards personalised medicine requires assays to accurately assess radiation exposure at the individual level,” said Oleg Belyakov, an IAEA radiobiologist and the project’s technical officer. “Beyond ensuring patient safety, these specialised tests are critical for predicting how normal tissues respond to clinical procedures involving ionising radiation.”

He added, “While previously validated biological indicators offer a promising foundation, there are a number of knowledge gaps and methodological limitations which need to be addressed before these markers can serve as a reliable tool to inform routine clinical decision-making.”

New biodosimetry data may support safer use of medical radiation

To address this challenge, the IAEA launched a coordinated research project (MEDBIODOSE) in 2017 to examine the role of biodosimetric markers and methods within radiation oncology, nuclear medicine and diagnostic and interventional radiology.

Thirty-one institutions joined the project, and each team collected and analysed patients’ biodosimetric data — biological measurements and observations used to estimate a person’s radiation exposure. This included cytogenetic data (chromosomal aberrations) and molecular data (protein markers associated with damaged DNA and any changes in gene expression).

With over 100 publications resulting from their analyses, researchers identified several new biomarkers that signalled a biological response to radiation. These indicators were validated in terms of their relevance and reliability and used to generate calibration curves for estimating the absorbed dose.

By using cells from multiple donors, the project’s participants could examine variations in radiation response — enabling the identification of radiosensitive individuals who may require specific radiation procedures and protection measures.

Laboratory experiments simulating uneven or partial radiation exposure at high doses provided important baseline data to improve existing methods for checking radiation exposure in clinical environments. The study’s scientists also developed new devices for the rapid — and in some cases automated — analysis of radiation biomarkers.

Among other outcomes, resear­chers demonstrated that standard biodosimetric methods are capable of detecting any chromosomal breaks in a patient’s lymphocytes — a type of specialised white blood cell — after a single computed tomography (CT) scan.

Since low-dose CT scans for screening lung cancer do not appear to damage human DNA, this finding can help address concerns around increased risks of radiation-induced cancer.

Published in Dawn, January 11th, 2026