title: Prospective study of direct radiation exposure measurements for family members living with patients with prostate (125)I seed implantation: Evidence of radiation safety.
abstract: To broaden the current understanding of radiation exposure and risk and to provide concrete evidence of radiation safety related to (125)I seed implantation.
  
  
  
  Direct radiation exposure measurements were obtained from dosimeters provided to 25 patients who underwent (125)I seed implantation, along with their family members. The estimated lifetime exposure dose and the precaution time for holding children near the patient's chest were calculated in two study periods.
  
  
  
  During the first and second study period, the mean estimated lifetime exposure doses were, respectively, 7.61 (range: 0.45, 20.21) mSv and 6.84 (range: 0.41, 19.20) mSv for patients, and 0.19 (range: 0.02, 0.54) mSv and 0.25 (range: 0.04, 1.00) mSv for family members. The mean ratios of first and second period measurements were 1.05 (range: 0.44, 3.18) for patients and 1.82 (range: 0.21, 7.04) for family members. The corresponding absolute differences between first and second period measurements were -0.77 (range: -11.40, 7.63) mSv and 0.06 (range: -0.26, 0.79) mSv, respectively. Assuming a dose limit of 1 mSv, the precaution times for holding a child every day of the first and second periods were 250.9 (range: 71.3, 849.4) min and 275.2 (range: 75.0, 883.4) min, respectively. Assuming a dose limit of 0.5 mSv, the corresponding precaution times were 179.0 (range: 35.6, 811.5) min and 178.9 (range: 37.5, 1131.8) min, respectively.
  
  
  
  Our study demonstrated low radiation exposures to family members of patients undergoing (125)I prostate implantation. It was clear that (125)I seed implantation did not pose a threat to the safety of family members.
authors.affiliation: Department of Radiology, Keio University School of Medicine, Tokyo, Japan; Department of Radiology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan. Electronic address: thanada@rad.med.keio.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hanada
authors.affiliation: Department of Radiology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan.
authors.forename: Atsunori
authors.initials: A
authors.lastname: Yorozu
authors.affiliation: Department of Radiology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shinya
authors.affiliation: Department of Radiology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan.
authors.forename: Nobuko
authors.initials: N
authors.lastname: Kuroiwa
authors.affiliation: Department of Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Ohashi
authors.affiliation: Department of Urology, Tokyo Medical Center, National Hospital Organization, Tokyo, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Saito
authors.affiliation: Department of Radiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Shigematsu
mesh_terms: D000368:Aged; D001918:Brachytherapy; D002648:Child; D005190:Family; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000706:statistics & numerical data*; D012111:Residence Characteristics; D012449:Safety; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes
keywords: Brachytherapy; Iodine-125; Prostate cancer; Radiation exposure; Radiation safety