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Objective:The characteristics of women with false elevated testosterone were analyze and the literature was reviewed to provide reference for clinical laboratory identification of false elevated testosterone.Methods:The characteristics of three patients with false elevated testosterone in Peking Union Medical College Hospital were analyzed retrospectively, and the results of different detection platforms and methods for the determination of testosterone levels were compared. International and domestic literatures related to false elevation of testosterone and detection methods of testosterone were searched for a comprehensive analysis from PUBMED and CNKI.Results:The levels of testosterone in 3 female patients were elevated by immunoassay and normal by mass spectrometry. They were excluded from the diagnosis of hyperandrogenemia. A total of 38 literatures related to testosterone detection were retrieved, of which 9 case reports of pseudohyperandrogenemia, among which 12 cases of pseudohyperandrogenemia were reported in 2 domestic literatures in 2021. All cases were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Previous studies have clearly indicated that the result of routine immunoassay in clinical laboratory for the determination of female testosterone have poor correlation with the results of LC-MS/MS, with varying degrees of deviation.Conclusions:Immunoassay tests for female testosterone is susceptible to interference and lead to elevated false results. It is suggested that clinical laboratories evaluate the detection methods used and establish a identification program, and confirm samples with suspected pseudoelevated testosterone elevation using other immune platforms or LC-MS/MS.
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Objective:To compare and analyze the differences in the setup accuracy of different immobilization method in breast cancer radiotherapy after breast-conserving surgery.Methods:A retrospective study was conducted on 60 patients who received radiotherapy after breast-conserving surgery from January to August, 2021. These patients were divided into two groups. One group consisted of 30 cases who were immobilized using a modified body thermoplastic membrane combined with a multifunction body board during the breast cancer radiotherapy and was called the modified body thermoplastic membrane group. The other group comprised 30 cases immobilized using a vacuum cushion during breast cancer radiotherapy and was referred to as the vacuum cushion group. The setup errors, 3D vector errors, the proportion of errors of > 5 mm, and the dosimetric differences in the planning target volume (PTV) and the clinical target volume (CTV) before and after simulated treatment bed moving (including the PTV_ V100, PTV_ V95, and CTV_ V95 before simulated treatment bed moving and the PTV_ V100 S, PTV_ V95 S, and CTV_ V95 S after simulated treatment bed moving) were compared between two groups. Moreover, for the modified body thermoplastic membrane group, the changes in the average setup errors at different radiotherapy stages were also analyzed. Results:A total of 369 cone-beam CT scans were conducted for 60 patients, including 195 CT scans for the modified body thermoplastic membrane group and 174 CT scans for the vacuum cushion group. The setup errors in the x, y, and z directions (right-left, anterior-posterior, and superior-inferior, respectively) of the modified body thermoplastic membrane group were (2.59±1.98) mm, (2.38±2.04) mm, and (1.45±1.16) mm, respectively, while those of the other group were (2.24±1.63) mm, (2.78±2.17) mm, and (2.70±1.88) mm, respectively. The 3D vector errors of both groups were (4.32±2.28) mm and (5.13±2.14) mm, respectively. Therefore, the setup error in direction z and the 3D vector error of the modified body thermoplastic membrane group were less than those of the vacuum cushion group ( t = -7.77, -3.41, P<0.05). Moreover, the proportion of setup errors of > 5 mm in the x direction of the vacuum cushion group was lower than that of the modified body thermoplastic membrane group ( χ2 = 7.13, P<0.05), while such proportion in the z direction of the modified body thermoplastic membrane group was lower than that of the vacuum cushion group ( χ2= 5.90, P<0.05). After the simulated treatment bed moving, the PTV_ V100 S of the modified body thermoplastic membrane group was better than that of the vacuum cushion group ( t = 2.47, P < 0.05). Furthermore, for the modified body thermoplastic membrane group, the setup errors in the x direction in the first week were higher than those in the 2-3 weeks and 4-5 weeks ( P<0.05). Conclusions:The modified body thermoplastic membrane combined with a multifunction body board yield better immobilization effects than a vacuum cushion. However, it produces high setup errors in the x direction in the first week of the radiotherapy, to which special attention should be paid.
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Objective:To evaluate the performance of magnetic beads extraction method (MGE) for the measurement of catecholamine metabolites by liquid chromatography tandem mass spectrometry.Methods:This is a methodological evaluation study. The linearity, limit of quantitation, recovery, precision, and matrix effect of catecholamine metabolites 3-methoxyepinephrine (MN), 3-methoxynorepinephrine (NMN) and 3-methoxytyramine (3-MT) extracted by MGE method were evaluated according to CLSI C62-A. Consensus of method development and validation of liquid chromatography-tandem mass spectrometry in clinical laboratories and other guidelines, 132 clinical residual plasma samples were collected and extracted by automated MGE and traditional solid phase extraction (SPE) method to compare the harmonization of the two extraction methods.Results:The linearity of MN, NMN and 3-MT extracted by automated MGE was>0.99, and the LOQ for MN, NMN and 3-MT were 0.033 5 nmol/L, 0.054 7 nmol/L and 0.011 0 nmol/L, respectively. The repeatability of MN, NMN and 3-MT were 1.3%-5.1%, 2.2%-5.6% and 1.7%-7.1%, respectively. The total imprecision in the laboratory were 1.5%-8.2%, 2.2%-7.7%, 2.1%-11.2%. Although the absolute recovery is low, the average relative recoveries of MN, NMN and 3-MT were 91.5%-108.5%, 92.0%-108.6%, and 89.3%-104.1%, respectively, and the percentage deviation from the expected concentration was within 15%. After isotope internal standard correction, the relative matrix effect is close to 100%, which can compensate for the potential matrix effect. The results of MGE and SPE of MN, NMN and 3-MT showeda good correlation (correlation coefficient r>0.99). The average relative deviations of MN, NMN and 3-MT were 0.2%, -1.4% and 1.0%, respectively. Conclusion:The automatic MGE method hasa good performance in extracting catecholamine metabolites, and is expected to be used in high-throughput analysis of samples in clinical in the future.