Objective:To discuss application of large aperture 16 row spiral CT in radiotherapy simulation positioning. Methods: To apply CT simulation positioning with large aperture 16 row spiral CT for the breast tangential field by early breast cancer after breast conserving surgery and radical radiotherapy. Compare CT-simulation and X-ray conventional positioning technique and Compare large aperture 16 row spiral CT and single row spiral CT image. Results: The application of large aperture 16 row spiral CT avoided the error because of body limited. Large aperture 16 row spiral CT simulation position validation error is superior to X-ray positioning. Its image quality is better than that of single row spiral CT. Conclusion:The application of large aperture 16 row spiral CT make simulation positioning more accurate, planned and treatment more accurate, it can provide guarantee of accurate simulation positioning for accurate plan and treatment.

Objective To analyze the influence of tumor volume change on intensity modulated radiotherapy(IMRT)for nasopharyngeal carcinoma by analyzing the repeated CT simulation.Methods Twenty nasopharyngeal carcinoma patients undergoing IMRT from July 2011 to November 2012 were selected in the study.The first CT simulation was conducted prior to radiotherapy,and the repeated CT simulation was finished after radiotherapy of 30 Gy.The first and the repeated CT images were fused in treatment planning system and GTV volume shrink rate was calculated.The original plan was used to recalculate the dose distribution on repeated CT.The dose volume histogram was used to calculate the dose difference of organs at risk including the brain stem and spinal cord.Results Compared with the first CT,GTV volume shrink rate of the repeated CT simulation was 28.7％,the maximum dose,1 cm3 volume and the average dose percentage of the brain stem and spinal cord were increased(t=0.83-3.17,P＜0.05).Conclusions GTV volume shrinked significantly after radiotherapy of 30 Gy in IMRT for nasopharyngeal carcinoma.The dose of the organs at risk increased accordingly.

Objective To compare the errors of final isocenter marking method and reference point marking method for CT simulation positioning in intensity-modulated radiotherapy (IMRT).Methods From 2009 to 2012,327 patients with head and neck cancer for IMRT underwent CT simulation positioning using the Philips Brilliance CT Big Bore scanner and Philips Tumor LOC workstation and were divided into final isocenter marking group (n =208) and reference point marking group (n =119) according to positioning methods.Target volume delineation and treatment plan design were performed on the Varian Eclipse treatment planning system (TPS).Before treatment,kilovoltage cone-beam CT scans and registration were performed with the Varian EX on-board imager system to obtain beam position errors in the right-left (RL),superior-inferior (SI),and anterior-posterior (AP) directions,and then comparisons of errors between the two groups were made by independent-samples t test.Finally,the TPS was used to measure the changes in the doses to the organs at risk after moving isocenters in the RL,SI,and AP directions among 5 patients with nasopharyngeal carcinoma.Results The mean beam position errors in the three directions were less in the final isocenter marking group than in the reference point marking group (P =0.02,0.01,0.03).After moving isocenters in the three directions,the target dose was reduced and the dose to the normal tissue around the target tumor was increased significantly.The error in the AP direction had the maximum influence on the spinal cord and brainstem.Conclusions Final isocenter marking method leads to less beam position error than reference point marking method in CT simulation positioning.Small isocenter motion can cause large changes in the doses to the organs at risk.

Adult ; Aged ; Arthritis, Rheumatoid ; complications ; Female ; Humans ; Intracranial Thrombosis ; complications ; Male ; Middle Aged ; Pulmonary Embolism ; complications ; Venous Thrombosis ; complications

Objective To investigate the significance of thyroid function screening in high-risk pregnant women with gestational diabetes (GDM) in early pregnancy.Methods A total of 194 cases with GDM were selected as our subjects.The patients were divided into group A(three normal items,a total of 109 cases),group B (one abnormal item,a total of 57 cases) and group C (two abnormal items,a total of 28 cases).The levels of serum anti-thyroglobulin antibody (TGAb),anti-thyroid peroxidase antibody (TPOAb),serum three triiodothyronine(TT3),thyroxine (TT4),free three triiodothyronine (FT3),free thyroxine (FT4) and thyroidstimulating hormone (TSH) were screened.Results TSH levels in group A was (1.45 ± 0.43) mU/L,significantly lower than in group B and group C((1.77±0.53),(1.89±0.74) mU/L).FT4 levels in group A was (11.62±0.98) nmol/L,significantly higher in group B and group C((10.23±0.75),(9.87±0.88) nmol/L)).Proportion of TPOAb,TGAb positive in group A were 9.17％(10/109) and 21.05％(12/57),significantly lower than that of group B and group C((28.57％(8/28) and 3.67％(4/109),7.02％(5/57) and 17.86％(5/28)).And the differences were significant (P＜ 0.05).And TPOAb + TGAb in group A was 0.92％(1/109),significantly lower than that of group B and group C(7.02％ (4/57),17.86％ (5/28);P ＜0.05).Conclusion The importance of screening thyroid function in early pregnancy in women at high risk for gestational diabetes is worthy of clinical promotion.

Objective To discuss the X-knife radiosurgery (XKS) in the treatment of brain metastasis of lung carcinoma. Methods A total of 100 patients with similar prognostic factors were divided into two groups with 50 patients in each group, receiving either whole-brain radiotherapy alone (30~40 Gy/3~4 weeks) (Radiotherapy Group) or XKS combined with radiotherapy (Combination Group). In the Combination Group, 27 patients received XKS with single fraction of radiation, with a median prescription dose of 14.2 Gy, and the other 23 patients received multiple fractions of radiation (5~10 Gy/f, 3 times weekly), with a total dose of 15~30 Gy. Results In the Combination Group and the Radiotherapy Group, the median survival time was 16.4 and 10 months, respectively (P=0.0064), the 2-year local tumor control rate was 88% (44/50) and 44% (22/50), respectively (?2=21.569,P=0.000), and the effective rate under CT or MRI scanning at 1~3 months after treatment was 87.5% (35/40) and 52.2% (24/46), respectively (?2=16.497,P=0.001). An analysis on the cause of death showed that 11.9% of patients (5/42) in the Combination Group died from brain metastasis, which was significantly lower than that in the Radiotherapy Group (55.6%, 25/45) (?2=25.908,P=0.000). The incidence of complications was not significantly different between the Combination Group (8%, 4/50) and the Radiotherapy Group (4%, 2/50) (?2=0.709,P=0.400). Conclusions Combined use of X-knife radiosurgery and routine radiotherapy has better therapeutic effects than radiotherapy alone for treating brain metastatic tumor.

Background The pathogenesis of dry eye is complicated,hormone level is thought to be one of impact factors in the development of dry eye.The regulation of the synthesis process of metalloproteinases(MMPs) in tissue has been reported.However,the effects of hormone on expression of MMP-2 in lachrymal gland is not clear.Objective This study was to investigate the effects of estrogen and androgen on the expression of MMP-2 in lachrymal gland in ovariectomized rats,and explore the role of MMP-2 in dry eye.Methods Sixty-four 3-monthold clean female Wistar rats were randomized into control group(8 rats),sham operation group(8 rats)and experiment group(48 rats).Ovariectomy(OVX) was performed on the rats of experiment group,and only fat tissue of abdominal cavity was cut off in the rats of the sham operation group.After 5 months of OVX,the experimental rats were subdivided into model control group,vehicle group,estrogen and androgen systemic or topical utilization groups and 8 rats for each group.Six weeks after administration of the drugs,the lachrymal gland was obtained.The expression of MMP-2 mRNA in the lachrymal gland was detected by reverse transcription PCR(RT-PCR),β-actin mRNA was used as an internal control,and the expression of MMP-2 protein was detected by Western blot,GAPDH was used as protein loading control.The use and care of the rats complied with the ARVO Statement.Results The expression of MMP-2 mRNA was strongest in the systemic estrogen group and was weakest in the systemic androgen utilization group.A significant difference in the MMP-2 mRNA expression was found among the 8 groups(F=18.60,P＜0.01),and the MMP-2 mRNA was significantly higher in the model group than that of the normal control group(0.66±0.10vs.0.47±0.10)(q=3.01,P＜0.05).In addition,the MMP-2 mRNA was significantly higher in the systemic estrogen group compared with the model group (0.83 ±0.10 vs.0.66-0.10) (q =2.79,P＜0.05) ; while the expression of MMP-2 mRNA was significantly declined in the systemic androgen group in comparison with the model group(0.12±0.04 vs.0.66±0.10)(q=11.41,P＜0.01).The MMP-2 protein presented with a strongest expression in the systemic estrogen utilization group and a weakest expression in the systemic androgen utilization groups.The expression level of the MMP-2 protein in the lachrymal gland was significantly different among the 8 groups(F =7.28,P＜0.01).The MMP-2 in the model group was significantly higher than that of the normal group(0.55±0.13 vs.0.38±0.08) (q =2.39,P＜0.05),and that in the systemic estrogen group was increased in comparison with the model group(0.69±0.12 vs.0.55±0.13) (q =1.85,P＜0.05).However,the MMP-2 in the systemic androgen group was significantly lowed in comparison with the model group(0.27±0.07 vs.0.55±0.13) (q =4.32,P＜0.01).Conclusions Estrogen may up-regulate the expression of MMP-2 in lachrymal gland,but the effect of androgen is opposite.Hormone level may play an important role in the regulation of the function of lachrymal gland.

Acquired Immunodeficiency Syndrome ; immunology ; HIV Infections ; immunology ; Humans ; Medicine, Chinese Traditional ; T-Lymphocytes ; physiology

Adolescent ; Female ; Humans ; Lymphoma, Extranodal NK-T-Cell ; pathology ; therapy ; Neoplasm Staging ; Nose ; pathology

Objective To evaluate the effect of dose-rate and leaf position tolerance on the point dose in step-and-shoot intensity-modulated radiotherapy(IMRT). Methods IMRT plans of 2 prostate cancer patients were selected and recalculated for a water phantom.An ionization chamber was used to measure the dose of some points in the phantom at five nominal dose-rates:100 MU/min,200 MU/min,300 MU/min,400 MU/min and 500 MU/min.It was necessary to adiust the position of the water phantom to locate the ionization chamber in region where the dose gradient was very low in order to minimize the effect of dose gradient on the measured results.When measuring the effect of leaf position tolerance on point dose,the dose-rate was kept constant and the values of tolerance were 1 mm,2 mm,3 mm and 4 mm.This work was conducted on a Varian 23EX equipped with a Millennium 120-leaf multi-leat collimator(MLC).The treatment planning system was Varian Eclipse. Results As the dose-rate increased,the error between the measured dose and the calculated dose also enlarged.The difference between the maximum and the minimum was 1.2%.When MLC control system was working normally,tlle effect of leaf position tolerance on the measured point dose was very little and negligible. Conclusions The dose-rate must be selected suitably to ensure that the delivery can be finished in a short time with the radiobiological effect taking into account.It should be noted that the error between the measured dose and the calculated dose increases with the trend of inereasing more rapidly at higher dose rates.The value of leaf position tolerance should not be set too large,in order to minimize the difference between the measured dose and the planned dose in the region of steep gradient and find as early as possible when the multi-leaf collimator control system performs improperly.