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【Objective】 To analyze the difference of circulating threshold (Ct) of polymerase chain reaction (PCR) in blood station laboratories during the external quality assessment, and to put forward suggestions for the quality improvement of participating laboratories. 【Methods】 From 2018 to 2021, the blood station laboratories participated in the external laboratory quality assessment of CITIC including blood screening items with nucleic acid testing method. The data of Roche diagnostic reagent group were used as the source, and the detected Ct values of three groups of quality control samples of HBV A subtype (400 IU/mL), HCV 1b subtype (400 IU/mL) and HIV B genotype (500 IU/mL) were used as the objects. The data were grouped according to quality control (sample) batches, reagent batches and different laboratories. Using the statistical method of variance analysis (assuming P<0.05 as significant), the detected Ct value of each group was analyzed. 【Results】 For the three items (HBV/HCV/HIV), the grouping data involving 42 batches of quality control (13/12/17), 28 batches of reagent (11/8/9) and 57 laboratories (19/19/19) were selected. The grouping analysis of quality assessment batches shows that there was no significant difference between HBV and HCV quality assessment batches, and there was no significant difference between other HIV batches except the two batches of HIV quality assessment samples released in 2021. The grouping analysis of each reagent batch showed that there was no significant difference between each reagent batch for HCV and HIV detection, while there was significant difference between two batches of HBV reagents. After excluding the data groups with significant differences in the quality control batch groups and the reagent batch groups, the detected Ct value of each laboratory group had extremely significant differences in the three items of HBV, HCV and HIV. Through pairing analysis, it was found that four laboratories had significant differences with most other laboratories in the three items, mainly manifested in the high mean value of Ct. 【Conclusion】 For the blood station laboratories with correct test results of quality assessment samples, there are differences in Ct values detected by PCR, which may be mainly caused by the detection ability of the participating laboratories.
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Objective:To establish a reasonable and effective formative evaluation system based on the characteristics of practical teaching of medical laboratory to evaluate the effect of practical teaching and improve the quality and level of teaching.Methods:A survey and research method was used to screen the elements needed for the formative evaluation system, so as to construct the framework and evaluation indicators of the practice teaching of this specialty. The students from Batch 2016 were scored before and after implementing formative evaluation, and the results were statistically analyzed by paired t test with SPSS 20.0 software. Results:The survey results of a total of 30 teachers (experts) and 121 students in this major were counted. According to the practical characteristics of this major, the evaluation system included two first-level indicators, five second-level indicators, and corresponding third-level and fourth-level indicators. After statistical analysis, students' learning interest, practical ability, self-learning ability, team assistance ability and knowledge development ability were all significantly improved after the implementation of formative evaluation ( P<0.01- P<0.05), and students' enthusiasm for class also increased ( P<0.05). Conclusion:It proves that the constructed formative evaluation system conforms to the characteristics of practical teaching of medical laboratory, which helps to improve the effect of practical teaching and lays a foundation for its application in the practical teaching of this professional course.
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Objective: To compare setup errors between patients using the customized Klarity AccuCushion® with a thermoplastic fixation mask and patients using a thermoplastic fixation mask or vacuum fixation cushion alone while receiving radiotherapy. Methods: A total of 66 patients with head and neck (H&N) tumors (n=27) or thoracic and abdominal tumors (T&N) tumors (n=39) were included during Jaurnary 2018 to December 2019. 15 H&N cancer patients using only a single head-neck-shoulder mask were categorized into group A; 12 patients using a customized Klarity AccuCushion® and head-neck-shoulder mask were categorized into group B. Among T&A cancer patients, 19 patients using only a vacuum fixation cushion were classified into group A; the remaining 20 patients using a customized Klarity AccuCushion® and thermoplastic fixation mask were classified into group B. Cone-beam computed tomography was performed, and the setup errors were evaluated. The setup errors in the left-right (LR) direction, superior-inferior (SI) direction, anterior-posterior (AP) direction, and for rotation were compared between groups A and B. Results: Among H&N cancer patients, the setup errors in group B in the LR direction, SI direction, and for rotation were 0.06±0.06 cm, 0.08±0.07 cm, and 0.12±0.17°, respectively, which were smaller than those in group A (0.10±0.11 cm, 0.13±0.14 cm, and 0.25±0.47°, respectively). The differences in setup errors in the LR direction, SI direction, and for rotation were significant between the two groups (P0.05). For T&A cancer patients, significant differences were found in setup errors between the two groups (P<0.05) in the LR direction (group B vs. group A: 0.10±0.08 cm vs. 0.14±0.12 cm) and for rotation (group B vs. group A: 0.09 ± 0.18° vs. 0.22 ± 0.39°). No significant differences were observed in the setup errors in the SI and AP directions. Conclusions: Compared with the immobilization techniques using only a thermoplastic mask and only a vacuumed fixation cushion, the technique using a customized Klarity AccuCushion® with a thermoplastic fixation mask can improve repeatability, stability, and setup errors in radiotherapy.
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Objective To investigate the optimal thresholds of the passing rate with different gamma measurement criteria (percent dose difference/DTA) based on the Delta 4 three-dimensional dosimetric verification system in the verification of volumetric modulated arc-therapy (VMAT) plan for cervical cancer.Methods Thirty clinically-approved dual-arc VMAT plans using the RapidArcTM (Varian Medical Systems Inc.) for cervical cancer were randomly selected.The gamma analysis and dose-volume histogram (DVH) evaluation were performed using Delta 4.All the plans were classified according to the following two criteria:1.If the absolute percentage dose errors of all specific dosimetry indices on the DVH were less than 5％,the plan was regarded as clinically acceptable.2.If the gamma passing rate was 90％ or 95％ under the criteria of 2％/2 mm and 3％/3 mm,the plan was regarded as acceptable.The sensitivity and specificity analyses were conducted based on the classification results and the receiver operating characteristic (ROC) curve was plotted.By calculating the Youden Index,the optimal thresholds under different Gamma criteria (global and local 2％/2 mm and 3％/3 mm) were investigated.Finally,the ability of distinguishing the plan was clinically acceptable or not between the conventional and optimal thresholds was quantitatively compared according to the sensitivity and specificity analyses.Results The optimal thresholds under the global 3％/3 mm and 2％/2 mm criteria were 98.3％ and 87.05％;and 97.55％ 、86.05％ for the local gamma analysis.Compared with the conventional thresholds,the sensitivity of the optimal thresholds was 0.93 by using the global and local gamma analyses under the 3％/3 mm criterion.Under the 2％/2 mm criterion,the sensitivity of the optimal thresholds was 0.65 and the specificity was 0.49 by using the global gamma analysis.The sensitivity was 0.7 and the specificity was 0.46 by using the local gamma analysis,suggesting that the sensitivity and the specificity were more balanced under the 2％/2 mm criterion.Conclusions Application of the optimal thresholds in the verification of VMAT plans can maintain the balance between the sensitivity and specificity,prevent the harm of clinically unacceptable plans to patients to certain extent and reduce the probability of increasing the daily work load for physicists due to the misjudgement of clinically acceptable plans.
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Objective To investigate the optimal gamma passing rate of intensity-modulated radiotherapy (IMRT) dosimetric verification in the treatment of esophageal cancer using a three-dimensional dose verification system EDoseTM.Methods Twenty five esophageal cancer patients treated by 7-field IMRT were retrospectively reviewed.Measured dose distribution were reconstructed on CT image and evaluated by gamma analysis and DVH metrics using the EDoseTM system.Plans with DVH metrics dose difference ＜ 5％ or with gamma passing ＞ 90％ under 3％/3 mm criteria were accepted.The optimal gamma passing rate for criteria of 5％/3 mm,3％/3 mm,2％/2 mm were investigated by drawing the receiver operating characteristic (ROC) curves and calculating the Youden Index.The sensitivity and specificity of the these optimal thresholds in the plan verification were also analyzed.Results The optimal thresholds for global gamma indices with 5％/3 mm,3％/3 mm,2％/2 mm were 98.66％,94.84％,78.56％,respectively.In the 90％ common threshold,The sensitivity and specificity for common 90％ threshold and optimal threshold under 3％/3 mm criteria were 0.17 vs.0.85 and t 0.84 vs.0.27,respectively.The sensitivity and specificity were 0.89,0.65 and 0.23,0.47 for optimal thresholds under 5％/3 mm and 2％/2 mm criteria,respectively.Conclusions The sensitivity of optimal threshold gamma passing rate improved significantly compared with the common threshold (90％) at 3％/3 mm criteria.,The sensitivity and the specificity were more balanced at the 2％/2 mm criteria compared with those at 3％/3 mm criteria.
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Objective To study the antioxidant effect of serum bilirubin,an endogenous antioxidants,in the patients with lung cancer. Methods A total of 402 patients with lung cancer(patient group)and 422 healthy individuals(control group)were enrolled in this study. The concentrations of total bilirubin(TBIL)and direct bili-rubin(DBIL)were measured using Diazonium Salts reagent on an automated chemistry analyzer(AU5821,Beck-man Coulter)and concentrations of indirect bilirubin(IBIL)were calculated based on concentrations of TBIL and DBIL. The total activity of SOD and MDA concentrations of 104 patients and 57 controls were measured using Xan-thine oxidase and TBA reagents respectively. All data were analyzed using SPSS 19.0 Software. Results Compared with the control group,the concentrations of TBIL,DBIL,IBIL and the activity of SOD in the patient group were decreased(P < 0.05)but the concentrations of MDA were increased. However,no tendency was found from T1 to T4(TNM)groups. Conclusion There is antioxidant dysfunction within patient with lung cancer and the serum bilirubin would be involved in this process.
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Objective To analyze the MRI findings of pure mucinous breast carcinoma and to investigate the causes of misdiagnosis.Methods MRI findings of 1 3 patients with pure mucinous breast carcinoma were analyzed retrospectively.All patients were verified by surgery and histopathology.Results All the 13 cases were presented as a mass,among which 12 cases (92.3%)had lobular contour and 1 (7.7%) had irregular shape.11 cases (84.6%)showed low or iso-signal intensity and 2 (15.4%)showed heterogeneous iso or high intensity on T1WI.All the 13 cases showed high signal intensity on fat suppression T2WI,and 5 cases(38.5%)showed low signal fiber separation inside. 5 cases (38.5%)showed homogeneous high signal intensity and 8 cases (61.5%)showed heterogeneous high signal intensity on diffusion weighted imaging(DWI)and apparent diffusion coefficient(ADC)map,the ADC value was (2.002±0.478)× 10-3mm2/s.11 cases (84.6%)showed rim enhancement,among which 8(61.5%)showed persistent enhancement and 2 (15.4%)showed heterogeneous enhancement.Time-signal intensity cure(TIC)of 11 cases(84.6%)were monophasic or biphasic and 2 cases(15.4%0)were wash-out type. 5 cases(38.5%)were misdiagnosed on preoperative MRI.Conclusion There are several MRI features in pure mucinous breast carcinoma,such as lobular contour,high signal intensity on DWI and ADC map,persistent enhancement and monophasic or biphasic on TIC.Comprehending these MRI features is the key to reduce misdiagnosis.
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Objective To investigate the value of spectral CT imaging in diagnosis of axillary lymphatic metastasis of breast carcinoma. Methods 27 cases of breast carcinoma who met the criteria underwent dual-phase enhanced spectra CT scan.The axillary lymph nodes were matched one-to-one between CT images and postoperative pathology.The four parameters,including NIC-A,NIC-V, λHU-A,and λHU-V were analyzed among primary tumors,metastasis and non-metastasis lymph nodes.The area under receiver operating characteristic (ROC)curves of the four parameters were used to evaluate the diagnostic accuracy in axillary lymphatic metastasis.Results The four parameters showed significant differences among the primary tumors,metastasis lymph nodes and non-metastasis lymph nodes. The four parameters were also significantly different between the primary tumors and non-metastasis lymph nodes,between metastasis lymph nodes and non-metastasis lymph nodes.Only NIC-V was significantly different between the primary tumors and metastasis lymph nodes.When NIC-A value of 0.148 was used as the threshold for diagnosing lymphatic metastasis,the sensitivity,specificity and the area under the curve were 80.00%,84.62% and 0.888,respectively.Conclusion The parameters of spectral CT imaging can significantly improve the diagnostic accuracy of axillary lymphatic metastasis of breast carcinoma,which can be used as a reference for clinical diagnosis.
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Objective To evaluate the diagnostic performance of enhancement value and morphological features by using mul-tiphasic MDCT on differentiating untypical T4a from T3 gastric cancer.Methods Fifty-one histopathologically proven T3 and T4a gastric cancer patients with smooth serosa were collected retrospectively.Three radiologists read all images regarding morphological features,while the CT value and enhancement value of regions of interest (ROIs)located in the outer of lesion were calculated.Cut-off analysis was performed to determine optimal threshold levels of enhancement value to discriminate T4a and T3 gastric cancer.Di-agnostic performance of enhancement value and combination of enhancement value and morphologic assessment were compared with morphologic assessment by means of receiver operating characteristic (ROC)curve analysis.Results The sensitivity and specificity of morphological features was 66.67% and 33.33% respectively;the area under the ROC of enhancement value (between venous phase and plain scan)for differentiating T4a from T3 gastric cancer was 0.82,with a cut-off at 43.6 HU,sensitivity of 74.07% and specificity of 70.83%.Combined conventional standard and enhancement value,sensitivity of 100.00% and specificity 26.31%. Conclusion For differentiation of T4a and T3 gastric cancer by means of MDCT,enhancement value is found to be superior to con-ventional standard.
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Objective To investigate the diagnostic value of DWI on nasopharyngeal neoplasm recurrence and fibrotic lesions after radiotherapy.Methods A retrospective analysis of pathologically confirmed nasopharyngeal neoplasm was performed in 39 patients with recurrent patients ( recurrence group ) confirmed by biopsy or MRI follow-up and 51 patients with confirmed localized fibrosis (fibrosis group) after radiotherapy.All patients underwent DWI , non-enhanced and enhanced MR scan.DWI findings and ADC values of the lesions in two groups of patients were observed and measured , then compared by using independent samples t test.Diagnostic performance of routine MRI and DWI in the diagnosis of nasopharyngeal neoplasm recurrence after radiotherapy was calculated by using ROC analysis and the differences of both of them were analyzed by using Z test.Results DWI of 39 recurrent patients showed hyper-intensity signal and ADC map showed hypo-intensity signal appearance.Overall signal of DWI in 51 recurrent patients is lower than that in recurrent group , in which ADC maps of 36 cases showed iso-intensity or moderately hypo-intensity signal appearance and the remaining 15 cases showed moderate hyper-intensity signal appearance.The ADC values of recurrent group and fibrotic group were (0.753 ±0.127) × 10 -3 mm2/s, and ( 1.233 ± 0.310 ) ×10 -3 mm2/s, respectively.The difference was statistically significant ( t=-9.118, P<0.05).On the ROC curve, the sensitivity of ADC for the diagnosis of tumor recurrence was 87.18%(34/39), specificity 94.12%(48/51) and area under the ROC curve 0.968 with the ADC cutoff value of 0.887 ×10 -3 mm2/s.The sensitivity of routine MRI was 71.79% ( 28/39 ) , the specificity 74.51% ( 38/51 ) and the area under the ROC curve was 0.732 for the diagnosis of tumor recurrence.The difference of area under the curve between them was statistically significant ( Z=4.583, P<0.01).Conclusion DWI can help tumor detection and diagnosis of recurrent nasopharyngeal neoplasm and has a higher diagnostic performance compared with routine MRI.
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Objective To study the diagnostic value of 1.5T diffusion-weighted magnetic resonance imaging for small metastatic cervical lymph nodes of nasopharyngeal carcinoma(NPC),and to explore the optimal diagnostic threshold value of apparent diffusion coefficient(ADC)in small metastatic cervical lymph nodes of NPC.Methods 40 patients with histopathologically confirmed NPC were underwent conventional,enhanced and DWI MR.The mean ADC value of large metastatic cervical lymph nodes group,small metastatic cervical lymph nodes group and benign lymph nodes group were measured respectively.Statistical analysis was done by using the SPSS 1 6.0 program software.The receiver operating characteristic (ROC)curve was performed to obtain the ADC thresh-old value of small metastatic cervical lymph nodes and the diagnostic efficacy.Results The mean ADC value of large metastatic cer-vical lymph nodes group was (0.74±0.1 1)×10 -3 mm2/s,which was not significantly different from that in small metastatic cervical lymph nodes group(0.75±0.13)×10 -3 mm2/s,P >0.05.The mean ADC value in benign lymph nodes group was (1.05± 0.18)× 10 -3 mm2/s,which was significantly higher than that in large metastatic cervical lymph nodes group and small metastatic cervical lymph nodes group(P <0.05 ).Using a threshold ADC value of 0.908 × 10 -3 mm2/s for differentiating small metastatic cervical lymph nodes from benign lymph nodes,a sensitivity of 83.2% and specificity of 90.9% were obtained,the area under the ROC curve was 0.92.Conclusion DWI is helpful in the diagnosis of small metastatic cervical lymph nodes of NPC.
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ObjectiveTo investigate the effect of different reference vessel groups on CT perfusion in patients with nasopharyngeal carcinoma (NPC) after radiation therapy,and explore the feasibility of substitution of reference vessel.MethodsThirty patients with NPC after radiation therapy were divide into two groups,recurrence group ( n =19) and fibrosis group ( n =11 ).All patients underwent CT perfusion scans,and the CT parameters were calculated with different arterial input and vein output in order to study their differences.The vessels were internal carotid artery-internal jugular vein( ICA-IJV group),external carotid artery-retomandibular vein (ECA-RTV group)and external carotid artery-internal jugular vein( ECAIJV group) respectively.The differences of the CT parameters between local recurrence group and fibrosis group were compared among the various vessel groups by rank sum test.With the help of receiver operating characteristic curve (ROC),the diagnostic efficiencies were compared by the area under the ROC curve (AUC).ResultsIn ICA-IJV group,ECA-RTV group and ECA-IJV group,bloood flow(BF) of local recurrence group were 201.88,439.59,252.23 ml · min-1 · 100 g-1,while BF of fibrosis group were 98.96,180.50,106.55 ml · min-1 · 100 g-1.Blood volume (BV) of local recurrence group were 6.71,12.39,6.70 ml/l00 g,while BV of fibrosis group were 2.35,4.76,2.95 ml/100 g.Mean transit time (MTT) of local recurrence group were 1.66,1.50,1.56 s,while MTT of fibrosis group were 2.13,1.96,1.79 s.Permeability surface (PS) of local recurrence group were 19.31,36.39,15.22 ml · min- 1 ·100 g-1,while they were 16.58,29.08 ,16.63 ml · min-1 · 100 g-1 in the fibrosis group.The differencesof BF and BV between the local recurrence group and fibrosis group were statistically significant in each vessel group (P ＜ 0.05 ) but MTT and PS showed no significant difference( P ＞ 0.05 ).In ICA-IJV group,the AUC of BF,BV,MTT,PS were 0.909,0.947,0.677,0.703,respectively.BF,BV,MTT,PS in ECA-RTV group were 0.938,0.967,0.648,0.679 respectively,and those in ECA-IJV group were 0.861,0.890,0.641,0.656 respectively.However,AUC of BF and BV of three groups all had significant difference ( P ＜ 0.01 ).ConclusionsBoth BF and BV values calculated by three pairs of reference vessels had enough diagnosis efficiency for local recurrence and fibrosis,so all of the three groups of vessels may substitute each other in CT perfusion.
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Objective To analyze the second time blood screening results of ALT deferred donors,and to evaluate the importance of alanine aminotransferase(ALT) testing on the improvement of blood safety.Methods The ALT testing results of 565 360 blood donors from Feb.2006 to Jan.2008 of Shanghai Blood Center were studied retrospectively.The screening results and donation intervals of such donors who delayed their donation just because of their former unqualified ALT level were also analyzed.Results A total of 32 042 donors(5.67%) failed in ALT testing among 565 360 donors.And 3 395 ALT deferred donors participated the second time blood donation,among which 2 205(64.95%) passed the blood screening tests,while the other 1 190(35.05%) failed.Among the 1 190 unqualified blood donors,1 151(33.90%)failed again in ALT testing,and 11(0.32%) in Syphilis,12(0.35%) in HBsAg,7(0.21%) in anti-HCV and 1 in anit-HIV(0.03%).Meanwhile,donors failed both in ALT testing combined with HBsAg,anti-HCV,and anit-HIV sero-converted were 1(0.03%),2(0.06%) and 1(0.03%),respectively.And 72.64% of ALT deferred donors participated the second time blood donation within 6 months.The average donation intervals of donors with qualified ALT level but sero-converted were 140 days(from 24 to 267 days),and those with both unqualified ALT level and sero-converted were 158 days(from 91 to 220 days).Conclusion Before the new methods such as NAT were applied to blood donation screening system,ALT test could prevent the window-period failure of ELISA screening so as to improve the blood safety.
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0.05).Conclusion The parameters of CT perfusion can be regarded as a surrogate index of tumor angiogenic activity pre-and post-radiotherapy in nasopharyngeal carcinoma.
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A gas chromatographic method has been developed for determining glycerin concentrations of both therapeutic and physiological levels in serum. The linear relationship was obtained in the range of 1.6-800 ug/ml and the coefficient variations determined within a day and between days were 2.2% and 2.4% respectively. Recoveries of glycerol from serum were about 87%.