title: Biomarkers and surrogate endpoints for normal-tissue effects of radiation therapy: the importance of dose-volume effects.
abstract: Biomarkers are of interest for predicting or monitoring normal tissue toxicity of radiation therapy. Advances in molecular radiobiology provide novel leads in the search for normal tissue biomarkers with sufficient sensitivity and specificity to become clinically useful. This article reviews examples of studies of biomarkers as predictive markers, as response markers, or as surrogate endpoints for radiation side effects. Single nucleotide polymorphisms are briefly discussed in the context of candidate gene and genomewide association studies. The importance of adjusting for radiation dose distribution in normal tissue biomarker studies is underlined. Finally, research priorities in this field are identified and discussed.
authors.affiliation: Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA. bentzen@humonc.wisc.edu
authors.forename: Søren M
authors.initials: SM
authors.lastname: Bentzen
authors.forename: Matthew
authors.initials: M
authors.lastname: Parliament
authors.forename: Joseph O
authors.initials: JO
authors.lastname: Deasy
authors.forename: Adam
authors.initials: A
authors.lastname: Dicker
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Curran
authors.forename: Jacqueline P
authors.initials: JP
authors.lastname: Williams
authors.forename: Barry S
authors.initials: BS
authors.lastname: Rosenstein
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D016207:Cytokines / Q000032:analysis; D004307:Dose-Response Relationship, Radiation; D005819:Genetic Markers; D055106:Genome-Wide Association Study / Q000379:methods; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011832:Radiation Injuries / Q000175:diagnosis*; D011836:Radiation Tolerance / Q000235:genetics / Q000502:physiology*; D011878:Radiotherapy / Q000009:adverse effects*; D009626:Terminology as Topic; D053773:Transforming Growth Factor beta1 / Q000032:analysis
chemical_list: D015415:Biomarkers; D016207:Cytokines; D005819:Genetic Markers; D053773:Transforming Growth Factor beta1