title: Cancer and non-cancer brain and eye effects of chronic low-dose ionizing radiation exposure.
abstract: BACKGROUND
  According to a fundamental law of radiobiology ("Law of Bergonié and Tribondeau", 1906), the brain is a paradigm of a highly differentiated organ with low mitotic activity, and is thus radio-resistant. This assumption has been challenged by recent evidence discussed in the present review.
  
  
  RESULTS
  Ionizing radiation is an established environmental cause of brain cancer. Although direct evidence is lacking in contemporary fluoroscopy due to obvious sample size limitation, limited follow-up time and lack of focused research, anecdotal reports of clusters have appeared in the literature, raising the suspicion that brain cancer may be a professional disease of interventional cardiologists. In addition, although terminally differentiated neurons have reduced or mild proliferative capacity, and are therefore not regarded as critical radiation targets, adult neurogenesis occurs in the dentate gyrus of the hippocampus and the olfactory bulb, and is important for mood, learning/memory and normal olfactory function, whose impairment is a recognized early biomarker of neurodegenerative diseases. The head doses involved in radiotherapy are high, usually above 2 Sv, whereas the low-dose range of professional exposure typically involves lifetime cumulative whole-body exposure in the low-dose range of < 200 mSv, but with head exposure which may (in absence of protection) arrive at a head equivalent dose of 1 to 3 Sv after a professional lifetime (corresponding to a brain equivalent dose around 500 mSv).
  
  
  CONCLUSIONS
  At this point, a systematic assessment of brain (cancer and non-cancer) effects of chronic low-dose radiation exposure in interventional cardiologists and staff is needed.
authors.affiliation: Institute Clinical Physiology of the National Research Council CNR, 56124, Pisa, Italy. picano@ifc.cnr.it
authors.forename: Eugenio
authors.initials: E
authors.lastname: Picano
authors.forename: Eliseo
authors.initials: E
authors.lastname: Vano
authors.forename: Luciano
authors.initials: L
authors.lastname: Domenici
authors.forename: Matteo
authors.initials: M
authors.lastname: Bottai
authors.forename: Isabelle
authors.initials: I
authors.lastname: Thierry-Chef
mesh_terms: D001921:Brain / Q000528:radiation effects*; D001932:Brain Neoplasms / Q000209:etiology*; D002309:Cardiology; D003071:Cognition / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005123:Eye / Q000528:radiation effects*; D005134:Eye Neoplasms / Q000209:etiology*; D006282:Health Personnel; D006801:Humans; D009381:Neoplasms, Radiation-Induced / Q000209:etiology*; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D011832:Radiation Injuries / Q000209:etiology*