Objective To investigate the best exposure condition for reducing the radiation dose of the chest radiography and obtaining the good quality of images. Methods With different tube voltage (kVp), tube current & time (mAs), and focus-film distance(FFD) adopted, X-ray detecting phantom was exposed by means of automatic exposure control(AEC). The dosage absorbed in skin was detected; Spatial resolution capacity, low contrast resolution capacity and low contrast sensitive degree were tested. The space and density resolution capacity were tested. The chest image quality was appraised by the way of visual observation and the measure of film density. Results The different kVp and FFD were related to the emitting skin dose (ESD), the higher kVp and the farther FFD follows the lower ESD; the higher or lower mAs has no effect on the image resolution capacity , but it had effect on image noise. The density value and seeing effect of chest film with low dose had reached good image density and needs of diagnostics. Conclusion Under the condition of 120 kVp high voltage, FFD150cm, AEC reduced density and adjusting to the processing parameters of the CR chest images, the radiation dosage of the chest computed radiography can be reduced efficiently and the good quality of images can be obtained.

Objective To investigate the efficacy and toxicity of stereotactic ablative radiotherapy for stage Ⅰ peripheral non-small cell lung cancers.Methods Thirty six patients of stage Ⅰ peripheral non-small cell lung cancers were treated with stereotactic ablative radiotherapy.The prescription dose was 12 Gy per fraction ×4 fraction in one to two weeks.The 100％ planning target volume (PTV) was covered by the isodose curve of 95％ prescription dose.Organs at risk and their respective tolerance doses used during treatment planning were developed from the research scheme of the Radiation Therapy Oncology Group 0236.Before the radiation delivery,all patients were scanned by the fan beam CT or the cone beam CT for image guidance and registration.The follow-up for the patients was given to observe the toxicity and efficacy of stereotactic ablative radiotherapy (SABR).Results The median follow-up time was 18.7 months (range of 4 to 36 months).After treatment,the overall response rate was 88.9％,with complete response (CR) 17 cases(47.2％),partial response (PR) 15 cases(41.7％),and stable disease (SD) 4 cases(11.1％).The estimated overall survival rate at 1 and 3 years was 92.3％ (95％ confidence interval [CI],86.3％ ～97.1％) and 85.3％ (95％ CI,80.5％ ～90.6％).The estimated local control rate at 3 years was 90.2％ (95％ CI,85.7％ ～94.8％).There was no gradeⅢ or above toxicity related to treatment.Conclusions The stereotactic ablative radiotherapy attains good local control and survival efficacy for the stage Ⅰ peripheral non-small lung cancer patients.It is well tolerated owing to low toxicity.

Objective:To explore the antitumor effect of ADU-S100/doxorubicin in situ vaccine on diffuse large B-cell lymphoma (DLBCL) and its mechanism.Methods:The 6-week-old female BALB/c mice were selected, and the bilateral murine subcutaneous B-cell lymphoma model was established with murine B-cell lymphoma A20 cells. The subcutaneous tumor-bearing mice were randomly divided into untreated group (without treatment), ADU-S100 in situ vaccine treatment group (intratumoral injection of interferon gene stimulating factor agonist ADU-S100), doxorubicin in situ vaccine treatment group (intratumoral injection of doxorubicin), and ADU-S100/doxorubicin in situ vaccine treatment group (intratumoral injection of ADU-S100 and doxorubicin) by using random number table method, with 5 mice in each group. The right tumors of the bilateral subcutaneous tumor-bearing mice were defined as proximal tumors, and the left tumors of the bilateral subcutaneous tumor-bearing mice were defined as distal tumors. Only the proximal tumors were treated via the intratumoral route, and the distal tumors were not treated. On day 23 after tumor inoculation, the percentages of CD11c + dendritic cells (DC), CD8 + CD11c + DC and CD80 + CD11c + DC in the spleen of mice in each group were detected by flow cytometry. The splenocytes of mice in each group were stimulated with A20 tumor cell lysate in vitro, the percentages of 5'-ethynyl-2'-deoxyuridine-positive (EdU +) cells and tumor necrosis factor-α-positive (TNF-α +) cells in CD8 + T cells in each in situ vaccine treatment group were detected by flow cytometry, and the killing effect of cytotoxic T lymphocyte (CTL) in each group was measured by using the lactate dehydrogenase (LDH) cytotoxicity assay kit. The mice treated with ADU-S100/doxorubicin in situ vaccine were intraperitoneally injected with anti-mouse CD8α (clone 53-6.7) mAb or isotype control on days 7, 12 and 17 after tumor inoculation to eliminate CD8 + cells. On day 23 after tumor inoculation, the proximal and distal tumor volumes of mice in the ADU-S100/doxorubicin in situ vaccine combined with anti-mouse CD8α (clone 53-6.7) mAb or isotype control treatment group were measured, the percentages of CD8 + T cells and CD8 + CD11c + DC in the spleen of tumor-bearing mice in these two groups were detected by flow cytometry, and the infiltration of CD8 + T cells in the tumor tissues from these two groups was detected by immunohistochemistry (IHC) staining. Results:On days 11, 14, 17, 20 and 23 after tumor inoculation, the proximal and distal tumor volumes of mice in each treated group were lower than those in the untreated group (all P < 0.05). The proportions of CD11c + DC in the spleen of the untreated group, ADU-S100 in situ vaccine treatment group, doxorubicin in situ vaccine treatment group and ADU-S100/doxorubicin in situ vaccine treatment group were (4.92±0.63)%, (7.54±0.84)%, (7.45±0.86)% and (11.63±0.85)%, respectively, and the difference was statistically significant ( F = 72.30, P < 0.001); the proportions of CD8 + CD11c + DC were (1.36±0.34)%, (4.02±0.43)%, (4.22±0.61)% and (6.11±0.73)%, respectively, and the difference was statistically significant ( F = 76.09, P < 0.001); the proportions of CD80 + CD11c + DC were (0.51±0.24)%, (1.69±0.23)%, (1.82±0.25)% and (4.09±0.39)%, respectively, and the difference was statistically significant ( F = 167.40, P < 0.001). The CTL responses and the proportion of EdU + cells and TNF-α + cells in CD8 + T cells in each in situ vaccine treatment group were higher than those in the untreated group (all P < 0.05). Furthermore, the enhanced CTL responses and the increased proportion of EdU + cells and TNF-α + cells in CD8 + T cells were observed in the ADU-S100/doxorubicin in situ vaccine treatment group as compared to the ADU-S100 in situ vaccine treatment group and doxorubicin in situ vaccine treatment group (all P < 0.05). The proportions of CD8 + T cells and CD8 + CD11c + DC in the spleen of mice treated with ADU-S100/doxorubicin in situ vaccine and anti-mouse CD8α mAb were lower than those in ADU-S100/doxorubicin in situ vaccine and isotype control group (both P < 0.05) and both proximal and distal tumor volumes of mice treated with ADU-S100/doxorubicin in situ vaccine and anti-mouse CD8α mAb were larger than those in ADU-S100/doxorubicin in situ vaccine and isotype control group (both P < 0.05). Conclusions:ADU-S100/doxorubicin in situ vaccine can induce profound regression of proximal tumors in bilateral murine subcutaneous B-cell lymphoma model and generate systemic immune responses capable of partially inhibiting distant tumor growth, and the antitumor efficacy of ADU-S100/doxorubicin in situ vaccine may require CD8 + CD11c + DC-mediated CD8 + T cell immune responses.

Objective To explore whether stimulator of interferon genes(STING)agonist ADU-S100 could enhance the antitumor immune response of a chitosan(CS)nanoparticle-mediated DNA vaccine containing a tumor-specific antigen Dickkopf-related protein 1(DKK1)in multiple myeloma(MM).Methods CS-DNA nanoparticles were prepared by using the compound coprecipitation method.The particle sizes and Zeta potential of the CS-DNA nanoparticles were measured by using the Zetasizer Nano-ZS laser particle size analyzer.The DNA protection effect and in vivo DNA expression efficiency of the CS-DNA nanoparticles were assessed by using gel retardation assay and Western blot,respectively.The lentiviruses expressing human DKK1(hDKK1)genes were used to establish MPC-11 cells(MPC-11-hDKK1)which stably expressed hDKK1,and the MPC-11-hDKK1 cells were subcutaneously given to mice to construct tumor models.The tumor-bearing mice were randomly divided into a control group(intramuscular injection of CS-pcDNA3.1),an ADU-S100 immunization group(subcutaneous injection of ADU-S100),a CS-pDKK1 immunization group(intramuscular injection of CS-pDKK1)and an ADU-S1OO/CS-pDKK1 co-immunization group(intramuscular injection of CS-pDKK1+subcutaneous injection of ADU-S100),with 5 mice in each group.The tumor-bearing mice in each group were immunized 3 times at 10-day intervals according to the corresponding immunization schedule.The size of tumor was measured every week.On day 42 after MPC-11-hDKK1 cell inoculation,the tumor weight of mice in each immunization group was measured;the percentages of CD11c+dendritic cell(DC),CD8+CD11c+DC and major histocompatibility complex class Ⅱ(MHCII)+CD11c+DC subsets in the spleen of mice in each immunization group were detected by using flow cytometry.The splenocytes of mice in each group were stimulated with recombinant hDKK-1 protein in vitro,the percentage of EdU+cells in CD8+T lymphocytes in each immunization group was detected by using flow cytometry,and the killing effect of cytotoxic T lymphocyte(CTL)in each group was assessed by using the lactate dehydrogenase(LDH)cytotoxicity assay kit.Results The particle size and Zeta potential of the CS-DNA nanoparticles were(204.3±2.31)nm and(15.47±1.01)mV,respectively.Gel retardation assay showed that DNA enveloped in CS nanoparticles could be completely retarded.Western blot analysis indicated that CS-DNA nanoparticles could be effectively expressed in vivo.The relative expression of DKK1 protein was significantly higher in MPC-11-hDKK1 cells than in MPC-11-Ctrl cells(P＜0.05).On days 7 and 14 after MPC-11-hDKK1 cell inoculation,there was no significant difference in tumor volume of mice between the ADU-S100 immunization group,CS-pDKK1 immunization group,ADU-S100/CS-pDKK1 co-immunization group and the control group(P＞0.05);on days 21,28,35 and 42 after MPC-11-hDKK1 cell inoculation,the tumor volumes of mice in the ADU-S100 immunization group,CS-pDKK1 immunization group and ADU-S100/CS-pDKK1 co-immunization group were significantly lower than those in the control group(P＜0.05);the tumor volume of mice in the ADU-S100/CS-pDKK1 co-immunization group was significantly lower than that in the ADU-S100 immunization group and CS-pDKK1 immunization group(P＜0.05).On day 42 after MPC-11-hDKK1 cell inoculation,the tumor weight of mice in the ADU-S100 immunization group,CS-pDKK1 immunization group and ADU-S1 OO/CS-pDKK1 co-immunization group was significantly lower than that in the control group(P＜0.05);the tumor weight of mice in the ADU-S100/CS-pDKK1 co-immunization group was significantly lower than that in the ADU-S100 immunization group and CS-pDKK1 immunization group(P＜0.05).The proportions of CD11c+DC,CD8+CD11c+DC and MHCII+CD11c+DC subsets in the spleen of mice in the ADU-S100 immunization group,CS-pDKK1 immunization group and ADU-S100/CS-pDKK1 co-immunization group were significantly higher than those in the control group(P＜0.05).The proportions of CD11c+DC,CD8+CD11c+DC and MHCII+CD11c+DC subsets in the spleen of mice in the ADU-S100/CS-pDKK1 co-immunization group were significantly higher than those in the ADU-S100 immunization group and CS-pDKK1 immunization group(P＜0.05).The CTL killing effect and the proportion of EdU+cells in CD8+T lymphocytes in the ADU-S100 immunization group,CS-pDKK1 immunization group and ADU-S1OO/CS-pDKK1 co-immunization group were significantly higher than those in the control group(P＜0.05);the CTL killing effect and the proportion of EdU+cells in CD8+T lymphocytes in the ADU-S100/CS-pDKK1 co-immunization group were significantly higher than those in the ADU-S100 immunization group and CS-pDKK1 immunization group(P＜0.05).Conclusion STING agonist ADU-S100 can significantly improve the antitumor immunity of the CS-pDKK1 nanoparticle vaccine in MM,and this vaccine strategy provides a potential treatment approach for MM.