ABSTRACT
Objective:To establish and evaluate a new real-time quality control method that can identify the random errors by using the backpropagation neural network (BPNN) algorithm and taking blood glucose test as an example.Methods:A total of 219 000 blood glucose results measured by Siemens advia 2 400 analytical system from January 2019 to July 2020 and derived from Laboratory Information System of Beijing Chaoyang Hospital Laboratory Department was regarded as the unbiased data of our study. Six deviations with different sizes were introduced to generate the corresponding biased data. With each biased data, BPNN and MovSD algorithms were used and tested, and then evaluated by traceability method and clinical method.Results:For BPNN algorithm, the block size was pre-set to 10 and the false-positive rate in all biases was within 0.1%. For MovSD, however, the optimal block size and exclusive limit were 150 and 10% separately and its false-positive rate in all biases was 0.38%, which was 0.28% higher than BPNN. Especially, for the least two error factors of 0.5 and 1, all the random errors were not detected by MovSD; for the error factor larger than 1, random errors could be detected by MovSD but the MNPed was higher than that of BPNN under all deviations. The difference was up to 91.67 times. 460 000 reference data were produced by traceability procedure. The uncertainty of BPNN algorithm evaluated by these reference data was only 0.078%.Conclusion:A real-time quality control method based on BPNN algorithm was successfully established to identify random errors in analytical phase, which was more efficient than MovSD method and provided a new idea and method for the identification of random errors in clinical practice.
ABSTRACT
Objective:To evaluate the dosimetric effect of multi-leaf collimator (MLC) position error on dynamic intensity-modulated radiotherapy (dMLC-IMRT), aiming to provide guidance for the establishment of MLC quality control accuracy and operation tolerance.Methods:In the phantom study, the virtual water phantom established in the treatment planning system (TPS), and three dynamic sliding window test fields with gap width of 5 mm, 10 mm and 20 mm were designed. Clinical treatment plans of 7 common tumor types were extracted, including nasopharyngeal carcinoma, glioma, lung cancer, esophageal cancer, cervical cancer, prostate cancer, and breast cancer, with 6 cases in each. MLC errors were introduced into the copy from original plan to generate the simulation plans. MLC errors included systematic open/close error, systematic deviation error and random error. The dosimetric differences between the original and simulation plans were compared.Results:The phantom study showed that the symbol of dose deviation was the same as that of systematic open/close error, and the value was increased with the increase of MLC error and decreased with the increase of gap width. The results of patient study showed that the systematic open/close error had a significant effect on dosimetry, the target volume dose sensitivities of different plans were 7.258-13.743%/mm, and were negatively correlated with the average field width. The dosimetric deviation caused by the systematic shift error below 2 mm was less than 2%. The dosimetric change caused by the random error below 2 mm could be neglected in clinical treatment.Conclusions:The minimal gap width should be limited in TPS, whereas the quality control of MLC should be strengthened. In addition, for the dynamic intensity-modulated treatment technology, 2 mm random error was suggested to be the operation tolerance during treatment delivery, and 0.2 mm alignment accuracy on each side (or 0.4 mm unilateral) is recommended to be the MLC quality control accuracy to ensure the dose accuracy of radiotherapy for different tumors.
ABSTRACT
Introduction: The aim of the present study was to compare two immobilization systems for comparison of setup errors in targeted radiotherapy. Methods: Retrospective analysis was done for the patients undergoing radiotherapy from May 2012 to December 2018 at our institution. Immobilization was performed on 30 patients sessions (Vacuum cushion i.e., Vac-Lok™ = 15; Thermoplastic mould i.e., Pelvicast pelvic masks = 15). A total of 763 cone-beams were analysed. The target lesion location was verified by cone-beam computed tomography (CBCT) prior to each session, with displacements assessed by CBCT simulation prior to each treatment session. Systematic setup errors, random setup errors, isocenter deviations in the Medio-lateral (ML), Supero-inferior (SI), Antero-posterior (AP), Rotation (yaw) directions of the patient position was calculated. Results: On comparing the Vac-Lok™ and Pelvicast pelvic masks group with respect to Systematic and random error in the lateral, longitudinal, vertical and YAW direction, no statistically significant difference was seen except the random error in YAW direction (P=0.037, Unpaired t-test). There was no difference observed in comparing the isocentric deviation. Conclusion: It was inferred and concluded that using a vacuum cushion for pelvic radiotherapy provides no added benefit compared to using a thermoplastic mould. Thermoplastic mould is recommended for patients receiving pelvic radiotherapy to improve overall reproducibility
ABSTRACT
As an extension of proteomics, peptidomics has been widely used in medical and biological researches. However, the effect of reproducibility of identification method on peptidomics is not yet clear. In this work, the urine sample of a healthy people was analyzed for seven times in parallel by nano-liquid chromatography-high-resolution tandem mass spectrometry. To illustrate the variability and stability among these experiments, the number of spectra, the utilization of total spectra, the number of identified peptides, the number of proteins, and the ionic strength and retention time of peptides were counted and compared. The average number of peptides was 208 and the standard deviation was 38. 7. After all of data were combined, 426 peptides belonging to 114 proteins were obtained, while only 109 peptides coming from 35 proteins were identified in each experiment, indicating that there were both an randomness and a relative stability for LC-MS analysis. Increasing the number of parallel experiments would expand the data set of peptidomics, but the rate of increase would decrease over 3 or more measurements. Compared with peptides, the results of peptidomics were more stable at protein level, indicating that proteins were more robustly peptidomics biomarker than the peptides.
ABSTRACT
As an extension of proteomics, peptidomics has been widely used in medical and biological researches. However, the effect of reproducibility of identification method on peptidomics is not yet clear. In this work, the urine sample of a healthy people was analyzed for seven times in parallel by nano-liquid chromatography-high-resolution tandem mass spectrometry. To illustrate the variability and stability among these experiments, the number of spectra, the utilization of total spectra, the number of identified peptides, the number of proteins, and the ionic strength and retention time of peptides were counted and compared. The average number of peptides was 208 and the standard deviation was 38. 7. After all of data were combined, 426 peptides belonging to 114 proteins were obtained, while only 109 peptides coming from 35 proteins were identified in each experiment, indicating that there were both an randomness and a relative stability for LC-MS analysis. Increasing the number of parallel experiments would expand the data set of peptidomics, but the rate of increase would decrease over 3 or more measurements. Compared with peptides, the results of peptidomics were more stable at protein level, indicating that proteins were more robustly peptidomics biomarker than the peptides.
ABSTRACT
The purpose of this article is to explore the quality assurance methods in carrying out laboratory investigations on various kits and biological products and analysing the results through statistical approach. This is commonly used in the health care industry where biological investigations have become a very important part. Quality Control/Quality Assurance (QC/QA) refers to the overall management system which includes the organization, planning, data collection, quality control, documentation, evaluation and reporting activities. With the emerging health issues and availability of modern treatment modalities, it is important to provide the patient, clinical diagnosis with the relevant laboratory investigations. It is therefore, important to maintain the quality control of the testing with a standard degree of precision, which in turn is essential for the delivery of the quality patient care. In view of this, statistical approaches that can be adopted to ascertain the quality of the test have been discussed. The communication also discusses components of validity of the biomedical test and its relevance in clinical settings.
ABSTRACT
Objective To research and evaluate cell counting random error for cell sheet of T lymphocyte subsets in the practical McAb‐A‐E direct method ,and old method of McAb‐A‐E direct method compared .Methods Randomly selected 20 specimens ,cell sheet of T lymphocyte subsets on counting 200 cell at least 2 area from 2/6~4/6 area ,counting area non‐repeated ,CD4+ and CD8+continuous counter 4 times ,CD3+ continuous counter 2 times .Results In the practical McAb‐A‐E direct method ,random error mean of cell counting was separately CD3+ :7 .86 ,CD4+ :9 .99 ,CD8+ :8 .55 ,CD4+ /CD8+ :0 .33 ,lower than old method of McAb‐A‐E direct method ,that was CD3+ :15 .00 ,CD4+ :13 .80 ,CD8+ :10 .70 ,CD4+ /CD8+ :0 .69 .Conclusion Cell counting random error in practical McAb‐A‐E direct method for cell sheet of T lymphocyte subsets is less than old method of McAb‐A‐E direct method .