• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.1
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• pp.1-12
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• 2022

Bentonite is the most probable candidate to be used as a buffer in a deep geological repository with high swelling properties, hydraulic conductivity, thermal conductivity, and radionuclide sorption ability. Among them, the radionuclide sorption ability prevents or delays the transport of radionuclides into the nearby environment when an accident occurs and the radionuclide leaks from the canister, so it needs to be strengthened in terms of long-term disposal safety. Here, we proposed a surface modification method in which some inorganic additives were added to form NaP zeolite on the surface of the bentonite yielded at Yeonil, South Korea. We confirmed that the NaP zeolite was well-formed on the bentonite surface, which also increased the sorption efficiency of Cs and Sr from groundwater conditions. Both NaP and NaX zeolite can be produced and we have demonstrated that the generation mechanism of NaX and NaP is due to the number of homogeneous/heterogeneous nucleation sites and the number of nutrients supplied from an aluminosilicate gel during the surface modification process. This study showed the potential of surface modification on bentonite to enhance the safety of deep geological radioactive waste repository by improving the radionuclide sorption ability of bentonite.

• 대한핵의학회:학술대회논문집
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• 2001.05a
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• pp.4-10
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• 2001

The radionuclide therapy is a protocol for tumor control by administering radionuclides as the cytotoxic agents. Radionuclides concentrated at the site of cancerous lesion are expected to kill the cancerous cells with minimal injury to the normal tissue. The efficacy of every radionuclide treatment can be evaluated by examining the toxicity to the lesion differentiated from that to the normal tissue. Radiation dosimetry is the procedure of quantitating the energy absorbed by target volumes of interest. Dosimetric information plays an indicator of the expected radiation damage and thus the therapeutic efficacy. This paper summarizes the dosimetric aspects in radionuclide therapy in terms of radionuclides of use, radiation dosimetry methodology and considerations for each treatment in practical use.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.233-238
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• 1993

Esophageal motility was evaluated from the analysis of 10 consecutive swallows using liquid bolus containing 0.5 mCi of $^{99m}Tc$ tin colloid. We have reviewed our experience of esophageal transit study in the 20 normal volunteers and 55 patients with dysphagia that was not related to mechanical obstruction. The purpose of this study is to measure the esophageal transit in normal subjects and in patients with various esophageal motility disorders. The overall sensitivity and specificity of radionuclide esophageal transit study in detecting esophageal motor abnormality were compared with manometric results as a gold standard, which were 80% and 100% respectively. Radionuclide transit study is a safe, rapid, noninvasive test and suitable as a screening test for esophageal motor disorders.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.1
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• pp.1-8
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• 2007

This review discusses the production of alpha-particle-emitting radionuclides in radioimmunotherapy. Radioimmunotherapy labeled with alpha-particle is expected to be very useful for the treatment of monocellular cancer (e.g. leukemia) and micrometastasis at an early stage, residual tumor remained in tissues after chemotherapy and tumor resection, due to the high linear energy transfer (LET) and the short path length in biological tissue of alpha particle. Despite of the expected effectiveness of alpha-particle in radioimmunotherapy, its clinical research has not been activated by the several reasons, shortage of a suitable a-particle development and a reliable radionuclide production and supply system, appropriate antibody and chelator development. Among them, the establishment of radionuclide development and supply system is a key factor to make an alpha-immunotherapy more popular in clinical trial. Alpha-emitter can be produced by several methods, natural radionuclides, reactor irradiation, cyclotron irradiation, generator system and elution. Due to the sharply increasing demand of $^{213}Bi$, which is a most promising radionuclide in radioimmunotherapy and now has been produced with reactor, the cyclotron production system should be developed urgently to meet the demand.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.178-183
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• 1999

We report four cases of spontaneous intracranial hypotension that were investigated by radionuclide cisternography. $^{99m}Tc$-diethylenetriamine pentaacetic acid radionuclide cisternography of all our patients showed direct sign of cerebrospinal fluid leakage as well as indirect signs of less activity than expected over the cerebral convexities and rapid appearance of bladder activity. The headache of all patients was eventually controlled with bed rest and hydration.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.184-188
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• 1999

Although cerebrospinal fluid leakage is suggested as one of the causes of spontaneous intracranial hypotension, only a few cases with direct evidence of cerebrospinal fluid leakage on radionuclide cisternography have been reported in the literature. Indirect evidences of cerebrospinal fluid leakage such as early visualization of the soft tissue and bladder or delayed migration of radiotracer have been observed in most patients with spontaneous intracranial hypotension. We report a case of spontaneous intracranial hypotension in which cerebrospinal fluid leakage was directly demonstrated by early dynamic imaging of spine on radionuclide cisternography. We suggest that early dynamic imaging of spine is an important adjunctive procedure in detecting cerebrospinal fluid leakage in patients with spontaneous intracranial hypotension.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.2
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• pp.120-126
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• 2006

Radionuclide therapy has been continued for treatment of incurable diseases for past decades. Relevant evaluation of absorbed dose in radionuclide therapy is important to predict treatment output and essential for making treatment planning to prevent unexpected radiation toxicity. Many scientists in the field related with nuclear medicine have made effort to evolve concept and technique for internal radiation dosimetry in this review, basic concept of internal radiation dosimetry is described and recent progress in method for dosimetry is introduced.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.315-318
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• 1993

We experienced 7 cases of patients who were performed $^{99m}Tc$-methylene diphosphonate bone scintigraphy for the evaluation of diseases they had. Their bone scintigrams showed incidental radionuclide uptake in the gastrointestinal tracts and they had no special symptom or sign attributable to the findings. Case 1 showed radionuclide uptake in the stomach and both lung and the patient had suffered from hypercalcemia and azotemia. Case 3 and case 6 showed diffuse radionuclide uptake in the stomach and intestinal tract. Others showed diffuse or regional radionuclide uptake in the intestinal tracts. Radionuclide uptake in the gastrointestinal tract by $^{99m}Tc$-methylene diphosphonate is caused by a certain pathologic lesion but also can be seen in the normal gastrointestinal tract. So, one who reads bone scintigrams should be alert for the pathologic lesion in the gastrointestinal tract although one must interpretate with the concept of this normal variations.

• The Korean Journal of Nuclear Medicine
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• v.13 no.1_2
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• pp.7-14
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• 1979

Radionuclide cardiac angiography has distinct advantages in safety, patient comfort, cost and ease of performance. This method offers diagnostic accuracy equivalent to that of cardiac catheterization. By this method the qualitative and quantitative diagnosis of the cardiac shunts are available. Also for it is repeatable with ease and more physiologic, it has application in following pre- and post-operative shunt patients. We performed the radionuclide cardiac angiographies in 147 cases of heart diseases and 26 cases of normal group. 1. The detection of left-to-right shunt was possible in 22 of 24 patients, and 2 patients were not diagnosed due to small shunt amount. (Qp/Qs<1.3) In 21 patients of right-to-left shunt, all were diagnosed by radionuclide cardiac angiography. 2. With the pulmonary time-activity curve, $C_2/C_1$ ratio was calculated. In normal control group, a range of $C_2/C_1$ ratios of $21{\sim}38%$ was established with a mean value of $28.6{\pm}4.6%$. In patients with left-to-right shunts determined by catheterization data, the range of $C_2/C_1$ ratio was $33{\sim}90%$, with a mean value of $67.8{\pm}12.2%$. 3. In 8 cases of left-to-right shunt, $Q_p/Q_s$ ratios determined by radionuclide cardiac angiography were compaired with those of cardiac catheterization. The correlation coefficient was 0.907. (P<0.001) 4. Postoperative radionuclide cardiac angiographies were done in 21 cases. 3 of 13 patients with left-to-right shunts were found to have residual shunts. 8 patients with right-to-left shunts were confirmed to have no residual shunt.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.305-315
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• 2020

For geological disposal of radioactive wastes, a method was proposed to evaluate the radionuclide transport in the biosphere by calculating the elapsed time of nuclide migration. The radionuclides were supposed to be introduced from a natural barrier and reached a large surface water body following a groundwater flow in a shallow subsurface. The biosphere was defined as a shallow subsurface environment that included aquifers on a host rock. Using the proposed method, a calculation algorithm was established, and a computer code that implemented the algorithm was developed. The developed code was verified by comparing the simulation results of the simple cases with the results of the analytical solution and a public program, which has been widely used to evaluate the radiation dose using the radionuclide transport near the surface. A case study was constructed using the previous research for radionuclide transport from the hypothetical geological disposal repository. In the case study, the code calculated the mass discharge rate of radionuclide to a stream in the biosphere. Because the previous research only demonstrated the transport of radionuclides from the hypothetical repository to the host rock, the developed code in the present study could help identify the total transport of radionuclide along the complete pathway.