Objective To analyze the expression and predictive value of serum tumor markers spectrum and chemokine protein in lung cancer and predictive value.Methods One hundred and fifty patients with lung cancer were selected as the observation group and contemporaneous 150 individuals undergoing physical examination served the control group.The levels of ProGRP,CEA,SCC and Cyfra21-1 were measured by chemiluminescence microparticle immunoassay.The chemokine protein was determined by multiple immunofluorescent assay.Results The levels of CCL28,LIF,LIGHT and GRO in the observation group were significantly higher than those in the control group (P＜0.05).The levels of CCL28,LIF,LIGHT and GRO in the observation group were higher than those in the control group.The levels of CCL28,NAP-2 and MDC in the observation group were lower than those in the control group (P＜0.05).Conclusion The regular detection of serum tumor markers spectrum and chemokine protein can predict the treatment prognosis and evaluate the clinical curative effect.

Objective:To explore the expression of long-chain noncoding RNA (lncRNA) and myocardial infarction-associated transcription (MIAT) in Leukocyte differentiation antigen (CD)4+T cells in peripheral blood of gastric cancer patients and its value of clinical application.Methods:Peripheral blood CD4+T cells were collected from 124 patients with gastric cancer, 90 benign gastric diseases patients and 80 healthy controls enrolled in Taizhou People′s Hospital from January 2019 to April 2021. The expression levels of MIAT and N6-methyladenosine(m6A) binding to MIAT promoter in CD4+T cells were detected by real-time fluorescent quantitative polymerase chain reaction (qPCR) and Chromatin immunoprecipitation (ChIP)-qPCR, respectively. Spearman test was used to analyze the correlation between MIAT and clinicopathological features, as well as between MIAT and regulatory T cell levels. The receivor operating characteristic curve (ROC) of the subjects was used to evaluate the MIAT expression level in the auxiliary diagnostic value of gastric cancer.Results:The relative expression levels of MIAT in the gastric cancer patients, the benign gastric diseases patients, and the healthy controls were 2.849 (2.131, 4.062), 1.511 (0.916, 1.855) and 0.963 (0.729, 1.432), respectively. The difference among the three groups was statistically significant ( H=158.25, P<0.001). The relative expression level of MIAT in the gastric cancer patients was significantly higher than the levels in the benign gastric diseases patients and healthy controls. The difference was statistically significant ( Z=100.63, 145.14, P<0.001). The binding activity of m6A to MIAT promoter in patients with early stage (stage Ⅰ and Ⅱ) and end stage (stage Ⅲ and Ⅳ) gastric cancer was 8.590±1.483 and 4.274±0.425, respectively. The difference was statistically significant ( t=6.255, P=0.002). Furthermore, the binding activity of m6A to MIAT promoter in the gastric cancer patients was significantly lower than that in patients with benign gastric diseases (17.267±3.106) and healthy controls (27.637±3.945) ( t=-7.331,-12.832, P<0.001). The relative expression of MIAT in CD4+T cells in peripheral blood of the gastric cancer patients had no significant difference in age(χ2=0.000, P=1.000), gender(χ2=0.000, P=1.000), CEA (χ2=0.648, P=0.421) and CA199(χ2=1.554, P=0.213), but had significant difference with tumor size expression(χ2=9.443, P<0.01), TNM stage(χ2=23.571, P=0.002) and lymph node metastasis (χ2=45.248, P<0.01). In addition, there was a significant positive correlation between the relative expression of MIAT in CD4+T cells and Treg level ( r2=0.76, P<0.001). The diagnostic efficacies of MIAT in CD4+T cells, CEA and CA199 in the gastric cancer patients were analyzed by ROC curve. When compared with patients with benign gastric diseases, the areas under the curve were 0.879, 0.635 and 0.611, respectively. When compared with healthy patients, the areas under the curve were 0.953, 0.784 and 0.598, respectively. Conclusions:The level of MIAT in CD4+T cells in peripheral blood of patients with gastric cancer is significantly higher than the levels in patients with benign gastric diseases and the healthy controls, which may be related with the decreased activity of m6A binding to the promoter of MIAT. The level of MIAT in CD4+T cells may be a relevant biomarker for the diagnosis and prognosis of gastric cancer.

Objective improve the accuracy of the measurement results by using the field output factor measurement method based on daisy-chaining.Methods The Varian Edge Accelerator 6 MV X-ray data were measured using the IBA CC13 ionization chamber, IBA CC01 ionization chamber, IBA Razor semiconductor detector , IBA EFD semiconductor detector and Gafchromic EBT 3 film , respectively. Results Compared with the daisy-chaining measurement method,the results obtained by the conventional measurement method using CC13 were smaller. The deviation value was 16. 71% in the 1 cm × 1 cm field. The measurement results in a larger field via CC01 were bigger with a deviation of 8. 39% in the 40 cm × 40 cm filed. The measurement results via Razor in a larger field were larger with a deviation of 9. 40% in the 40 cm × 40 cm field. The measurement results were similar between EFD and Razor with a deviation of 9. 14% in the 40 cm × 40 cm field. The results of the film measurement were equivalent to those obtained from the daisy-chaining method in a field of＞ 1 cm × 1 cm with a deviation within 1. 60%,whereas the deviation was increased to 3. 13% in the 1 cm× 1 cm field. The results were consistent with daisy-chaining measurement if the 3 cm × 3 cm or 4 cm × 4 cm fields were selected as the intermediate fields with the maximum deviation of 0. 29%. Conclusions For the detectors with changing response along with the field size,daisy-chaining measurement method can be utilized to extend the measurement range and improve the accuracy of the measurement results.

Objective The IAEA report No.483 describes the latest method of small field dosimetry.The field output factor measurement and correction methods are used to improve the accuracy and consistency of the measurement results for different type detectors.Methods The field output factors from 0.6 cm×0.6 cm to 10 cm× 10 cm were measured using IBA's CC13 ionization chamber,CC01 ionization chamber,PFD semiconductor detector,EFD semiconductor detector and Razor semiconductor detector,respectively.The field output correction factors were used to correct the measurement result.Results Compared with the corrected data,the results of ionization chamber are mainly affected by the volume averaging and the fluence perturbation effect,lead to the measurement result which is 4.70％ lower at 0.6 cm × 0.6 cm;The results of Shielded semiconductors are mainly affected by fluence perturbation effect,lead to the measurement result which is 4.80％ higher at 0.6 cm × 0.6 cm.The results of unshielded semiconductors are mainly affected by energy response and fluence perturbation effect,resulting in lower measurement results at the field size＞0.8 cm×0.8 cm,2.10％ lower at field size of 1.5 cm× 1.5 cm,higher measurement results at field size＜0.8 cm×0.8 cm and 1.1％ higher at field size of 0.6 cm×0.6 cm.Before the correction,the measurement results from different types of detectors are quite different,average standard deviation is 0.016 6.After the correction,the difference among the detectors is significantly reduced,average standard deviation is 0.006 6.Conclusions For detectors such as ionization chambers and semiconductors,the field output correction factors can be used to correct the output factors of the small field to improve the accuracy and consistency of the measurement results.

Objective:To introduce the clinical dosimetry commissioning methods and results of the 1.5 T MR-linac.Methods:In May, 2019, an Elekta Unity 1.5 T MR-linac was installed in Cancer Hospital, Chinese Academy of Medical Sciences and dosimetry commissioning was performed with magnetic field compatible measuring instruments. Commissioning items include absolute dose calibration, data acquisition and planning system model verification.Results:Absolute dose calibration in magnetic field should be corrected by magnetic field correction factor. The standard output dose of Unity was 87 cGy. Gamma analysis (3%/2 mm) was performed on the beam collection data and the planning system calculation data. The average pass rate of dose verification of standard field test cases was 96.41%, and the TG119 test case was 98.24%. The IROC end to end test case was 97.5%(7%/4 mm).Conclusions:The planning system model and the beam collection data have good consistency. The dose verification results of the standard field and TG119 test cases meet the general tolerance limit requirements of the AAPM TG218 report, and the verification results of the IROC end-to-end test cases meet the IROC center standards.

Objective:To evaluate the effect of fast cone beam CT (CBCT) scan mode on image quality and registration results, and to establish the scanning pre-settings for fast CBCT.Methods:Three scanning modes were utilized to the CBCT phantom, and the registration accuracy and image quality were quantitatively evaluated. The correlation and consistency of measurement results under different scanning modes were further verified by 278 sets of CBCT data from 33 clinical tumor patients.Results:The maximum deviation between the measurement results of three scanning models and the actual value was 0.70 mm (0.51 mm on average). The measurement results of the same location were consistent among three scanning modes (0.00 mm). For the uniformity, the results of the normal mode were the best (3.62% on average), followed by the fast 1 mode (3.90% on average) and the fast 2 mode (4.84% on average). For the noise, the results of the normal mode were the best (15.69 on average), followed by the fast 2 mode (17.23 on average) and the fast 1 mode (21.74 on average). Regarding the high contrast resolution, the measurement results of three scanning modes were consistent (at least 3 pairs could be distinguished). For the low contrast resolution, the results of the fast 1 mode were the best (1.69 on average), followed by the normal mode (2.10 on average), and the fast 2 mode (2.31 on average). For the geometric accuracy, the measurement results of the three scanning modes were basically consistent with a mean deviation of 0.05 mm. The correlation of the measurement results between normal mode and fast 1 mode was the highest in clinical cases ( R2>0.90, P<0.01) with a high degree of consistency (95% consistency limit of the above two scanning modes< 1 mm threshold). Conclusion:Compared with the normal mode, the fast 1 mode can yield equivalent image quality, consistent registration results, faster scanning speed and lower scanning dose. Therefore, the fast 1 mode is recommended as the scan mode in clinical practice.