• Nuclear Engineering and Technology
• /
• v.54 no.8
• /
• pp.2852-2858
• /
• 2022

A proton therapy facility is under development at Huazhong University of Science and Technology (HUST). To meet the need for fast energy changes during treatments, a beamline control system (BCS) has been designed and implemented. The BCS coordinates and controls various beamline devices by adopting a distributed architecture divided into three layers: the client, server, and device layers. Among these, the design of the server layer is the key to realize fast energy changes. The server layer adopts the submodule programming paradigm and optimizes the data interface among modules, allowing the main workflow to be separated from the device workflow and data. Furthermore, this layer uses asynchronous, multithreaded, and thread-locking methods to improve the system's ability to operation efficiently and securely. Notably, to evaluate the changing energy status over time, a dynamic node update method is adopted, which can dynamically adjust the update frequency of variable nodes. This method not only meets the demand for fast updates on energy changes but also reduces the server's communication load in the steady state. This method is tested on a virtual platform, and the results are as expected.

• Nuclear Engineering and Technology
• /
• v.53 no.1
• /
• pp.258-265
• /
• 2021

High levels for noise and a loss of true signal make the quantitative interpretation of nuclear medicine (NM) images difficult. An application of profile optimization using a sigmoidal function in this study was used to acquire the NM images with high quality. And the images were acquired by using three kinds of reconstruction method using each same sinogram: a standard filtered back-projection (FBP), an iterative reconstruction (IR) technique, and the sigmoidal function profile optimization (SFPO). Comparison of image according to reconstruction method was performed to show a superiority of the SFPO for imaging. The images reconstructed by using the SFPO showed an average of 1.49 times and of 1.17 times better in contrast than the results obtained using the standard FBP and the IR technique, respectively. Higher signal to noise ratios were obtained as an average of 12.30 times and of 3.77 times than results obtained using the standard FBP and the IR technique, respectively. This study confirms that reconstruction with SFPO (vs FBP and vs IR) can lead to better lesion detectability and characterization with noise reduction. It can be developed for future reconstruction technique for the NM imaging.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.3 no.1
• /
• pp.23-29
• /
• 2000

Purpose: It has recently been recognized that Helicobacter pylori (H. pylori) is an important factor in the pathogenesis of recurrent abdominal pain (RAP) in children. But, the best treatment for H. pylori infection is still unsettled. This study was performed to evaluate the efficacy of 2 weeks dual therapy with proton pump inhibitor (PPI) and amoxicillin for children with H. pylori infection associated with RAP. Method: Our study included 24 children with RAP who were H. pylori positive assessed by CLO test and histologic examination (silver stain). We used the regimen consisted of PPI (omeprazole, 0.7 mg/kg/day) and amoxicillin (50 mg/kg/day) for 2 weeks to eradicate H. pylori. Eradication of H. pylori was determined 4 weeks after the termination of treatment using the CLO test and histologic examination. Results: The endoscopic diagnoses of patients were nodular gastritis in 11 cases, superficial gastritis in 7 cases, peptic ulcer in 4 cases and normal finding in 2 cases. H. pylori was eradicated in 12 cases by omeprazole and amoxicillin dual therapy for 2 weeks and the eradication rate was 50%. In 4 of 12 children in whom H. pylori had not been eradicated with that regimen, we successfully eradicated H. pylori with other regimens of which 2 or 3 drugs among omeprazole, amoxicillin, clarithromycin, colloidal bismuth subcitrate ($Denol^{(R)}$) and metronidazole were used. Conclusion: The dual therapy with PPI and amoxicillin for 2 weeks had no clear advantage over other regimens for the eradication of H. pylori infection in children. We concluded that the combi-nation of PPI and amoxicillin for 2 weeks is not so good for H. pylori eradication as other commonly used regimens.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.20 no.2
• /
• pp.141-147
• /
• 2009

Background and Objectives: Although laryngopharyngeal reflux disease (LPRD) is a widely recognized disease in the field of otolaryngology, controversies still exist regarding the diagnosis and treatment for it. The purpose of this survey was to find out current trends in diagnosis and management of LPRD among Korean otolaryngologists. Materials and Method: Questionnaires were obtained from 26 Korean otolaryngology specialists by electronic balloting, and 46 members of the Korean Society of Head and Neck Surgery (KSHNS) bye-mail. Survey participants were asked about their preferences in diagnostic policy, duration/dosage of antireflux treatment, and their familiarity to the reflux symptom index (RST) and the reflux finding scores (RFS). Results: The majority of the survey participants (64%) preferred empiric therapy trial with proton pump inhibitors (PPIs) based on patients' symptoms and their laryngeal findings. PPIs alone (27%) or PPIs with prokinetics (32%) were usually prescribed as a first line treatment mostly with once daily schedule in the morning before meal and for less than 4 months of duration (86%). More than 90% of participants were aware of the RSI and RFS, but less than 50% of them were actually using those items in the clinics. Conclusion: Most of Korean otolaryngologists who participated in this survey answered that they prefer starting empirical treatments with proton pump inhibitors mainly based on the patient's symptoms and their laryngeal findings.

• Journal of Yeungnam Medical Science
• /
• v.30 no.2
• /
• pp.141-144
• /
• 2013

Hyperplastic gastric polyps (HPPs) are the most common type of gastric polyps. They are assumed to be caused by chronic inflammation and regenerative proliferation, although this has not been clearly investigated yet. Many studies suggested the development of fundic gland polyps and carcinoid during long-term proton pump inhibitor (PPI) therapy, but the relationship between PPIs and HPPs is still unclear. We encountered a patient who showed aggravation of HPPs after long-term use of PPIs. A 58-year-old male patient with liver cirrhosis visited our hospital because of hematemesis. We started PPI medication after confirming esophageal variceal bleeding and duodenal ulcer with blood clot in its base via emergency endoscopy. He took PPIs for three years because of an intractable duodenal ulcer. There was a marked increase in the size of the pre-existing polyps and in the development of new polyps. We presumed that the PPIs caused the aggravation of the HPPs, so we stopped their administration. After five months, the HPPs shrank and the polyps were partially degraded. More prospective studies are needed to investigate the relationship between HPPs and PPIs.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.16 no.1
• /
• pp.15-18
• /
• 2005

Background and Objectives : To determine the changes of reflux symptoms and laryngoscopic findings of patients with laryngopharyngeal reflux (LPR) on the duration of proton pump inhibitor medication. Materials and Methods : From Feb 2003 to Nov 2004, 58 patients who were diagnosed with LPR by 24-hour double-probe pH monitoring were enrolled. All patients were treated with proton pump inhibitor and followed up for 8 weeks at least. The response of symptoms and laryngoscopic findings of patients were assessed with reflux symptom index (RSI) and reflux finding score (RFS) before treatment and 2, 4, 8, 12, 16, 20 weeks after treatment. Results : The symptoms of patients with LPR were improved significantly at 2, 4, 8 weeks of treatment. The laryngoscopic findings of patients with LPR were improved significantly at 4 and 12 weeks of treatment. There was no correlation between improvement of reflux symptoms and laryngoscopic findings. Conclusions : The laryngoscopic findings of LPR patients were improved more slowly than reflux symptoms. Based on our results, anti-reflux therapy might be continued at least for 3 months until the improvement of laryngoscopic findings.

• Korean Journal of Clinical Pharmacy
• /
• v.26 no.1
• /
• pp.46-52
• /
• 2016

Background: The use of acid suppressive agents became a standard therapy in an intensive care unit (ICU) to prevent stress related gastrointestinal mucosal damage. However, the risk of infectious diseases has been concerned. Objective: The study was to determine the differences between histamine 2 receptor antagonists (H2RA) and proton pump inhibitors (PPI) in incidence of nosocomial pneumonia and pseudomembranous colitis (PMC) by Clostridium difficile with patients in ICU. Methods: This is a retrospective comparative study including patients admitted to the ICU who were at least 18 years of age and stayed for more than 48hrs from August 1, 2014 to January 31, 2015. The propensity score analysis and propensity matched multivariable logistic regression were used in analyzing data to control for confounders. Results: A total of 155 patients were assessed. H2RA were prescribed in 110 (53.9%) and PPI were in 45 (22.1%). Nosocomial pneumonia developed in 37 (23.9%); 25 (22.7%) were on H2RA and 12 (26.7%) were on PPI. The unadjusted incidence of nosocomial pneumonia was slightly higher in the patients with PPI (odds ratio (OR) 1.24; 95% confidence interval (CI): 0.54-2.71) compared to them with H2A. After adjusting with propensity score, the adjusted OR with PPI was 1.35 (95% CI: 0.44-4.11). The propensity score matched analyses showed similar results. Conclusion: The uses of PPI and H2RA as a stress ulcer prophylaxis agent showed similarity in the incidence of nosocomial pneumonia and PMC.

• The Journal of Korean Society for Radiation Therapy
• /
• v.31 no.1
• /
• pp.25-32
• /
• 2019

Purpose: The size, shape, and volume of prosthetic appliance depend on the metal artifacts resulting from dental implant during head and neck treatment with radiation. This reduced the accuracy of contouring targets and surrounding normal tissues in radiation treatment plan. Therefore, the purpose of this study is to obtain the images of metal representing the size of tooth through MVCT, SMART-MAR CT and KVCT, evaluate the volumes, apply them into the proton therapy plan, and analyze the difference of dose distribution. Materials and Methods : Metal A ($0.5{\times}0.5{\times}0.5cm$), Metal B ($1{\times}1{\times}1cm$), and Metal C ($1{\times}2{\times}1cm$) similar in size to inlay, crown, and bridge taking the treatments used at the dentist's into account were made with Cerrobend ($9.64g/cm^3$). Metal was placed into the In House Head & Neck Phantom and by using CT Simulator (Discovery CT 590RT, GE, USA) the images of KVCT and SMART-MAR were obtained with slice thickness 1.25 mm. The images of MVCT were obtained in the same way with $RADIXACT^{(R)}$ Series (Accuracy $Precision^{(R)}$, USA). The images of metal obtained through MVCT, SMART-MAR CT, and KVCT were compared in both size of axis X, Y, and Z and volume based on the Autocontour Thresholds Raw Values from the computerized treatment planning equipment Pinnacle (Ver 9.10, Philips, Palo Alto, USA). The proton treatment plan (Ray station 5.1, RaySearch, USA) was set by fusing the contour of metal B ($1{\times}1{\times}1cm$) obtained from the above experiment by each CT into KVCT in order to compare the difference of dose distribution. Result: Referencing the actual sizes, it was appeared: Metal A (MVCT: 1.0 times, SMART-MAR CT: 1.84 times, and KVCT: 1.92 times), Metal B (MVCT: 1.02 times, SMART-MAR CT: 1.47 times, and KVCT: 1.82 times), and Metal C (MVCT: 1.0 times, SMART-MAR CT: 1.46 times, and KVCT: 1.66 times). MVCT was measured most similarly to the actual metal volume. As a result of measurement by applying the volume of metal B into proton treatment plan, the dose of $D_{99%}$ volume was measured as: MVCT: 3094 CcGE, SMART-MAR CT: 2902 CcGE, and KVCT: 2880 CcGE, against the reference 3082 CcGE Conclusion: Overall volume and axes X and Z were most identical to the actual sizes in MVCT and axis Y, which is in the superior-Inferior direction, was regular in length without differences in CT. The best dose distribution was shown in MVCT having similar size, shape, and volume of metal when treating head and neck protons. Thus it is thought that it would be very useful if the contour of prosthetic appliance using MVCT is applied into KVCT for proton treatment plan.

• The Journal of Korean Society for Radiation Therapy
• /
• v.19 no.2
• /
• pp.123-129
• /
• 2007

Purpose: CT scan shows that significant tumor movement occurs in lesions located in the proximity of the heart, diaphragm, and lung hilus. There are differences concerning three kinds of type to get images following the Scan type called Axial, Helical, Cine (4D-CT) mode, when the scanning by CT. To know how each protocol describe accurately, this paper is going to give you reappearance using the moving phantom. Materials and Methods: To reconstruct the movement of superior-inferior and anterior-posterior, the manufactured moving phantom and the motor following breathing were used. To distinguish movement from captured images by CT scanning, a localizer adhered to the marker on the motor. The moving phantom fixed the movement of superior-inferior upon 1.3 cm /1 min. The motor following breathing fixed the movement of anterior-posterior upon 0.2 cm /1 min. After fixing each movement, CT scanning was taken by following the CT protocols. The movement of A localizer and volume-reappearance analyzed by RTP machine. Results: Total volume of a marker was 88.2 $cm^3$ considering movement of superior-inferior. Total volume was 184.3 $cm^3$. Total volume according to each CT scan protocol were 135 $cm^3$ by axial mode, 164.9 $cm^3$ by helical mode, 181.7 $cm^3$ by cine (4D-CT) mode. The most closely describable protocol about moving reappearance was cine mode, the marker attached localizer as well. Conclusion: CT scan should reappear concerning a exact organ-description and target, when the moving organ is being scanned by three kinds of CT protocols. The cine (4D-CT) mode has the advantage of the most highly reconstructible ability of the three protocols in reappearance of the marker using a moving phantom. The marker on the phantom has always regular motion but breathing patients don't move like a phantom. Breathing education and devices setting patients were needed so that images reconstruct breathing as exactly as possible. Users should also consider that an amount of radiation to patients is being bombed.

• Radioisotope journal
• /
• v.21 no.3
• /
• pp.46-60
• /
• 2006

In recent years the progress of nuclear medicine advanced dramatically in imaging and targeted radionuclide therapy is able to open op exciting perspectives as standard diagnostic and therapeutic modalities, complementing conventional modalities. Positron emission tomography/computed tomography (PET/CT) technology with FDG has been developed clinically in less than 10 years as a routine standard in oncological imaging, including a number of other fluorinated radiopharmaceuticals being evaluated for their ability to complement FDG. However, the limitation of FDG-PET such as non-specific uptake and its short half-life is not compatible with the time necessary for optimal tumour targeting. Therefore, a development of innovative positron-emitting radionuclides with half-lives longer than 10 h is needed. For therapeutic applications, the injection of higher activities is required to reach efficient adsorbed doses in radioresistant solid tumours, while limiting the irradiation of vital organs. In this application, the longer half-life of radiolsotopes are more fit well for radionuclide therapy. To achieve this, researches have to be carried in a largor spectrum of radionuclides for diagnosis and therapy. In the context of rapidly growing nuclear medicine and strong demanding innovative radionuclides, a high-energy (100 MeV), high-intensity (-mA) accelerator with proton (PEFF at KAFRI). will be operating in 2011. The priorities of PEFP will include supporting the nuclear medicine research community by providing those radionuclides with current limited availability by means of a high-energy, high-intensity accelerator.