Deoxyribonucleic acid damage-associated biomarkers of ionising radiation: current status and future relevance for radiology and radiotherapy

Diagnostic and therapeutic radiation technology has developed dramatically in recent years, and its use has increased significantly, bringing clinical benefit. The use of diagnostic radiology has become widespread in modern society, particularly in paediatrics where the clinical benefit needs to be balanced with the risk of leukaemia and brain cancer increasing after exposure to low doses of radiation. With improving long-term survival rates of radiotherapy patients and the ever-increasing use of diagnostic and interventional radiology procedures, concern has risen over the long-term risks and side effects from such treatments. Biomarker development in radiology and radiotherapy has progressed significantly in recent years to investigate the effects of such use and optimise treatment. Recent biomarker development has focused on improving the limitations of established techniques by the use of automation, increasing sensitivity and developing novel biomarkers capable of quicker results. The effect of low-dose exposure (0–100 mGy) used in radiology, which is increasingly linked to cancer incidences, is being investigated, as some recent research challenges the linear-no-threshold model. Radiotherapy biomarkers are focused on identifying radiosensitive patients, determining the treatment-associated risk and allowing for a tailored and more successful treatment of cancer patients. For biomarkers in any of these areas to be successfully developed, stringent criteria must be applied in techniques and analysis of data to reduce variation among reports and allow data sets to be accurately compared. Newly developed biomarkers can then be used in combination with the established techniques to better understand and quantify the individual biological response to exposures associated with radiology tests and to personalise treatment plans for patients.Research into the identification of biomarkers of radiation exposure is an emerging and developing area with multiple possible benefits for patients, doctors and the general public. A radiation biomarker is a biological entity that changes after exposure to radiation, allowing exposed individuals to be identified and, with some biomarkers, a dose to be estimated. There are different types of biomarkers, including chromosome aberrations, protein expression or gene expression. Some can measure accurately the dose received, while others can only indicate if a dose was received. Biomarkers can help clinicians manage treatment for a patient exposed accidentally to the wrong radiation dose or on purpose through radiotherapy. They may be able to predict the treatment response of a tumour and estimate the risk of acute or late effects in normal tissues. Biomarkers can also identify the dose received by the patient in a full or partial body exposure. Such information can help inform the necessary medical treatment plan for the patient, and it may also identify patients with a high likelihood of developing cancer in the future so that regular monitoring can be set up.