• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.526-534
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• 2009

Purpose: We retrospectively investigated the diagnostic performance of $^{18}F$-fluorodeoxyglucose positron emission tomography (PET) and PET/CT for cancer detection in asymptomatic health-check examinees. Materials and Methods: This study consisted of 5091 PET or PET/CT conducted as part of annual health examination at one hospital from March 1998 to February 2008. To find the incidence of cancers, medical records of the subjects were thoroughly reviewed for a follow-up period of one year. The patterns of formal readings of PET and PET/CT were analyzed to assess the sensitivity and specificity for cancer detection. The histopathology and stage of the cancers were evaluated in relation to the results of PET. Results: Eighty-six cancers (1.7%) were diagnosed within one year after PET or PET/CT. When PET and PET/CT results were combined, the sensitivity was 48.8% and specificity was 81.1% for cancer detection. PET only had a sensitivity of 46.2% and a specificity of 81.4%, and PET/CT only had a sensitivity of 75.0% and a specificity of 78.5% respectively. There were no significant differences in cancer site, stage and histopathology between PET positive and PET negative cancers. In 19.3% of formal readings of PET and PET/CT, further evaluation to exclude malignancy or significant disease was recommended. Head and neck area and upper gastrointestinal tract were commonly recommended sites for further evaluation. Conclusions: PET and PET/CT showed moderate performance for detecting cancers in asymptomatic adults in this study. More experience and further investigation are needed to overcome limitations of PET and PET/CT for cancer screening.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.760-765
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• 1998

Background: Glucose uptake has been found to be increased in cancer cells, and FDG-PET imaging is used for diagnosis of cancer using this phenomenon. However, the exact mechanism of increased glucose uptake in cancer cells has not been clarified. Recent studies demonstrated the presence of glucose transporter(GLUT) mRNA expression in gastrointestinal cancer and head and neck cancer, and suggested that GLUT may be associated with glucose uptake in cancer cells. In lung cancer cells, glucose metabolism is also known to be increased. We evaluated GLUT mRNA expression in human lung cancer cell lines in order to find out the mechanism of increased glucose uptake in lung cancer. Method: Total RNA was isolated from 15 human lung cancer cell lines and immortalized bronchial epithelial cell line(BEAS-2B). After electrophoresis of $20{\mu}g$ total RNA, Northern blot analysis was done using GLUT1 cDNA and GLUT3 cDNA as probes. Results: Thirteen of 14 human lung cancer cell lines expressed GLUT1 mRNA and 10 of 14 human lung cancer cell lines expressed GLUT3 mRNA. Eight human lung cancer cell lines expressed both GLUT mRNAs. BEAS-2B expressed GLUT1 mRNA and did not express detectable GLUT3 mRNA. Conclusion: The increase of glucose metabolism in lung cancer may be associated with GLUT1 and GLUT3 expression.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.511-517
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• 1995

Bone scan is a very sensitive diagnostic imaging test for detecting bone and joint disorders. So it might be useful in the diagnosis of temporomandibular disorders of the joint origin. Thus, the effectiveness of bone scan for detecting temporomandibular joint(TMJ) diseases and differentiating the TMJ disc displacement from the TMJ arthritis was evaluated. Bone scan was done in 21 patients with TMJ disc displacement(13 unilaterally affected, 8 bilaterally affected), 25 patients with TMJ arthritis(23 unilateral, 3 bilateral), and 39 volunteers with no signs, symtoms, or history of TMJ disease. TMJ simple uptake rate(SUR) and difference of both TMJ SUR were calculated from the 100,000 count lateral image of head and neck region in 99mTc MDP bone scan. Transcranial and panorama X-ray examination was also done in all patients. TMJ SUR(%) were $1.673{\pm}0.606$ in TMJs affected with arthritis, $1350{\pm}0.351$ in TMJs affected with disc displacement, and $1.084{\pm}0.172$ in TMJs of controls. Significant differences were demonstrated among them(p<0.01) Difference of bith TMJ SUR was highest in patients with unilateral TMJ arthritis($0.608{\pm}$0.533, p<001), and there is no significant difference between that of controls and that of unilateral TMJ dist displacement patients($0.062{\pm}0.063$ vs $0.122{\pm}0.100$). TMJ SUR of Joint with bone change on X-ray finding was not significantly different from that of joint with normal X-ray finding. Those in patients with unilateral TMJ disc displacement(696% and 87% vs 23.1% and 23%). The proportions of patients with increased TMJ SUR and difference of both TMJ SUR(>mean+2SD of controls) in unilateral TMJ arthritis patients were significantly higher than those in patients with unilateral TMJ disc displacement(69.6% and 87% vs 23.1% and 23%). Conclusively, bone scan nay help to detect TMJ disease and differentiate TMJ disc displacement from TMJ arthritis.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.167-174
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• 2015

Purpose : The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Materials and Methods : Test was used for TrueBeam STx$^{TM}$ (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). Results : The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Conclusion : Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.9-15
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• 2006

Purpose: Previous studies have not showed consistent results for the level of expression of sodium/iodide symporter (NIS) in thyroid diseases, especially malignant tumor. We undertook this study to evaluate the distribution of NIS expression in malignant thyroid diseases and compare with that in benign thyroid disease. Materials and Methods: Total patients were 119 cases (Men 15, $48{\pm}13$ yrs). Total number of samples were 205 pieces. In malignant thyroid disease, there were 153 samples: 90 in papillary carcinoma, 4 in follicular carcinoma, 2 in medullary carcinoma and 57 in metastatic lymph node. In benign thyroid disease, there were 52 samples: 36 in goiter/cyst, 11 in thyroiditis and 5 in follicular adenoma. Using immunohistochemical methods, we probed 205 samples with monoclonal anti-NIS Ab. Grading of staining was stored as 0 (negative or absent), 1 (weakly positive), 2 (moderately positive) or 3 (strongly positive). Expression rate (ER) of NIS positivity in individual disease entity was expressed as percentage of total number divided by number in 2 plus 3 grade. Results: ERs of malignant thyroid diseases were 63% in papillary carcinoma, 81% in metastatic lymph node, 71% in follicular carcinoma and 100% in medullary carcinoma. ERs of benign thyroid disease were 53% in goiter/cyst, 64% in thyroiditis and 40% in follicular adenoma. ER of malignant thyroid diseases was higher than benign thyroid diseases (71% vs 54%). Grading of NIS expression in papillary carcinoma or goiter/cyst was heterogeneously distributed in considerable cases. Normal tissue also showed heterogeneous distribution of NIS expression, which was not correlated with that of primary lesion. Conclusion: In papillary thyroid carcinoma, distribution of NIS expression was heterogeneous and increased, and not different compared with that of benign thyroid disease.

• Progress in Medical Physics
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• v.24 no.2
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• pp.85-91
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• 2013

At present, megavoltage computed tomography (MVCT) is the only method used to correct the position of tomotherapy patients. MVCT produces extra radiation, in addition to the radiation used for treatment, and repositioning also takes up much of the total treatment time. To address these issues, we suggest the use of a video image-guided setup (VIGS) system for correcting the position of tomotherapy patients. We developed an in-house program to correct the exact position of patients using two orthogonal images obtained from two video cameras installed at $90^{\circ}$ and fastened inside the tomotherapy gantry. The system is programmed to make automatic registration possible with the use of edge detection of the user-defined region of interest (ROI). A head-and-neck patient is then simulated using a humanoid phantom. After taking the computed tomography (CT) image, tomotherapy planning is performed. To mimic a clinical treatment course, we used an immobilization device to position the phantom on the tomotherapy couch and, using MVCT, corrected its position to match the one captured when the treatment was planned. Video images of the corrected position were used as reference images for the VIGS system. First, the position was repeatedly corrected 10 times using MVCT, and based on the saved reference video image, the patient position was then corrected 10 times using the VIGS method. Thereafter, the results of the two correction methods were compared. The results demonstrated that patient positioning using a video-imaging method ($41.7{\pm}11.2$ seconds) significantly reduces the overall time of the MVCT method ($420{\pm}6$ seconds) (p<0.05). However, there was no meaningful difference in accuracy between the two methods (x=0.11 mm, y=0.27 mm, z=0.58 mm, p>0.05). Because VIGS provides a more accurate result and reduces the required time, compared with the MVCT method, it is expected to manage the overall tomotherapy treatment process more efficiently.