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PURPOSE: Lung Cancer Subcommittee of Korean Radiation Oncology Group (KROG) has recently launched a prospective clinical trial (KROG 17-06) of hippocampus-sparing whole brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) in treating multiple brain metastases from non-small cell lung cancer. In order to improve trial quality, dummy run studies among the participating institutions were designed. This work reported the results of two-step dummy run procedures of the KROG 17-06 study. MATERIALS AND METHODS: Two steps tested hippocampus contouring variability and radiation therapy planning compliance. In the first step, the variation of the hippocampus delineation was investigated for two representative cases using the Dice similarity coefficients. In the second step, the participating institutions were requested to generate a HS-WBRT with SIB treatment plan for another representative case. The compliance of the treatment plans to the planning protocol was evaluated. RESULTS: In the first step, the median Dice similarity coefficients of the hippocampus contours for two other dummy run cases changed from 0.669 (range, 0.073 to 0.712) to 0.690 (range, 0.522 to 0.750) and from 0.291 (range, 0.219 to 0.522) to 0.412 (range, 0.264 to 0.598) after providing the hippocampus contouring feedback. In the second step, with providing additional plan priority and extended dose constraints to the target volumes and normal structures, we observed the improved compliance of the treatment plans to the planning protocol. CONCLUSION: The dummy run studies demonstrated the notable inter-institutional variability in delineating the hippocampus and treatment plan generation, which could be decreased through feedback from the trial center.
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Brain , Carcinoma, Non-Small-Cell Lung , Compliance , Hippocampus , Lung Neoplasms , Neoplasm Metastasis , Prospective Studies , Radiation Oncology , RadiotherapyABSTRACT
This study presents an electronic portal imaging devices (EPIDs) based on daily check tool for Linac that is usable for different cancer centers.Several images of open rectangle fields were acquired with EPID and the key items of daily Linac check were derived from the obtained images using an in-house developed automatic analysis software.The experiment results showed that each parameter calculated by this tool is as reliable as the corresponding result measured by the commercial quality assurance devices and its measuring efficiency is much higher.
Subject(s)
Electronics, Medical , Electrons , Particle Accelerators , Phantoms, Imaging , Radiometry , SoftwareABSTRACT
Objective To explore the effects of Qa-1 and PD-L1 loaded artificial liposomal treatment in allograft rejection and its outcomes .Methods The extracellular domains of Qa-1 and PD-L1 were loaded on liposome surface by streptavidin-biotin system . Mixed lymphocyte reaction (MLR) was performed for measuring Qa-1/PD-L1 liposome biological function .Then liposome was co-transplanted with allo-islets via portal vein .The levels of blood glucose and C-peptide were detected daily after transplantation .Also hepatic lymphocytes after transplantation were isolated for determining the proportion of activated cells and signaling pathway changes .Results Artificial liposome could be easily loaded with biotinylated peptide and its diameter was between 50 to 500 nm . Qa-1/PD-L1 liposome could significantly suppress lymphocyte proliferation , activation and secretion of IFN-γ in MLR by an activation of SHP1/2 and an inhibition of Syk pathway .Qa-1/ PD-L1 liposomes could suppress the activation of hepatic lymphocytes in vivo by activating SHP1/2 ,protecting islet allografts and maintaining a normal level of blood glucose in recipients .Conclusions Qa-1/PD-L1 loaded liposome can effectively suppress allograft rejection and improve the outcomes of islet transplantation .
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MRI simulator(MRI-Sim) images have unique clinical advantages with higher resolution of soft tissue and clearer visualization of tissue boundaries. Thus, the precise positioning of the tumor target area can be achieved and it is widely used in the field of radiotherapy. This article focuses on the acceptance test project and image quality assurance work of MRI-Sim equipment. The obtained ACR phantom images were used to analyze various image quality assurance indicators, and the results all reached the set standards, thereby ensuring that the obtained images meet the requirements of clinical applications.
Subject(s)
Magnetic Resonance Imaging , Phantoms, Imaging , Quality Assurance, Health CareABSTRACT
Objective To investigate the effect of doxycycline on the Th1/Th2 cell balance in experimental allergic encepha-lomyelitis(EAE)rats.Methods Forty female Wistar rats were randomly divided into the EAE control group,low,medium and high does DOX treatment groups,10 cases in each group.The onset situation in rats was observed.The IL-4 and IFN-γlevels secreted by peripheral blood mononuclear cells (PBMC)at the peak stage were detected.The levels of IL-1β,IL-10,TNF-αin brain tissue,and the albumin content in cerebrospinal fluid and serum were detected.The QA value was calculated.Results In each DOX group,the clinical symptoms of rats were alleviated compared with the EAE control group.In each DOX group,the PBMC secreting IFN-γlev-el and IFN-γ/IL-4 ratio in the onset peak stage were lower than those in the EAE control group,while the IL-4 level was higher than that in the EAE control group(P 0.05),but the difference between other DOX groups had statistical significance(P <0.01).The IL-1βand TNF-αlevels of brain tissue and QA value during onset peak stage in various doses DOX groups were decreased compared with the EAE control group,while the IL-10 level was increased compared with the EAE control group(P <0.05).With the DOX dose increasing,the levels of IL-1β,TNF-αand QA value in various doses DOX groups became lower,the IL-10 level became high-er,there was statistically significant difference among various doses DOX groups (P <0.05 ).Conclusion DOX can obviously alle-viate the clinical symptoms of EAE rats,its mechanism may be related with that DOX could decrease the level of Th1 cytokine and increase the level of Th2 cytokine,correct the Th1/Th2 cell balance,thus protect the blood brain barrier(BBB).
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The paper analyzes the documents related to the foreign medical automatic Question Answering (QA) system,and compares the differences between automatic QA and traditional network information retrieval,describes the automatic QA system in the aspects of application researches,common tools and relevant technologies.Combining foreign related researches,it also discusses the current key problems of medical automatic QA system and the implications for China in order to offer reference for further research.
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In view of the characteristics of the computerized system,the key points in the quality assurance (QA) of the computerized system was discussed and summarized combined with the requirements of the GLP laboratory in Europe and America.The validation of computerized system,the control during the use of computerized system,period maintenance and safety protection of computerized system,archives of electronic data was discussed,expecting to provide reference for the management of computerized system in Chinese GLP laboratory which is generally not high currently.The experiences were obtained as follow:Through repeated inspection and review,the problem was found and set as the risk point;a targeted QA inspection plan was made focusing on the risk-based inspection and the QA inspection plan was timely adjusted according to the problems,which ensures the pertinence and validity of the QA inspection.
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The paper firstly introduces the research status of autism and analyzes the gap between China and the US in autism net-work service, proposes using the mainstream socialized Q&A community data in foreign countries to construct an autism Q&A knowledge base.It introduces data collection, management, service process and key issues of the knowledge base and gives application examples of the knowledge services.Construction of this knowledge base can provide targeted and valuable knowledge services to users and can help enhance the retrieval efficiency.
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The evolutionary conserved, less‑polymorphic, nonclassical major histocompatibility complex (MHC) class I molecules: Qa‑1 and its human homologue human leukocyte antigen‑E (HLA‑E) along with HLA‑F, G and H cross‑talk with the T‑cell receptors and also interact with natural killer T‑cells and other lymphocytes. Moreover, these nonclassical MHC molecules are known to interact with CD94/NKG2 heterodimeric receptors to induce immune responses and immune regulations. This dual role of Qa‑1/ HLA‑E in terms of innate and adaptive immunity makes them more interesting. This review highlights the new updates of the mammalian nonclassical MHC‑I molecules in terms of their gene organization, evolutionary perspective and their role in immunity.
Subject(s)
Biological Evolution/genetics , /genetics , /immunology , Humans , Immunity/genetics , Immunity/immunology , Mammals/genetics , Mammals/immunologyABSTRACT
Understanding germinal center reactions is crucial not only for the design of effective vaccines against infectious agents and malignant cells but also for the development of therapeutic intervention for the treatment of antibody-mediated immune disorders. Recent advances in this field have revealed specialized subsets of T cells necessary for the control of B cell responses in the follicle. These cells include follicular regulatory T cells and Qa-1-restricted cluster of differentiation (CD)8+ regulatory T cells. In this review, we discuss the current knowledge related to the role of regulatory T cells in the B cell follicle.
Subject(s)
Germinal Center , Immune System Diseases , T-Lymphocytes , T-Lymphocytes, Helper-Inducer , T-Lymphocytes, Regulatory , VaccinesABSTRACT
Objective To compare IMSure QA and MatriXX for intensity modulated radiotherapy plans,and to investigate the credibility of IMSure QA software.Methods Ten patients receiving intensity modulated radiotherapy were randomly chosen for the quality assurance plans with IMSure QA and MatriXX.Results The overall average of percentage pass points in 3％ and 3 mm were (98.1 ± 0.8) ％ with IMSure QA,and (97.9 ±0.6)％ with MatriXX(t =0.86,P ＞0.05).Conclusion IMSure QA can be a reliable verification tool for IMRT QA.
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Objective To evaluate the sensitivity of patient-specific volumetric-modulated arc therapy (VMAT) quality assurance (QA) to minor multileaf collimator (M LC) positioning errors.Methods Systematic multileaf collimator (MLC) positioning errors (+0.5 mm,+ 1 mm and +2 mm) were introduced into the clinical VMAT patient plans with 2 types of MLC positioning errors:systematic MLC gap width errors and systematic MLC shift errors for 6 cases,including 3 cases with prostatic cancer and 3 cases with nasopharyngeal cancer.The planar dose distributions of the original and modified plans were measured using ArcCheck array.The coincidence between the measured results and the calculated results was evaluated using both absolute distance-to-agreement (AD-DTA) analysis with 3％/3 mm and 2％/2 mm criteria.Results The average passing rate of the 6 original VMAT plans was 96.0％ with the ADDTA criteria of 3％/3 mm which was commonly adopted in clinical practice.For the MLC gap width errors of + 1 mm,+2 mm,and-2 mm and the MLC shift errors of 2 mm,the drop levels in average passing rate with the AD-DTA criteria of 3％/3 mm were 8.8％,15.5％,6.1％ and 7.9％,respectively.The + 2 mm MLC positioning errors and + 1 mm MLC gap width errors could be detected by the patient-specific VMAT QA procedure.The AD-DTA criteria of 2％/2 mm was more sensitive compared with the criteria of 3％/3 mm.Conclusions Patient-specific VMAT QA is not sensitive enough to detect the systematic MLC positioning errors within 1 mm.Additional MLC QA is needed to guarantee the accuracy of VMAT delivery.
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The aim of this study is to evaluate plan quality and dose accuracy for Volumetric Modulated Arc Therapy (VMAT) on the TG-119 and is to investigate the effects on variation of the selectable optimization parameters of VMAT. VMAT treatment planning was implemented on a Varian iX linear accelerator with ARIA record and verify system (Varian Mecical System Palo Alto, CA) and Oncentra MasterPlan treatment planning system (Nucletron BV, Veenendaal, Netherlands). Plan quality and dosimetric accuracy were evaluated by effect of varying a number of arc, gantry spacing and delivery time for the test geometries provided in TG-119. Plan quality for the target and OAR was evaluated by the mean value and the standard deviation of the Dose Volume Histograms (DVHs). The ionization chamber and Delta4PT bi-planar diode array were used for the dose evaluation. For treatment planning evaluation, all structure sets closed to the goals in the case of single arc, except for the C-shape (hard), and all structure sets achieved the goals in the case of dual arc, except for C-shape (hard). For the variation of a number of arc, the simple structure such as a prostate did not have the difference between single arc and dual arc, whereas the complex structure such as a head and neck showed a superior result in the case of dual arc. The dose distribution with gantry spacing of 4degrees was shown better plan quality than the gantry spacing of 6degrees, but was similar results compared with gantry spacing of 2degrees. For the verification of dose accuracy with single arc and dual arc, the mean value of a relative error between measured and calculated value were within 3% and 4% for point dose and confidence limit values, respectively. For the verification on dose accuracy with the gantry intervals of 2degrees, 4degrees and 6degrees, the mean values of relative error were within 3% and 5% for point dose and confidence limit values, respectively. In the verification of dose distribution with Delta4PT bi-planar diode array, gamma passing rate was 98.72+/-1.52% and 98.3+/-1.5% for single arc and dual arc, respectively. The confidence limit values were within 4%. The smaller the gantry spacing, the more accuracy results were shown. In this study, we performed the VMAT QA based on TG-119 procedure, and demonstrated that all structure sets were satisfied with acceptance criteria. And also, the results for the selective optimization variables informed the importance of selection for the suitable variables according to the clinical cases.
Subject(s)
Head , Neck , Particle Accelerators , Prostate , Radiotherapy, Intensity-ModulatedABSTRACT
For applying the quality assurance (QA) of volumetric modulated arc therapy (VMAT) introduced in Eulji Hospital, we classify it into three different QA steps, treatment planning QA, pretreatment delivering QA, and treatment verifying QA. These steps are based on the existing intensity modulated radiation therapy (IMRT) QA that is currently used in our hospital. In each QA step, the evaluated items that are from QA program are configured and documented. In this study, QA program is not only applied to actual patient treatment, but also evaluated to establish a reference of clinical acceptance in pretreatment delivering QA. As a result, the confidence limits (CLs) in the measurements for the high-dose and low-dose regions are similar to the conventional IMRT level, and the clinical acceptance references in our hospital are determined to be 3 to 5% for the high-dose and the low-dose regions, respectively. Due to the characteristics of VMAT, evaluation of the intensity map was carried out using an ArcCheck device that was able to measure the intensity map in all directions, 360degrees. With a couple of dosimetric devices, the gamma index was evaluated and analyzed. The results were similar to the result of individual intensity maps in IMRT. Mapcheck, which is a 2-dimensional (2D) array device, was used to display the isodose distributions and gave very excellent local CL results. Thus, in our hospital, the acceptance references used in practical clinical application for the intensity maps of 360degrees directions and the coronal isodose distributions were determined to be 93% and 95%, respectively. To reduce arbitrary uncertainties and system errors, we had to evaluate the local CLs by using a phantom and to cooperate with multiple organizations to participate in this evaluation. In addition, we had to evaluate the local CLs by dividing them into different sections about the patient treatment points in practical clinics.
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Humans , Radiotherapy, Intensity-ModulatedABSTRACT
OBJECTIVE: The purpose of this study was to evaluate any improvement in the quality of abdominal CTs after the utilization of the nationally based accreditation program. MATERIALS AND METHODS: Approval was obtained from the Institutional Review Board, and informed consent was waived. We retrospectively analyzed 1,011 outside abdominal CTs, from 2003 to 2007. We evaluated images using a fill-up sheet form of the national accreditation program, and subjectively by grading for the overall CT image quality. CT scans were divided into two categories according to time periods; before and after the implementation of the accreditation program. We compared CT scans between two periods according to parameters pertaining to the evaluation of images. We determined whether there was a correlation between the results of a subjective assessment of the image quality and the evaluation scores of the clinical image. RESULTS: The following parameters were significantly different after the implementation of the accreditation program: identifying data, display parameters, scan length, spatial and contrast resolution, window width and level, optimal contrast enhancement, slice thickness, and total score. The remaining parameters were not significantly different between scans obtained from the two different periods: scan parameters, film quality, and artifacts. CONCLUSION: After performing the CT accreditation program, the quality of the outside abdominal CTs show marked improvement, especially for the parameters related to the scanning protocol.
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Humans , Accreditation , Quality Improvement , Radiography, Abdominal/standards , Republic of Korea , Retrospective Studies , Tomography, X-Ray Computed/standardsABSTRACT
Radiation treatment for skin cancer has recently increased in tomotherapy. It was reported that required dose could be delivered with homogeneous dose distribution to the target without field matching using electron and photon beam. Therapeutic beam of tomotherapy, however, has several different physical characteristic and irradiation of helical beam is involved in the mechanically dynamic factors. Thus verification of skin dose is requisite using independent tools with additional verification method. Modified phantom for dose measurement was developed and skin dose verification was performed using inserted thermoluminescent dosimeters (TLDs) and GafChromic EBT films. As the homogeneous dose was delivered to the region including surface and 6 mm depth, measured dose using films showed about average 2% lower dose than calculated one in treatment planning system. Region indicating about 14% higher and lower absorbed dose was verified on measured dose distribution. Uniformity of dose distribution on films decreased as compared with that of calculated results. Dose variation affected by inhomogeneous material, Teflon, little showed. In regard to the measured dose and its distribution in tomotherapy, verification of skin dose through measurement is required before the radiation treatment for the target located at the curved surface or superficial depth.
Subject(s)
Electrons , Polytetrafluoroethylene , Radiotherapy, Intensity-Modulated , Skin , Skin NeoplasmsABSTRACT
Two trials of external quality assessment were performed in 2008. The first and the second trials assessed by three test categories, i.e., tumor markers, thyroid hormones and immunoproteins (IgG, IgM, IgA, C3 and C4). Fifteen test items using immunoassay method were surveyed as scheduled. The number of participated laboratory of external quality assessment for Immunoassay Subcommittee were 437 institutions in the first trial survey and 476 institutions in the second survey.Fourteen control materials consisted of 12 home-made pooled sera and 2 commercial control sera (Liquimmune(R), Liquid Assayed Immunoassay Control, Microgenics Co, USA) were used. The results are summarized as follows. 1. Laboratories participating in external quality control program of immunoassay were 437 and 476 laboratories and the response rate were 94.6% and 98.7% in 2008. 2. Chemiluminiscence immunoassay autoanalyzers were most commonly used for immunoassay testing in the clinical laboratories for detecting tumor markers and hormones. 3. Some analyzers of a few test items showed variations of the test results of the same control material probably due to personal factors of the institution. 4. Workshops titled "Quality control of Immunoassay" and " Quality control of tumor markers" were held on September 5, 2008 and December 3, 2008 in cooperation with Annual Autumn Academic Conferences of Clinical laboratory and Quality Control and Immunoserology Subcommittee. The quality of the participating laboratories seems to be thought being continuously improved. And, this year, about 51 laboratories are newly participated to our Immunoassay Subcommittee.
Subject(s)
Humans , Congresses as Topic , Immunoassay , Immunoglobulin A , Immunoglobulin M , Immunoproteins , Quality Control , Thyroid Hormones , Biomarkers, TumorABSTRACT
PURPOSE: To compare the accuracy and efficacy of EDR2 film, a 2D ionization chamber array (MatriXX) and an amorphous silicon electronic portal imaging device (EPID) in the pre-treatment QA of IMRT. MATERIALS AND METHODS: Fluence patterns, shaped as a wedge with 10 steps (segments) by a multi-leaf collimator (MLC), of reference and test IMRT fields were measured using EDR2 film, the MatriXX, and EPID. Test fields were designed to simulate leaf positioning errors. The absolute dose at a point in each step of the reference fields was measured in a water phantom with an ionization chamber and was compared to the dose obtained with the use of EDR2 film, the MatriXX and EPID. For qualitative analysis, all measured fluence patterns of both reference and test fields were compared with calculated dose maps from a radiation treatment planning system (Pinnacle, Philips, USA) using profiles and gamma evaluation with 3%/3 mm and 2%/2 mm criteria. By measurement of the time to perform QA, we compared the workload of EDR2 film, the MatriXX and EPID. RESULTS: The percent absolute dose difference between the measured and ionization chamber dose was within 1% for the EPID, 2% for the MatriXX and 3% for EDR2 film. The percentage of pixels with gamma%>1 for the 3%/3 mm and 2%/2 mm criteria was within 2% for use of both EDR2 film and the EPID. However, differences for the use of the MatriXX were seen with a maximum difference as great as 5.94% with the 2%/2 mm criteria. For the test fields, EDR2 film and EPID could detect leaf-positioning errors on the order of -3 mm and -2 mm, respectively. However it was difficult to differentiate leaf-positioning errors with the MatriXX due to its poor resolution. The approximate time to perform QA was 110 minutes for the use of EDR2 film, 80 minutes for the use of the MatriXX and approximately 55 minutes for the use of the EPID. CONCLUSION: This study has evaluated the accuracy and efficacy of EDR2 film, the MatriXX and EPID in the pre-treatment verification of IMRT. EDR2 film and the EPID showed better performance for accuracy, while the use of the MatriXX significantly reduced measurement and analysis times. We propose practical and useful methods to establish an effective QA system in a clinical environment.
Subject(s)
Electronics , Electrons , Silicon , WaterABSTRACT
In this study, we developed the protopype of QA phantom for image QA including an additional component for image based radiation treatment system. The new phantom considered two main parts: Image quality and fusion accuracy. Image quality part included for daily CT number linearity and spatial resolution, and fusion accuracy part designed to simulate a simple translation-rotation setting. The CT scans of the phantom obtained from conventional CT, MVCT of Tomotherapy unit, and both image sets were satisfied the recommendation of spatial resolution. This phantom was simple and efficient for daily imaging QA, and it is important to provide a new concept of verification of image registration.
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PURPOSE: Film dosimetry as a part of patient specific intensity modulated radiation therapy quality assurance (IMRT QA) was performed to develop a new optimization method of film isocenter offset and to then suggest new quantitative criteria for film dosimetry. MATERIALS AND METHODS: Film dosimetry was performed on 14 IMRT patients with head and neck cancers. An optimization method for obtaining the local minimum was developed to adjust for the error in the film isocenter offset, which is the largest part of the systemic errors. RESULTS: The adjust value of the film isocenter offset under optimization was 1 mm in 12 patients, while only two patients showed 2 mm translation. The means of absolute average dose difference before and after optimization were 2.36 and 1.56%, respectively, and the mean ratios over a 5% tolerance were 9.67 and 2.88%. After optimization, the differences in the dose decreased dramatically. A low dose range cutoff (L-Cutoff) has been suggested for clinical application. New quantitative criteria of a ratio of over a 5%, but less than 10% tolerance, and for an absolute average dose difference less than 3% have been suggested for the verification of film dosimetry. CONCLUSION: The new optimization method was effective in adjusting for the film dosimetry error, and the newly quantitative criteria suggested in this research are believed to be sufficiently accurate and clinically useful.