title: Outpatient radioiodine therapy for thyroid cancer: a safe nuclear medicine procedure.
abstract: OBJECTIVE
  To evaluate the dosimetric effect of outpatient radioiodine therapy for thyroid cancer in members of a patient's family and their living environment, when using iodine-131 doses reaching 7.4 GBq. The following parameters were thus defined: (a) whole-body radiation doses to caregivers, (b) the production of contaminated solid waste, and (c) radiation potential and surface contamination within patients' living quarters.
  
  
  METHODS
  In total, 100 patients were treated on an outpatient basis, taking into consideration their acceptable living conditions, interests, and willingness to comply with medical and radiation safety guidelines. Both the caregivers and the radiation dose potentiality inside patients' residences were monitored by using thermoluminescent dosimeters. Surface contamination and contaminated solid wastes were identified and measured with a Geiger-Müller detector.
  
  
  RESULTS
  A total of 90 monitored individuals received a mean dose of 0.27 (±0.28) mSv, and the maximum dose registered was 1.6 mSv. The mean value for the potential dose within all living quarters was 0.31 (±0.34) mSv, and the mean value per monitored surface was 5.58 Bq/cm(2) for all the 1659 points measured. The overall production of contaminated solid wastes was at a low level, being about 3 times less than the exemption level indicated by the International Atomic Energy Agency.
  
  
  CONCLUSIONS
  This study indicates that the treatment of thyroid cancer by applying radioiodine activities up to 7.4 GBq, on an outpatient basis, is a safe procedure, especially when supervised by qualified professionals. This alternative therapy should be a topic for careful discussion considering the high potential for reducing costs in healthcare and improving patient acceptance.
authors.affiliation: Department of Radiology, School of Medicine, University of São Paulo, São Paulo, Brazil. willegaignon@hotmail.com
authors.forename: José
authors.initials: J
authors.lastname: Willegaignon
authors.forename: Marcelo
authors.initials: M
authors.lastname: Sapienza
authors.forename: Carla
authors.initials: C
authors.lastname: Ono
authors.forename: Tomoco
authors.initials: T
authors.lastname: Watanabe
authors.forename: Maria Inês
authors.initials: MI
authors.lastname: Guimarães
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gutterres
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Marechal
authors.forename: Carlos
authors.initials: C
authors.lastname: Buchpiguel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000379:methods*; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009683:Nuclear Medicine / Q000379:methods*; D011879:Radiotherapy Dosage; D012449:Safety; D013964:Thyroid Neoplasms / Q000532:radiotherapy*; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes