Cytogenetics Group

About the lab

Members of UKHSA's Cytogenetics Group are internationally recognised as leading experts in research to identify, develop and validate biomarkers of radiation exposure. These can be used to provide an indication of radiation dose received by individuals in routine cases of suspected overexposure as well as for triage of large numbers of suspected exposed individuals in a radiation emergency. This work feeds directly into our Chromosomal Dosimetry Service.

Wider research interests: CDS staff have expertise in general radiation protection, including whole body irradiation syndromes, cancer pathology and non-cancer effects including radiation cataractogenesis. Contact us to discuss your advice, training or collaborative research needs.

Featured projects (1)

Featured research (188)

Purpose: Cataract (opacification of the ocular lens) is a typical tissue reaction (deterministic effect) following ionizing radiation exposure, for which prevention dose limits have been recommended in the radiation protection system. Manifestations of radiation cataracts can vary among individuals, but such potential individual responses remain uncharacterized. Here we review relevant literature and discuss implications for radiation protection. This review assesses evidence for significant modification of radiation-induced cataractogenesis by age at exposure, sex and genetic factors based on current scientific literature. Conclusions: In addition to obvious physical factors (e.g. dose, dose rate, radiation quality, irradiation volume), potential factors modifying individual responses for radiation cataracts include sex, age and genetics, with comorbidity and coexposures also having important roles. There are indications and preliminary data identifying such potential modifiers of radiation cataract incidence or risk, although no firm conclusions can yet be drawn. Further studies and a consensus on the evidence are needed to gain deeper insights into factors determining individual responses regarding radiation cataracts and the implications for radiation protection.
Recent epidemiological and experimental animal data, as well as reanalyses of data previously accumulated, indicate that the lens of the eye is more radiosensitive than was previously thought. This has resulted in a reduction of the occupational lens dose limit within the European Union countries, Japan and elsewhere. This Commentary introduces the work done by the LDLensRad Consortium contained within this Focus Issue, towards advancement of understanding of the mechanisms of low dose radiation cataract.
Introduction Radium-223 dichloride ([²²³Ra]RaCl2), a radiopharmaceutical that delivers α-particles to regions of bone metastatic disease, has been proven to improve overall survival of men with metastatic castration resistant prostate cancer (mCRPC). mCRPC patients enrolled on the ADRRAD clinical trial are treated with a mixed field exposure comprising radium-223 (²²³Ra) and intensity modulated radiotherapy (IMRT). While absorbed dose estimation is an important step in the characterisation of wider systemic radiation risks in nuclear medicine, uncertainties remain for novel radiopharmaceuticals such as ²²³Ra. Methods 24-Colour karyotyping was used to quantify the spectrum of chromosome aberrations in peripheral blood lymphocytes of ADRRAD patients at incremental times during their treatment. Dicentric equivalent frequencies were used in standard models for estimation of absorbed blood dose. To account for the mixed field nature of the treatment, existing models were used to determine the ratio of the component radiation types. Additionally, a new approach (M-FISHLET), based on the ratio of cells containing damage consistent with high-LET exposure (complex chromosomal exchanges) and low-LET exposure (simple exchanges), was used as a pseudo ratio for ²²³Ra:IMRT dose. Results Total IMRT estimated doses delivered to the blood after completion of mixed radiotherapy (after 37 IMRT fractions and two [²²³Ra]RaCl2 injections) were in the range of 1.167 ± 0.092 and 2.148 ± 0.096 Gy (dose range across all models applied). By the last treatment cycle analysed in this study (four [²²³Ra]RaCl2 injections), the total absorbed ²²³Ra dose to the blood was estimated to be between 0.024 ± 0.027 and 0.665 ± 0.080 Gy, depending on the model used. Differences between the models were observed, with the observed dose variance coming from inter-model as opposed to inter-patient differences. The M-FISHLET model potentially overestimates the ²²³Ra absorbed blood dose by accounting for further PBL exposure in the vicinity of metastatic sites. Conclusions The models presented provide initial estimations of cumulative dose received during incremental IMRT fractions and [²²³Ra]RaCl2 injections, which will enable improved understanding of the doses received by individual patients. While the M-FISHLET method builds on a well-established technique for external exposures, further consideration is needed to evaluate this method and its use in assessing non-targeted exposure by ²²³Ra after its localization at bone metastatic sites.
Purpose Based on the experience of biodosimetry laboratories during the COVID-19 pandemic, the purpose of this paper is to describe the challenges of providing biodosimetry service in the event of a major radiation incident during a pandemic. This includes describing some of the preparations and planning made by biodosimetry laboratories and special challenges in maintaining a state of readiness while adhering to safety protocols and balancing the need to assist with the COVID-19 response where possible. Experiences of several biodosimetry laboratories will be described and lessons learned will be outlined that could be applied to any large population-scale emergencies. Conclusions There are many challenges that arise when maintaining capacity and capabilities for biodosimetry when faced with a global pandemic such as COVID-19. The key is to be prepared for anything within reason. This includes, but is not limited to, maintaining flexibility, shifting and reorganizing deployment of staff between pandemic response and biodosimetry needs, strengthening networks to be able to provide assistance to other laboratories, managing staff in the face of possible infections and preparing protocols for the handling of potentially infected biological samples according to regulatory requirements. By implementing these recommendations, international biodosimetry networks can be prepared to address large-scale radiological incidents within the context of a pandemic and ensure the safety of biodosimetry personnel as well as victims in such dual emergencies.

Members (4)

Jayne Moquet
  • Public Health England
Stephen G R Barnard
  • UK Health Security Agency
Michele Ellender
  • Public Health England
Mingzhu Sun
  • Public Health England

Alumni (6)

Melvin Lee Kiang Chua
  • National Cancer Centre Singapore
Kai Rothkamm
  • University Medical Center Hamburg - Eppendorf
David Lloyd
  • Public Health England
Manuel Higueras
  • Universidad de La Rioja (Spain)