title: Radiation doses to cohabitants of patients undergoing radioiodine ablation for thyroid cancer: poor compliance with radiation protection guidelines but low radiation exposure.
abstract: BACKGROUND
  The drive to reduce hospital stay after radioiodine remnant ablation in patients with thyroid cancer may increase the risk of radiation exposure to family members. The aim of this study was to evaluate the key determinants of dose exposure to familial members, with particular reference to the degree of adherence to current radiation safety guidelines.
  
  
  METHODS
  All participants prospectively received our standard departmental oral and written safety instructions, with a mandatory 3-day restriction period. The postmicturition radiation levels of treated patients were measured (at 1-m distance) at the time of discharge using a portable radiometer. The radiation exposure of cohabitants was assessed with an optically stimulated luminescence-based personal dosimeter during the 3 days after hospital discharge. A questionnaire was used to assess the adherence of relatives/cohabitants to radiation safety guidelines.
  
  
  RESULTS
  A total of 38 patients with thyroid cancer and 48 household members were included. At 48 h post therapy, the patient's median emission at 1-m distance was 13.4 μSv/h. The mean cumulative cohabitant exposure was 102 μSv (<50-1000). A positive correlation between cohabitant radiation exposure and the radiation level of the patient was observed (P=0.016). This correlation was absent when the recommended guidelines were followed (P=0.56). Only 17 household members (35.4%) strictly followed the recommended guidelines, but dose exposures exceeded 0.3 mSv in only four cases, in which a mean of between 5.8 and 9.5 h were spent in close proximity to the patient in the first 3 days, including sleeping with treated patients in half of the cases.
  
  
  CONCLUSIONS
  Despite poor compliance with safety guidelines, a short-stay protocol respects current legislation, and is applicable to most patients treated with 3.7 GBq for radioiodine remnant ablation.
authors.affiliation: Department of Nuclear Medicine, Timone Hospital, Marseille, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Gabriel
authors.forename: Bardia
authors.initials: B
authors.lastname: Farman-Ara
authors.forename: Marc
authors.initials: M
authors.lastname: Bourrelly
authors.forename: Olivier
authors.initials: O
authors.lastname: Carpentier
authors.forename: Frederic
authors.initials: F
authors.lastname: Sebag
authors.forename: Fausto F
authors.initials: FF
authors.lastname: Palazzo
authors.forename: Catherine
authors.initials: C
authors.lastname: De Micco
authors.forename: Julien
authors.initials: J
authors.lastname: Mancini
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Henry
authors.forename: Olivier
authors.initials: O
authors.lastname: Mundler
authors.forename: David
authors.initials: D
authors.lastname: Taïeb
mesh_terms: D055011:Ablation Techniques / Q000009:adverse effects*; D000328:Adult; D000368:Aged; D004781:Environmental Exposure / Q000009:adverse effects / Q000706:statistics & numerical data*; D005190:Family; D005260:Female; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006761:Hospitals; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge; D017410:Practice Guidelines as Topic; D011829:Radiation Dosage; D011835:Radiation Protection / Q000592:standards*; D012449:Safety; D013964:Thyroid Neoplasms / Q000601:surgery*; D013997:Time Factors; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes