• Korean Journal of Environmental Agriculture
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• v.4 no.1
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• pp.18-24
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• 1985

A pot experiment was conducted to study the influence of potassium and cesium carrier on the uptake of radionuclide $Cs^{137}$ which is an element released usually from nuclear facilities, by paddy rice upon prolonged cropping of contaminated soils. The results are summarized as follows: 1) Visual toxic symptoms on the growth of rice plant due to treatment of radioactive cesium were not observed up to $20 {\mu}Ci/10Kg$ soil in a pot. 2) The yield and potassium content in rice plant were increased with potassium application, while the reverse was true for the calcium and magnesium. The addition of potassium to the soil markedly reduced $Cs^{137}$ uptake by rice plant but the addition of Cs carrier increased $Cs^{137}$ uptake. 3) Potassium and $Cs^{137}$ showed uniform distribution in all parts of plant and the contents of these two elements were high in the stems and leaves, and low in the heads. The ratio of $Cs^{137}$ to K was, however, not uniform in all parts of a plant. It was shown that this ratio was higher in the seed part, that is, chaff and hulled grain than in the leaves and stems. 4) $Cs^{137}$ absorption rate in rice plant was remarkably reduced with increase of potassium application and it was ranged from $0.02{\sim}0.47%$ in potassium non-treated plot to 0.01∼0.04% in plot treated with a concentration of 16Kg/10a. 5) The amount of $Cs^{137}$ and potassium uptake of rice plant depended on soil type. Uptake of $Cs^{137}$ by rice plant was higher in the soil with low pH and potassium content. The $Cs^{137}$ uptake by rice plant decreased as the potassium content and pH of soil was increased, but $Cs^{137}$ uptake increased when CEC and clay content in soil was high.

• Progress in Medical Physics
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• v.17 no.4
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• pp.232-237
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• 2006

The aim of this study was to develop the calculation algorithm of source strength of Ir-192 source In terms of the absorbed dose to water instead of an apparent activity (Ci). For this work the Multi Purpose Brachytherapy Phantom(MPBP) was developed, which was designed to locate the source and the chamber precisely at a specific position Inside the water phantom. The reference point of measurement was set at the 5 cm distance along the transverse axis of the source. For a brachytherapy source calibration, the absorbed dose to water calibration factor ($N_{D.W.Q}$) of an lonization chamber were determined and then apply standard protocols of absorbed dose to water. The calibration factor ($N_{D.W.Q}$) of the ion chamber (TM30013, PTW, Germany) was determined using the EGSnrcCPP Monte Carlo Code. The calculated calibration factor ($N_{D.W.Q}$) was 5.28 cGy/nC. The calculated factor was then used to determine the absorbed dose to water from which the air kerma strength for an Ir-192 source can be easily derived at the reference point (5 cm). The calculated air kerma strength showed discrepancies of -0.6% to +1.8% relative to the air kerma strength provided by the vendor, In this work we demonstrated that the air kerma strength ($S_k$) could be determined from the absorbed dose to water calibration factor for Ir-192 source. In audition, this source calibration method could be applied directly to the dose Calculation formalism of AAPM report TG-43.

• Tuberculosis and Respiratory Diseases
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• v.43 no.1
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• pp.54-62
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• 1996

Background: $^{99m}Tc$ MIBI(Methoxyisobutylisonitrile complex), a member of the isonitrile class of coordination compounds, is a lipophilic cation presently under investigation for clinical use as myocardial perfusion imaging agent and is widely used to detect myocardial infarction. Preliminary reports indicate that $T_1$-201 accumulate in human neoplasm and several authors reported $^{99m}Tc$ MIBI may also localized in primary malignant tumor and metastatic deposits from lung cancer. We evaluated the uptake of $^{99m}Tc$ MIBI in lung cancer and localization of mediastinal and other site metastasis, and compared the benign lesion of the lung. Method: Thirty four patients of lung cancer and ten patients of benign lung lesion were studied with chest CT and $^{99m}Tc$ MIBI Lung SPECT. $^{99m}Tc$ MIBI uptake ratio was assessed by TR/NL(Lung lesion/ Normal area), HT/NL (Heart/Normal area) and HT/TR(Heart/Lung lesion). Results: 1) All lung cancer patients showed increased uptakes of $^{99m}Tc$ MIBI in malignant lung lesion and Tc-99m MIBI uptake was also increased in mediastinal and lymph node metastasis except two cases. 2) There was significant different ratio of TR/NL between malignant and benign lesion, $3.79{\pm}1.82$ and $1.67{\pm}0.63$ on planar images, respectively(p<0.001). 3) There was no significant difference of $^{99m}Tc$ MIBI uptake ratio between squamous cell carcinoma, small cell carcinoma and adeno carcinoma($3.64{\pm}1.66$, $3.57{\pm}0.72$, $4.31{\pm}2.28$ respectively). Conclusion: $^{99m}Tc$ MIBI lung SPECT was useful in the localization of tumor and mediastinal or other site metastatic lesion in lung cancer and also in the differential diagnosis between benign and malignant lesion.

• The Korean Journal of Nuclear Medicine
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• v.28 no.2
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• pp.186-191
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• 1994

Tc-99m MIBI, a lipophilic cation, was reported as a useful agent for localization of lung cancer. The effect of radiation therapy on the uptake of Tc-99m MIBI in lung cancer, however, was not well evaluated. The aim of the present study was to elucidate the usefulness of Tc-99m MIBI SPECT in the localization and the assessment of radiotherapy in non-small cell lung cancer. Twenty patients(19 males and 1 female, mean age 59, 16 squamous cell ca and 4 adenoca) were studied with Tc-99m MIBI SPECT before radiation therapy. Eleven patients(10 males and 1 female, mean age 59, 8 squamous cell ca and 3 adenoca) were repeated the study 1 month after the completion of radiation therapy(mean dose 6453cGy). All patients showed positive uptakes of Tc-99m MIBI in their tumors. One patient showed a hot uptake in atelectatic area. There was no difference of Tc-99m MIBI uptakes between squamous cell ca and adenoca either on planar or tomographic images. Tc-99m MIBI uptake ratios of squamous cell ca and adenoca were $1.50{\pm}0.16$ and $1.45{\pm}0.15$ on planar images, and $2.73{\pm}0.46$ and $2.54{\pm}0.37$ on tomographic images, respectively. The concordance between radiological change(chest x-ray and CT) and change of Tc-99m MIBI uptakes was 9/11 (81.8% ). In conclusion, Tc-99m MIBI SPECT was useful in the localization of tumor and the assessment of radiation therapy in non-small cell lung cancer.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.21-30
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• 2022

Purpose: The purpose of this study is to evaluate the effectiveness of oral positioning stent, the BinkieRT^TM in radiation treatment for head and neck cancer patients in terms of tongue positions reproducibility, tongue doses and material properties. Materials and Methods: 24 cases using BinkieRT^TM during radiation treatments were enrolled. The tongue was contoured on planning CT and CBCT images taken every 3 days during treatment, and then the DSC and center of tongue shift values were analyzed to evaluate the reproducibility of the tongue. The tongue dose was compared in terms of dose distribution when using BinkieRT^TM and different type of oral stents (mouthpiece, paraffin wax). Randomly selected respective 10 patients were measured tongue doses of initial treatment plan for nasal cavity and unilateral parotid cancer. Finally, In terms of material evaluation, HU and relative electron density were identified in RTPS. Results: As a result of DSC analysis, it was 0.8 ± 0.07, skewness -0.8, kurtosis 0.61, and 95% CI was 0.79~0.82. To analyze the deviation of the central tongue shift during the treatment period, a 95% confidence interval for shift in the LR, SI, and AP directions were indicated, and a one-sample t-test for 0, which is an ideal value in the deviation(n=144). As a result of the t-test, the mean and SD in the LR and SI directions were 0.01 ± 0.14 cm (p→.05), 0.03 ± 0.25 cm (p→.05), and -0.08 ± 0.25 cm (p ←.05) in the AP direction. In the case of unilateral parotid cancer patients, the Dmean to the tongue of patients using BinkieRT^TM was 16.92% ± 3.58% compared to the prescribed dose, and 23.99% ± 10.86% of patients with Paraffin Wax, indicating that the tongue dose was relatively lower when using BinkieRT^TM (p←.05). On the other hand, among nasal cavity cancer patients, the Dmean of tongue dose for patients who used BinkieRT^TM was 4.4% ± 5.6%, and for those who used mouthpiece, 5.9% ± 6.8%, but it was not statistically significant (p→.05). The relative electron density of Paraffin Wax, BinkieRT^TM and Putty is 0.94, 0.99, 1.26 and the mass density is 0.95, 0.99 and 1.32 (g/cc), Transmission Factor is 0.99, 0.98, 0.96 respectively. Conclusion: The result of the tongue DSC analysis over the treatment period was about 0.8 and Deviation of the center of tongue shifts were within 0.2 cm, the reproducibility was more likely excellent. In the case of unilateral head and neck cancer patients, it was found that the use of BinkieRT^TM rather than Paraffin Wax or Putty can reduce the unnecessary dose irradiated to the tongue. This study might be useful to understand of BinkieRT^TM's properties and advantages. And also it could be another considered option as oral stent to keep the reproducibility of tongue and reducing dose during head and neck radiation treatments.