• Journal of Radiation Protection and Research
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• v.9 no.2
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• pp.112-117
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• 1984

A lot of radioisotopes are applied to medical fields. It's very important to measure the activities on airborne radioiodine discharged in air from $Na^{131}I$ solutions and from patients treated with radioiodine. Also surface decontamination is another one important problem to be completly solved in the isotope laboratory where there is always the possibility of radiation contamination. The Authors measured the activities on airborne radioiodine with RI collector and scintillation counter. 1. The mean accumulative activity of airborne radioiodine discharged into air from $Na^{131}I$ solution was measured as $1.3{\times}10^{-3}/hr$ rate, and the maximum value was $1.8{\times}10^{-3}/hr$. 2. Radioactivity rate per hour of airborne iodine discharged into air from patients treated with $Na^{131}I$ was measured as $6.2{\times}10^{-5}/hr$ at 8 hour after administration of radioiodine and decreased into $2{\times}10^{-6}/hr$ after 24 hour. 3. Metalic surfaces such as stainless steel or aluminum are decontaminated 5 to 6 times more rapidly than wood and concrete surfaces. 4. Decontamination with wet wiping with detergent was 9 to 10 times more rapidly than dry wiping method, but dry wiping was useful for the first step to prevent spreading and flowing from liquid radioactive materials.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.28-34
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• 2010

Purpose: According to increment of thyroid cancer recently, patients of high dose radioiodine therapy were accumulated. Taking into consideration the acceptance capability in the current facility, this study is to calculate the maximum value of high dose radioiodine therapy in patients for treatment. Materials and Methods: The amount and radioactivity of waste water discharged from high dose radioiodine therapy in patients admitted at present hospital as well as the radiation density of the air released into the atmosphere from the high dose radioiodine therapy ward were measured. When the calculated waste water's radiation and its density in the released air satisfies the standard (management standard for discharge into water supply 30 Bq/L, management standard for release into air 3 $Bq/m^3$) set by the Ministry of Education, Science and Technology, the maximum value of treatable high dose radioiodine therapy in patients was calculated. Results: When we calculated in a conservative view, the average density of radiation of waste water discharged from treating high dose radioiodine therapy one patient was 8 MBq/L and after 117 days of diminution in the water-purifier tank, it was 29.5 Bq/L. Also, the average density of radiation of waste water discharged from treating high dose radioiodine therapy two patients was 16 MBq/L and after 70 days of diminution in the water-purifier tank, it was 29.7 Bq/L. Under the same conditions, the density of radiation released into air through RI Ventilation Filter from the radioiodine therapy ward was 0.38 $Bq/m^3$. Conclusion: The maximum value of high dose radioiodine therapy in patients that can be treated within the acceptance capability was calculated and applied to the current facility, and if double rooms are managed by improving the ward structure, it would be possible to reduce the accumulated treatment waiting period for radioiodine therapy in patients.

• Progress in Medical Physics
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• v.27 no.3
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• pp.156-161
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• 2016

When air discharged from a radioisotope production facility is contaminated with radiation, the public may be exposed to radiation. The objective of this study is to manage such radiation exposure. We measured the airborne radioactivity concentration at a 30 MeV cyclotron radioisotope production facility to assess whether the exhaust gas was contaminated. Additionally, we investigted the radioactive contamination of the air filter for efficient air purification and radiation safety control. To measure the airborne radiation concentration, specimens were collected weekly for 4 h after the beginning of the radioisotope production. Regarding the air purifier, five specimens were collected at different positions of each filter-pre-filter, high-efficiency particulate air filter, and charcoal filter-installed in the cyclotron production room. The concentrations of F-18, I-123, I-131, and Tl-201 generated in the radioiodine production room were $13.5Bq/m^3$, $27.0Bq/m^3$, $0.10Bq/m^3$, and $11.5Bq/m^3$, respectively; the concentrations of F-18, I-123, and I-131 produced in the radioisotope production room were $0.05Bq/m^3$, $16.1Bq/m^3$, and $0.45Bq/m^3$, correspondingly; and those of F-18, I-123, I-131, and Tl-201 generated in the accelerator room were $2.07Bq/m^3$, $53.0Bq/m^3$, $0.37Bq/m^3$, and $0.15Bq/m^3$, respectively. The maximum radiation concentration of I-123 generated in the radioiodine production room was 1,820 Bq/g, which can be disposed after 2 days. The maximum radiation concentration of Tl-202 generated in the radioisotope production room was 205 Bq/g, and this isotope must be stored for 53 days. The I-123 generated in the radioiodine production room had a maximum concentration of 1,530 Bq/g and must be stored for 2 days. The maximum radiation concentration of Na-22 generated in the radioisotope production room was 0.18 Bq/g and this isotope must be disposed after 827 days. To manage the exhaust, the efficiency of air purification must be enhanced by selecting an air purifier with a long life and determining the appropriate replacement time by examining the differential pressure through systematic measurements of the airborne radiation contamination level.

• Journal of Radiation Protection and Research
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• v.19 no.1
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• pp.69-80
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• 1994

The TCMI(Three-Compartment Model for iodine) computer code has been developed, which is based on the three-compartment model and the respiratory model recommended in ICRP publication 54. This code is able to evaluate the thyroid burden, dose equivalent, committed dose equivalent and urinary excretion rate as time-dependent functions from the input data: working time and the radioiodine concentration in air. Using the TCMI code, the time-dependent thyroid burdens, the thyroid doses and the urinary excretion rates were calculated for three specific exposure patterns : acute, chronic and periodic. Applicability as an internal dose evaluation method has been assessed by comparing the results with some operational experiences. Simple equations and tables are provided to be used in the evaluation of the thyroid burden and the resulting doses for given I-131 concentration in air and the working time.

• Journal of radiological science and technology
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• v.39 no.3
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• pp.385-390
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• 2016

Radioactive iodine treatment that uses the 2 people isolation room is to cause unnecessary radiation exposure between patients. This research is to be tested safety of 2 people Isolation treatment room and dose-rate through conservative perspective except physiology characteristic and biology information on the assumption that patient have iodine without excretion in 2 people isolation treatment room. This research shows that 364 keV gamma rays emitted by the radioiodine was to determine that the air layer about 30 cm or lead shield 3 mm a half-layer. In addition, In addition, patients in the distance, and lead shielding, length of hospital stay (48 hours) for external radiation exposure that is received from the other patients, two of treatment as appears to be lower than the legal isolation standard dose less than 5 mSv isolation room effective analyzed that manageable.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.653-659
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• 2019

The purpose of this study is to measure the (air dose rate of radiation dose) the discharged patient who was administrated high dose $^{131}I$ treatment, and to predict exposure radiation dose in public person. The dosimetric evaluation was performed according to the distance and angle using three copper rings in 30 patients who were treated with over 200mCi high dose Iodine therapy. The two observer were measured using a GM surverymeter with 8 point azimuth angle and three difference distance 50, 100, 150cm for precise radion dose measurement. We set up three predictive simulations to calculate the exposure dose based on this data. The most highest radiation dose rate was showed measuring angle $0^{\circ}$ at the height of 1m. The each distance average dose rate was used the azimuth angle average value of radiation dose rate. The maximum values of the external radiation dose rate depending on the distance were $214{\pm}16.5$, $59{\pm}9.1$ and $38{\pm}5.8{\mu}Sv/h$ at 50, 100, 150cm, respectively. If high dose Iodine treatment patient moves 5 hours using public transportation, an unspecified person in a side seat at 50cm is exposed 1.14 mSv radiation dose. A person who cares for 4days at a distance of 1 meter from a patient wearing a urine bag receives a maximum radiation dose of 6.5mSv. The maximum dose of radiation that a guardian can receive is 1.08mSv at a distance of 1.5m for 7days. The annual radiation dose limit is exceeded in a short time when applied the our developed radiation dose predictive modeling on the general public person who was around the patients with Iodine therapy. This study can be helpful in suggesting a reasonable guideline of the general public person protection system after discharge of high dose Iodine administered patients.