The Radiation Dose Measurement of I-131 Therapy Room of Thyroid Cancer

초록

Background: We measured radiation dose-rate, derived air concentration (DAC), and surface contamination dose in I-131 therapy room (TR) for the comparison of dose limit of the atomic law from the current Korean government radiation safety regulation. Methods: Radiation activity in I-131 TR was measured by Chiyoda techno corp., ltd. Japan. We attached environmental glass badges in I-131 TR (12 points) for the measurement of radiation dose-rate from July 6th to August 1st, 2008. To measure DAC, we sucked the air in I-131 TR (2 points) through the air filter paper, and evaluated it using the gamma radioactivity measuring method. To measure surface contamination dose, we sampled from I-131 TR (2 points) by smearing, and investigated with gamma nuclide using a NaI (Tl) scintillation counter. Results: The radiation dose-rates of I-131 TR were 0.06-0.33 mSv/wk (dose limit: 0.4 mSv/wk). DAC of I-131 TR were 1.3-1.4 x 10-5 Bq/cm3 (dose limit: 8x10-4 Bq/cm3). Surface contamination dose in I-131 TR were 1.1–1.3 Bq/cm2 (dose limit: 4 Bq/cm2). Conclusions: Radiation dose-rate, DAC, and surface contamination dose of TR were lower than those of dose limit of related laws. Radiation workers and the public in our hospital were safe from radiation exposure of I-131 TR.