Prospective study of direct radiation exposure measurements for family members living with patients with prostate 125I seed implantation: Evidence of radiation safety

Takashi Hanada, Atsunori Yorozu, Yukiko Shinya, Nobuko Kuroiwa, Toshio Ohashi, Shiro Saito, Naoyuki Shigematsu

Research output: Contribution to journalArticle

3 Citations (Scopus)


Purpose: To broaden the current understanding of radiation exposure and risk and to provide concrete evidence of radiation safety related to 125I seed implantation. Methods and Materials: Direct radiation exposure measurements were obtained from dosimeters provided to 25 patients who underwent 125I 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. Results: 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. Conclusions: Our study demonstrated low radiation exposures to family members of patients undergoing 125I prostate implantation. It was clear that 125I seed implantation did not pose a threat to the safety of family members.

Original languageEnglish
Publication statusAccepted/In press - 2016 Feb 18



  • Brachytherapy
  • Iodine-125
  • Prostate cancer
  • Radiation exposure
  • Radiation safety

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging

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