8-Hydroxy-2-Deoxyguanosine as Oxidative DNA Damage Biomarker of Medical Ionizing Radiation: A Scoping Review

Background: Recent studies reported the significant expansion using 8-Hydroxy-2-Deoxyguanosine (8-OHdG) as a biomarker of oxidative Deoxyribonucleic Acid (DNA) damage among human populations exposed to medical ionizing radiation, but a generalized overview about this topic has not been conducted yet. Objective: This scoping review of published literature examined recent trends in utilizing 8-OHdG biomarker to measure oxidative DNA damage induced by medical ionizing radiation and possible factors that may influence the 8-OHdG level.Material and Methods: Literature search was conducted in PubMed, Scopus and ProQuest databases for publications from 1984 to 2/12/2020. Included articles were: cohort studies, case-control studies, and cross–sectional studies, randomized and nonrandomized controlled trials. Excluded articles were: editorials, letters, personal opinions, newspaper articles, study plans, protocols, qualitative studies, case reports and series, in-vivo and vitro studies, animal research studies, reviews and metaanalyses. Results: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we screened 141 articles, and 10 eligible studies met our inclusion criteria. All studies measured 8OHdG as an oxidative DNA damage biomarker. The study results were contradictory concerning the relationship between the radiation dose and 8-OhdG level. 8-OHdG was mostly measured by enzymelinked immunosorbent assay (ELISA) using urine samples. Sample size varied between (n=25230) and included patients who underwent medical radiation procedures or workers exposed to ionizing radiation during their jobs. Conclusion: This scoping review findings showed 8-OHdG can be used as a promising biomarker to detect oxidative damage, resulting from medical ionizing radiation exposure despite external factors that may influence 8-OHdG levels.