• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.269-277
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• 2010

Selenium is an essential micronutrient for normal body function and functions as an essential constituent of selenoproteins. This study was carried out to investigate effect of selenium on the formation of colonic aberrant crypt foci (ACF) and tumor formation in a mouse model. Five-week old ICR mice were acclimated for one week and fed different selenium diet (0.02, 0.1, and 0.5 ppm) for 12 weeks. Animals received three intraperitoneal injections of azoxymethane (10 mg/kg B.W. in saline for 3 weeks), followed by 2% dextran sodium sulfate in the drinking water for a week. There were four experimental groups, including a normal control group and three different selenium levels groups. After sacrifice, the total numbers of aberrant crypt (AC) and ACF were measured in the colonic mucosa after methylene blue staining. The number of tumors was noted for tumor incidence. Liver selenium concentration was measured using ICP-AES method. Gutathione peroxidase (GPx) activity was determined using a GPx assay kit in the liver and colon. TUNEL assay and proliferating cell nuclear antigen (PCNA) staining were performed to examine the cell apoptosis and cell proliferation, respectively. Immunohistochemistry of $\beta$-catenin was also performed on the mucous membrane tissue of colon. The activity of GPx in the liver and colon was decreased in the selenium-deficient diet group while it was increased in the selenium-overloaded diet group. Apoptotic positive cells were increased in the selenium-overloaded diet group but decreased in the selenium-deficient diet group. PCNA staining area was decreased in the selenium-overloaded diet group. In addition, the $\beta$-catenin protein level in the selenium-deficient diet group was increased but decreased in the selenium-overloaded diet group. These results indicate that dietary selenium might exert a modulating effect on colon cancer by inhibiting the development of ACF and colon tumor formation in this mouse model.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.63-70
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• 2011

Purpose: To evaluate the extent of pain response and objective response to palliative radiotherapy (RT) for bone metastases from hepatocellular carcinoma according to RT dose. Materials and Methods: From January 2007 to June 2010, palliative RT was conducted for 103 patients (223 sites) with bone metastases from hepatocellular carcinoma. Treatment sites were divided into the high RT dose and low RT dose groups by biologically effective dose (BED) of 39 $Gy_{10}$. Pain responses were evaluated using the numeric rating scale. Pain scores before and after RT were compared and categorized into 'Decreased', 'No change' and 'Increased'. Radiological objective responses were categorized into complete response, partial response, stable disease and progression using modified RECIST (Response Evaluation Criteria In Solid Tumors) criteria; the factors predicting patients' survival were analyzed. Results: The median follow-up period was 6 months (range, 0 to 46 months), and the radiologic responses existed in 67 RT sites (66.3%) and 44 sites (89.8%) in the high and low RT dose group, respectively. A dose-response relationship was found in relation to RT dose (p=0.02). Pain responses were 75% and 65% in the high and low RT dose groups, respectively. However, no statistical difference in pain response was found between the two groups (p=0.24). There were no differences in the toxicity profiles between the high and low RT dose groups. Median survival from the time of bone metastases diagnosis was 11 months (range, 0 to 46 months). The Child-Pugh classification at the time of palliative RT was the only significant predictive factor for patient survival after RT. Median survival time was 14 months under Child-Pugh A and 2 months under Child-Pugh B and C. Conclusion: The rate of radiologic objective response was higher in the high RT dose group. Palliative AT with a high dose would provide an improvement in patient quality of life through enhanced tumor response, especially in patients with proper liver function.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.122-125
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• 2004

In radiotherapy of tumors in liver, enough planning target volume (PTV) margins are necessary to compensate breathing-related movement of tumor volumes. To overcome the problems, this study aims to obtain patients' body movements by using a moving phantom and an ultrasonic sensor, and to develop respiration gating techniques that can adjust patients' beds by using reversed values of the data obtained. The phantom made to measure patients' body movements is composed of a microprocessor (BS II, 20 MHz, 8K Byte), a sensor (Ultra-Sonic, range 3 cm ${\sim}$3 m), host computer (RS232C) and stepping motor (torque 2.3Kg) etc., and the program to control and operate it was developed. The program allows the phantom to move within the maximum range of 2 cm, its movements and corrections to take place in order, and x, y and z to move successively. After the moving phantom was adjusted by entering random movement data(three dimensional data form with distance of 2cm), and the phantom movements were acquired using the ultra sonic sensor, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using guinea pigs, the real-time respiration gating techniques were drawn by operating the phantom with the reversed values of the data. The result of analyzing the acquisition-correction delay time for the three types of data values and about each value separately shows that the data values coincided with one another within 1% and that the acquisition-correction delay time was obtained real-time (2.34 ${\times}$ 10$^{-4}$sec). This study successfully confirms the clinic application possibility of respiration gating techniques by using a moving phantom and an ultra sonic sensor. With ongoing development of additional analysis system, which can be used in real-time set-up reproducibility analysis, it may be beneficially used in radiotherapy of moving tumors.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.85-93
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• 2012

Purpose: It is essential to minimize the respiratory-induced motion of involved organs in the Tomotherapy for tumor located in the chest and abdominal region. However, the application of breathing control system to Tomotherapy is limited. This study was aimed to investigate the possible application of the ABCHES system and its efficacy as a means of breathing control in the tomotherapy treatment. Materials and Methods: Five subjects who were treated with a Hi-Art Tomotherapy system for lung, liver, gallbladder and pancreatic tumors. All patients undertook trained on two breathing methodes using an ABCHES, free breathing methode and shallow breathing methode. When the patients could carry out the breathing control, 4D-CT scan was a total of 10 4D tomographic images were acquired. A radiologist resident manually drew the tumor region, including surrounding nomal organs, on each of CT images at the inhalation phase, the exhalation phase and the 40% phase (mid-inhalation) and average CT image. Those CT images were then exported to the Tomotherapy planning station. Data exported from the Tomotherapy planning station was analyzed to quantify characteristics of dose-volume histograms and motion of tumors. Organ motions under free breathing and shallow breathing were examined six directions, respectively. Radiation exposure to the surrounding organs were also measured and compared. Results: Organ motion is in the six directions with more than a 5 mm displacement. A total of 12 Organ motions occurred during free breathing while organ motions decreased to 2 times during shallow breathing under the use of Abches. Based on the quantitative analysis of the dose-volume histograms shallow breathing showed lower resulting values, compared to free breathing, in every measure. That is, treatment volume, the dose of radiation to the tumor and two surrounding normal organs (mean doses), the volume of healthy tissue exposed to radiation were lower at the shallow breathing state. Conclusion: This study proposes that the use of ABCHES is effective for the Tomotherapy treatment as it makes shortness of breathing easy for patients. Respiratory-induced tumor motion is minimized, and radiation exposure to surrounding normal tissues is also reduced as a result.

• Journal of Gastric Cancer
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• v.9 no.3
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• pp.110-116
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• 2009

Purpose: The aim of this study was to examine the usefulness of positron emission tomography (PET)-computed tomography (CT) in the pre-operative staging of gastric cancer. Materials and Methods: Between February 2006 and August 2008, PET-CT and CT were performed on 70 patients diagnosed with gastric cancer by gastrofiberscopic biopsy. The sensitivities, specificities, Positive predictive value (PPV), and negative predictive value (NPV) of PET-CT and CT imaging for the detection of gastric cancer TNM staging were compared. Results: The detection rates for the primary tumor were as follows: PET-CT, 81.4% (57/70); and CT, 42.9% (30/70). For both early gastric cancer (EGC) and advanced gastric cancer (AGC), PET-CT was more accurate than CT in detecting the lesions. As the size of the tumor exceeded 3 cm, the detection rate increased. The sensitivities, specificities, PPV, and NPV of PET-CT for lymph node staging were 55.6%, 81%, 86.2%, and 45.9%, while the sensitivities, specificities, PPV, and NPV of CT were 40.0%, 85.7%, 85.7% and 40%, respectively. One case of multiple liver metastasis and two cases of dual primary cancer (rectal and pancreatic cancers) were detected by PET-CT. PET-CT also had a higher detection rate for all histologic types of primary tumors. PET-CT was more accurate than CT in detecting primary gastric cancer lesions. The detection of nodal metastasis by PET-CT was similar to CT; small-sized tumors or EGC detection rates were not high. However, PET-CT provided additional information to detect distant metastases and dual primary cancers and reduced unnecessary laparotomies to detect peritoneal seeding or carcinomatosis. Conclusion: It would be useful to make a pre-operative diagnosis of gastric cancer and determine treatment if PET-CT were added to other routine pre-operative studies.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.373-384
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• 2001

Cellular proliferation is an intricately regulated process mediated by the coordinated interactions of critical growth control genes. Two of these factors in mammalian cells are the p53 and mdm-2 genes. A protein product of the mem-2 oncogene has been recently shown to associate with the protein encoded by the tumor suppressor gene p53. The p53 tumor suppressor protein is stabilized in response to DNA damage and other stress signals and causes the cell to undergo growth arrest or apoptosis, thus preventing the establishment of mutations in future cellular generations. Mutation or loss of p53 is a very common event in tumor progression. It occurs in about 50% of all tumors analysed including of colon, lung, breast and liver. The cellular mdm-2 gene, which has potential transforming activity that can be activated by overexpression, is amplified in a significant percentage of human sarcoma and in other mammalian tumors. Proteins encoded by the mdm-2 gene are able to bind to the p53 protein and, when overexpressed, can inhibit p53's transcriptional activation function, thus mdm-2 can act as a negative regulator of p53 function. Experimental study was performed to observe the relationship between p53 gene mutation and mdm-2 protein expression and apply the results to the clinical activity. 36 golden syrian hamster each weighing $60{\sim}80g$ were used and painted with 0.5% DMBA by 3 times weekly on the right buccal cheek(experimental side) for 6, 8, 10, 12, 14 and 16 weeks. Left buccal cheek(control side) was treated with mineral oil as the same manner to the right side. The hamsters were sacrificed on the 6, 8, 10, 12, 14 & 16 weeks. Normal and tumor tissues from paraffin block were examined for histology and immunohistochemistry observation, and were completely dissected by microdissection and DNA from both tissue were isolated by proteins K/phenol/chloroform extraction. Segments of the hamster p53 exons 5, 6, 7 and 8 were amplified by PCR using the oligonucleotide primers, and then confirmational change was observed by SSCP respectively. The results were as follows : 1. Dysplasia at 6 weeks, carcinoma in situ at 8 weeks and invasive carcinoma from 10 weeks could be observed in experimental groups. 2. p53 mutations were detected in 10 of the 36(28%) and the exons 6(6 of the 10 : 60%) was the most hot spot area among the highy conserved region(exons 5, 6, 7 & 8). 3. Immunohistochemical study confirmed 22 of the 36(61%) of p53 expression involving 10 of p53 mutations. 4. mdm-2 expression of was showed in 3 of the 36(8%) involving 1 of the 22 of p53 expression and 2 of the 14 of p53 non-expression. From the above results, mutation of p53 gene or expression of p53 protein may have the influence of the DMBA induced carcinoma of hamster buccal pouch but the expression of mdm-2 protein may not have relationship with tumorigenesis.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.251-256
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• 2000

Purpose : To evaluate efficacy and complication of stereotactic radiosurgery using stereotactic body frame. Methods and Materials :From December 1997 to June 1999, 11 patients with primary and metastatic tumors were treated with stereotactic radiosurgery using stereotactic body frame(Precision TherapyTu). Three patients were treated with primary hepatoma and seven with metastatic tumor from liver, lung, breast, trachea and one with arteriovenous malformation on neck. We used vacuum pillow for immobilization and made skin marker on sternum and tibia area with chest marker and leg marker. Diaphragm control was used for reducing movement by respiration. CT-simulation and treatment planning were peformed. Set-up error was checked by CT-Simulator before each treatment. Dose were calculated on the 80$\~$90$\%$ isodose of isocenter dose and given consecutive 3 fractions for total dose of 30 Gy (10 Gy/fraction). Results :Median follow-up was 12 months. One patient (9$\%$) showed complete response and four Patients (36$\%$) showed partial response and others showed stable disease. Planning target volumes (PTV) ranged from 3 to 111 cc (mean 18.4 n). Set-up error was within 5 mm in all directions (X, Y, Z axis). There was no complication in all patients. Conclusion :In Primary and metastatic tumors, stereotactic body frame is very safe, accurate and effective treatment modality.

• Radiation Oncology Journal
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• v.22 no.4
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• pp.316-324
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• 2004

Purpose : In radiotherapy of tumors in liver, enough planning target volume (PTV) margins are necessary to compensate breathing-related movement of tumor volumes. To overcome the problems, this study aims to obtain patients' body movements by using a moving phantom and an ultrasonic sensor, and to develop respiration sating techniques that can adjust patients' beds by using reversed values of the data obtained. Materials and Methods : The phantom made to measure patients' body movements is composed of a microprocessor (BS II, 20 MHz, 8K Byte), a sensor (Ultra-Sonic, range $3\~3$ m), host computer (RS232C) and stepping motor (torque 2.3 Kg) etc., and the program to control and operate it was developed. The program allows the phantom to move within the maximum range of 2 cm, its movements and corrections to take place In order, and x, y and z to move successively. After the moving phantom was adjusted by entering random movement data (three dimensional data form with distance of 2 cm), and the phantom movements were acquired using the ultra sonic sensor, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using guinea pigs, the real-time respiration gating techniques were drawn by operating the phantom with the reversed values of the data. Results : The result of analyzing the acquisition-correction delay time the three types of data values and about each value separately shows that the data values coincided with one another within $1\%$ and that the acquisition-correction delay time was obtained real-time $(2.34{\times}10^{-4}sec)$. Conclusion : This study successfully confirms the clinic application possibility of respiration gating techniques by using a moving phantom and an ultrasonic sensor. With ongoing development of additional analysis system, which can be used in real-time set-up reproducibility analysis, it may be beneficially used in radiotherapy of moving tumors.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.1
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• pp.34-38
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• 2017

Purpose During PET/CT examinations, the movements of internal organs caused by respiration are captured in images during multiple breathing cycles, resulting in the increases in tumor size and effects on SUV. Respiratory synchronized systems were used to evaluate tumor sizes and SUV changes. Materials and Methods Biograph mCT 64 was used for the equipment, and RPM and Anzai systems were used for the respiratory synchronized systems. We used point source and micro-phantom for an experimentation. We were performed on 12 patients who had solid tumors discovered at the base of the lung or at the top of the liver from August through September 2016. The PET images of the exhalation-to-breathing state and the CT images of the post-exhalation suspension state were gained to evaluate changes in radioactivity concentration (KBq/mL), SUVmax, cylinder diameter (mm), and tumor diameter (cm) under the conventional Static, RPM, and Anzai methods. Results The result of measuring the radioactivity concentration of the point source was RPM 94% and Anzai 91% against Static, respectively. In the two cylinders of different radioactivity in the micro-phantom, the SUVmax increased to RPM 61% and 78%, and Anzai 58% and 77% against Static, whereas the cylinder diameters decreased by RPM -26% and -28%, and Anzai -28% and -26%, each respectively. Among the patients, the SUVmax increased from a minimum of RPM 8.2% to a maximum of 94.4% against Static, and from a minimum of Anzai 7.6% to a maximum of 68.3%, respectively. As for the tumor diameters, a minimum of RPM -7.6% to a maximum of -28.9% were achieved, while the Anzai fell by a minimum of -9.6% to a maximum of -27.7%, respectively. There was no significant difference discovered in the phantom study between the RPM and Anzai, yet there was a meaningful difference in the patients' tumors (P<0.05). Conclusion The respiratory synchronized systems of RPM and Anzai yielded no significant difference in the phantom study in which the respiration was executed at regular intervals. However, it was discovered that the patients had a meaningful difference for the irregular respiratory cycle and inter-system differences. Still, the respiratory synchronized systems would be useful for the accurate diagnosis and SUV measurement as the tumor decreased in size against the existing Static and the SUV increased.

• Tuberculosis and Respiratory Diseases
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• v.68 no.1
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• pp.1-5
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• 2010

Background: To analyze the result of $^{18}F-FDG$ positron emission tomography (PET) in patients with a concomitant malignancy and tuberculoma in a tuberculosis (TB)-endemic area. Methods: Twelve patients with a concomitant malignancy and tuberculoma, who underwent whole-body $^{18}F-FDG$ PET, were evaluated retrospectively. The maximal standardized uptake values (SUVmax) of the malignancy and tuberculoma were compared. In 6 patients, $^{18}F-FDG$ PET was repeated during the anti-TB treatment and the changes in SUVmax were analyzed. Results: Of the 12 patients, 10 were male. The mean age was $67.2{\pm}7.9$ years. Tuberculomas were located in the lung (n=10) and lymph nodes (n=2), and tumors were located in the lung (n=6), colon (n=3), stomach (n=1), ovary (n=1) and liver (n=1). Although the mean SUVmax of malignant lesions was higher than that of tuberculomas ($5.2{\pm}3.2$ vs $3.5{\pm}2.0$), the difference was not significant. In 4 patients, the SUVmax was higher in the tuberculoma than the tumor. After anti-TB treatment in 6 patients, the mean SUVmax of the tuberculomas decreased significantly, from $3.5{\pm}2.0$ to $1.6{\pm}0.9$ (p=0.028). Conclusion: In patients with a concomitant malignancy and tuberculoma, SUVmax alone could not differentiate between them. However, $^{18}F-FDG$ PET may be useful in monitoring the response to anti-TB treatment.