• Radiation Oncology Journal
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• v.31 no.1
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• pp.1-11
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• 2013

Purpose: Compared to conventional radiotherapy (RT), intensity-modulated radiotherapy (IMRT) significantly reduces the rate of treatment-induced late toxicities in head and neck cancer. However, a clear survival benefit of IMRT over conventional RT has not yet been shown. This study is among the first comparative study to compare the survival rates between conventional RT and helical tomotherapy in head and neck cancer. Materials and Methods: From January 2008 to November 2011, 37 patients received conventional RT and 30 patients received helical tomotherapy for management of head and neck cancer. We retrospectively compared the survival rates between patients treated with conventional RT and helical tomotherapy, and analyzed the prognostic factors for survival. Results: The 1- and 2-year locoregional recurrence-free survival rates were 61.2% and 58.1% for the conventional RT group, 89.3% and 80.3% for the helical tomotherapy group, respectively. The locoregional recurrence-free survival rates of the helical tomotherapy group were significantly higher than conventional RT group (p = 0.029). There were no significant differences in the overall and distant metastasis-free survival between the two groups. RT technique, tumor stage, and RT duration were significant prognostic factors for locoregional recurrence-free survival. Conclusion: This study showed the locoregional recurrence-free survival benefits of helical tomotherapy in the treatment of head and neck cancers.

• Biomedical Science Letters
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• v.27 no.4
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• pp.283-290
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• 2021

Severe acute respiratory syndrome coronavirus (SARS-CoV2) is a major coronavirus that infects humans with human Coronavirus (HuCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle east respiratory syndrome coronavirus (MERS-CoV). SARS-CoV2 is currently a global pandemic pathogen. In this study, we developed conventional RT-PCR based diagnostic system for the detection of SARS-CoV2 which is relatively inexpensive but has high stability and a wide range of users. Three conventional RT-PCR primer sets capable of forming specific band sizes by targeting the ORF1ab [232 nucleotide (nt)], E (200 nt) and N (288 nt) genes of SARS-CoV2 were developed, respectively, and it were confirmed to be about 10~100 times higher detection sensitivity than the previously reported methods. In addition, a standard positive control that can generate specific amplicons by reacting with the developed RT-PCR primers and verify the false-positiv from contamination of the laboratory was produced. Therefore, the diagnostic system that uses the RT-PCR method is expected to be used to detect SARS-CoV2.

• The Plant Pathology Journal
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• v.27 no.4
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• pp.385-389
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• 2011

A new reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the Potato leafroll virus (PLRV) was developed and compared with conventional reverse transcription polymerase chain reaction (RT-PCR) to address its advantages over RTPCR. RT-LAMP primers were designed from the open reading frame 3 (ORF3) sequence of PLRV. The RT-LAMP reactions were conducted without or with a set of loop primers. By real-time monitoring using Turbimeter, the RT-LAMP (with loop primers) detects PLRV in less than 30 min, compared to 120 min of RT-PCR. By adding fluorescent reagent during the reaction, final products of the RT-LAMP were fluorescently visualized under UV light or could be differentiated by naked-eye inspection under normal light. The RT-LAMP was extremely sensitive, about 2000-fold more sensitive than RT-PCR. This study presents great potential of the RT-LAMP for diagnosis and PLRV epidemiology because RT-LAMP method is speedy, sensitive, inexpensive, and convenient.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1165-1169
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• 2012

In April 2009, the H1N1 pandemic influenza virus emerged as a novel influenza virus. The aim of this study was to compare the performances of several molecular assays, including conventional reverse transcription polymerase chain reaction (RT-PCR), two real-time reverse transcription (rRT)-PCRs, and two multiplex RTPCRs. A total of 381 clinical specimens were collected from patients (223 men and 158 women), and both the Seeplex RV7 assay and rRT-PCR were ordered on different specimens within one week after collection. The concordance rate for the two methods was 87% (332/381), and the discrepancy rate was 13% (49/381). The positive rates for the molecular assays studied included 93.1% for the multiplex Seeplex RV7 assay, 93.1% for conventional reverse transcription (cRT)-PCR, 89.7% for the multiplex Seeplex Flu ACE Subtyping assay, 82.8% for protocol B rRT-PCR, and 58.6% for protocol A rRT-PCR. Our results showed that the multiplex Seeplex assays and the cRT-PCR yielded higher detection rates than rRT-PCRs for detecting the influenza A (H1N1) virus. Although the multiplex Seeplex assays had the advantage of simultaneous detection of several viruses, they were time-consuming and troublesome. Our results show that, although rRT-PCR had the advantage, the detection rates of the molecular assays varied depending upon the source of the influenza A (H1N1)v virus. Our findings also suggest that rRT-PCR sometimes detected virus in extremely low abundance and thus required validation of analytical performance and clinical correlation.

• Genomics & Informatics
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• v.18 no.4
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• pp.40.1-40.8
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• 2020

Avian influenza (AIV) outbreaks can induce fatal human pulmonary infections in addition to economic losses to the poultry industry. In this study, we aimed to develop a rapid and sensitive point-of-care AIV test using loop-mediated isothermal amplification (LAMP) technology. We designed three sets of reverse transcription LAMP (RT-LAMP) primers targeting the matrix (M) and hemagglutinin (HA) genes of the H5 and H9 subtypes. RT-LAMP targeting the universal M gene was designed to screen for the presence of AIV and RT-LAMP assays targeting H5-HA and H9-HA were designed to discriminate between the H5 and H9 subtypes. All three RT-LAMP assays showed specific amplification results without nonspecific reactions. In terms of sensitivity, the detection limits of our RT-LAMP assays were 100 to 1,000 RNA copies per reaction, which were 10 times more sensitive than the detection limits of the reference reverse-transcription polymerase chain reaction (RT-PCR) (1,000 to 10,000 RNA copies per reaction). The reaction time of our RT-LAMP assays was less than 30 min, which was approximately four times quicker than that of conventional RT-PCR. Altogether, these assays successfully detected the existence of AIV and discriminated between the H5 or H9 subtypes with higher sensitivity and less time than the conventional RT-PCR assay.

• The Plant Pathology Journal
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• v.38 no.6
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• pp.665-672
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• 2022

Cymbidium mosaic virus (CymMV) is one of economically important viruses that cause significant losses of orchids in the world. In the present study, a reverse transcription recombinase polymerase amplification (RT-RPA) assay combined with a lateral flow immunostrip (LFI) assay was developed for the detection of CymMV in orchid plants. A pair of primers containing fluorescent probes at each terminus that amplifies highly specifically a part of the coat protein gene of CymMV was determined for RT-RPA assay. The RT-RPA assay involved incubation at an isothermal temperature (39℃) and could be performed rapidly within 30 min. In addition, no cross-reactivity was observed to occur with odontoglossum ringspot virus and cymbidium chlorotic mosaic virus. The RT-RPA with LFI assay (RT-RPA-LFI) for CymMV showed 100 times more sensitivity than conventional reverse transcription polymerase chain reaction (RT-PCR). Furthermore, the RT-PCR-LFI assay demonstrated the simplicity and the rapidity of CymMV detection since the assay did not require any equipment, by comparing results with those of conventional RT-PCR. On-site application of the RT-RPA-LFI assay was validated for the detection of CymMV in field-collected orchids, indicating a simple, rapid, sensitive, and reliable method for detecting CymMV in orchids.

• Progress in Medical Physics
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• v.33 no.4
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• pp.121-128
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• 2022

Purpose: This study evaluated the quality of plans based on magnetic resonance-guided radiotherapy (MRgRT) tri-Co-60, linac, and conventional linac-based volumetric modulated arc therapy (linac-VMAT) for prostate cancer. Methods: Twenty patients suffering from prostate cancer with intermediate risk who were treated by MAT were selected. Additional treatment plans (primary and boost plans) were generated based on MRgRT-tri-Co-60 and MRgRT-linac. The planning target volume (PTV) of MRgRT-based plans was created by adding a 3 mm margin from the clinical target volume (CTV) due to high soft-tissue contrast and real-time motion imaging. On the other hand, the PTV of conventional linac was generated based on a 1 cm margin from CTV. The targets of primary and boost plans were prostate plus seminal vesicle and prostate only, respectively. All plans were normalized to cover 95% of the target volume by 100% of the prescribed dose. Dosimetric characteristics were evaluated for each of the primary, boost, and sum plans. Results: For target coverage and conformity, the three plans showed similar results. In the sum plans, the average value of V_65Gy of the rectum of MRgRT-linac (2.62%±2.21%) was smaller than those of MRgRT tri-Co-60 (9.04%±3.01%) and linac-VMAT (9.73%±7.14%) (P<0.001). In the case of bladder, the average value of V_65Gy of MRgRT-linac was also smaller. Conclusions: In terms of organs at risk sparing, MRgRT-linac shows the best value while maintaining comparable target coverage among the three plans.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.9-14
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• 2013

Purpose: High-energy radiotherapy with 10 MV or higher develops photoneutron through photonuclear reaction. Photoneutron has higher radiation weighting factor than X-ray, thus low dose can greatly affect the human body. An accurate dosimetric calculation and consultation are needed. This study compared and analyzed the dose change of photoneutron in terms of space according to the size of photon beam energy and treatment methods. Materials and Methods: To measure the dose change of photoneutron by the size of photon beam energy, patients with the same therapy area were recruited and conventional plans with 10 MV and 15 MV were each made. To measure the difference between the two treatment methods, 10 MV conventional plan and 10 MV IMRT plan was made. A detector was placed at the point which was 100 cm away from the photon beam isocenter, which was placed in the center of $^3He$ proportional counter, and the photoneutron dose was measured. $^3He$ proportional counter was placed 50 cm longitudinally superior to and inferior to the couch with the central point as the standard to measure the dose change by position changes. A commercial program was used for dose change analysis. Results: The average integral dose by energy size was $220.27{\mu}Sv$ and $526.61{\mu}Sv$ in 10 MV and 15 MV conventional RT, respectively. The average dose increased 2.39 times in 15 MV conventional RT. The average photoneutron integral dose in conventional RT and IMRT with the same energy was $220.27{\mu}Sv$ and $308.27{\mu}Sv$ each; the dose in IMRT increased 1.40 times. The average photoneutron integral dose by measurement location resulted significantly higher in point 2 than 3 in conventional RT, 7.1% higher in 10 MV, and 3.0% higher in 15 MV. Conclusion: When high energy radiotherapy, it should consider energy selection, treatment method and patient position to reduce unnecessary dose by photoneutron. Also, the dose data of photoneutron needs to be systematized to find methods to apply computerization programs. This is considered to decrease secondary cancer probabilities and side effects due to radiation therapy and to minimize unnecessary dose for the patients.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.157-165
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• 2004

Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO(Time-triggered Message-triggered Object)structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems. Start after striking space key 2 times.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.6
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• pp.863-872
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• 2002

Real-time(RT) object-oriented(00) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO(Time-triggered Message-triggered Object) structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established 00 programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems.