Objective To evaluate the improvement of cone beam CT (CBCT) image quality by using bewtie filter (F_1) and water calibration. Methods First the multi-level gain calibration of the detector panel with the method of Cal_2 calibration was performed, and the CT images of CATPHAN503 with F_0 and bowtic filter were collected, respectively. Then the detector panel using water calibration kit was calibrated, and images were acquired again. Finally, the change of image quality after using F_1 and (or) water calibration method was observed. The observed indexes included low contrast visibility, spatial uniformity, ring artifact, spatial resolution and geometric accuracy. Results Comparing with the traditional combination of F_0 filter and Cal_2 calibration, the combination of bowtie filter F_1 and water calibration improves low contrast visibility by 13.71%, and spatial uniformity by 54. 42%. Water calibration removes ring artifacts effectively. However, none of them improves spatial resolution and geometric accuracy. Conclusions The combination of F_1 and water calibration improves CBCT image quality effectively. This improvement is aid to the registration of CBCT images and localization images.

Objective To evaluate the value of CT perfusion imaging (CTPI) in the diagnosis of hepatocellular carcinoma (HCC). Method CTPI was carried out on 21 patients with 26 lesions to obtain the following perfusion parameters: hepatic blood flow (HBF), hepatic blood volume (HBV),mean transit time (MTT), permeability surface area product (PS), and hepatic arterial fraction (HAF). The parameters from the lesion and non-lesion areas were compared. In addition, serum AFP was measured in the HCC patients and a linear correlation analysis between the alpha-fetoprotein (AFP) level and the CTPI parameters was performed. Result CTPI failed in 3 patients with 3 lesions and was successful in 18 patients with 23 lesions which included 18 HCC, 4 hemangioma of the liver,and 1 hepatic focal nodular hyperplasia (FNH). On comparison of the HCC parameters in the lesion and non-lesion areas, significant differences were found in the HAF which was 4.11 times higher in the lesion than the non-lesion areas, while the MTT and PS were significantly lower. There was no significant difference in the HBF and HBV. Correlation between the serum AFP level and the CTPI parameters of the HCC lesion was insignificant. The differences of all the parameters between the lesion and the non-lesion in hemangioma were similar to those in HCC, except for a higher HBF in the lesion than in HCC. There was no significant difference between the parameters of FNH and the non-nodular part of the liver. Conclusion CTPI played an important role in the diagnosis and differential diagnosis of HCC, especially when the AFP was negative and/or the imaging manifestation was atypical on contrast CT.

Objective This study was to assess the three-dimensional gross tumor volume(GTV)motion of lung cancer caused by respiration using four-dimensional computed tomography(4DCT),and to analyze the influenee factors.Methotis Four-DCT scans of 22 lung focuses in 21 patients with lung cancer were analyzed.The gross tumor volume was contoured in all 10 respiration phases of 4DCT scans.The changes in volume of GTV,the 3D motion of the centroid,boundary of GTV and the 3D spatial motion vectors were calculated and the irdluenee factors were analyzed.Results The average change in volume of GTV was+14.3%(0.2%.42.5%)/-8.4%(0.4%-38.6%),the average movement amplitude of GTV centroid and GTV boundary were(0.18±0.12)cm,(0.20±0.16)cm,(0.53±0.59)cm and(0.42±0.23)cm,(0.41±0.22)cm,(0.57±0.70)cm in medio-lateral,vertro-dorsal,cranio-caudal(CC) direction,respectively.The CC movement was larger than other directions(Z=-2.12,P=0.034;Z:-2.10,P=0.035),and no significant difference was observed in 3D motion of GTV boundary(Z=-0.81.P=0.417;Z=-0.86,0.391).The CC motion of GTV eentroid in lower lobe was larger than that in upper lobe[(0.87±0.64)and(0.35±0.49)cm,(t=-2.12,P=0.047)],and no significant difference was found in other directions[(0.23±0.10)and(0.19±0.18)em(t=-0.49,P=0.629),(0.21±0.13)and(0.17±0.11)cm(t=0.76,P=0.460)].There was no correlation of the 3D movement and 3D spatial motion vector of GTV to the volume of GTV(r=-0.306,-0.062,-0.279,-0.300;P=0.189,0.796.0.234,0.199).Conclusions GTV motion of patients with lung cancer is individual,the CC movement is the moat obvious,using 4DCT to assess is comparatively accurate.The motion amplitude of lower lobe focuses is larger.No significant correlation of the GTV motion to the volume was observed.Larger sample study is needed to analyze the influence of adjacency to the GTV motion.

Objective To find out present condition and differences in implementation of clinical pathways in hospitals of in China.Methods "Clinical pathway" was entered as a keyword to search in PubMed NCBI Chinese Science and Technology Periodical Database for related literatures in China from 1999 to 2009,analyzing the general implementations of clinical pathways in hospitals in different areas using the SPSS12.0 software.Results A total of 1051 relevant literatures were found.Through data analysis of these literature,differences of implementation of clinical pathways were found for 162 hospitals of different areas.It was found that the differences of total diseases among China's East,West and Central areas are significant statically.Diseases of implementation per hospital in the Central average 16.8,those in the East 8 types,while those for the West 4.4.Tertiary hospitals account for 70% as the main force of clinical pathway implementation,with diseases of implementation up to 13.7,while that under tertiary level down to 2.8.Conclusions Implementation of clinical pathways varies significantly among hospitals in different areas in China.In the process of implementing clinical pathway,appropriate management strategies should be developed according to actual situation in different hospitals in light of policies,hospital management and patient considerations.

OBJECTIVE A surveillance study was performed for nosocomial infections in order to investigate the change in antimicrobial resistance of Klebsiella pneumoniae,especially the strains isolated from 1999 to 2004.METHODS K-B test was used for the antibiotics susceptibility test and the results were read based on National Committee for Clinical Laboratory Standards(NCCLS) of the USA.The situation of ESBLs-producing strains of K.pneumoniae was investigated.RESULTS Totally 326 K.pneumoniae strains showed the highest susceptibility to imipenem.Ceftazidime,cefepime,and cefoperazone/sulbactam also showed excellent activity against K.pneumoniae.The prevalence of ESBLs from 326 strains was 20.2%.CONCLUSIONS It is important to study the drug resistance in nosocomial infections by K.pneumoniae.

OBJECTIVETo investigate the dosimetric benefit of 4D-CT in the planning target volume (PTV) definition process compared with conventional PTV definition using general margin in radiotherapy of lung cancer.

METHODSA set of 4D-CT images and multiphase helical CT scans were obtained in 10 patients with lung cancer. The radiotherapeutic plans based on PTV determined by 4D-CT and in addition of general margin were performed, respectively. The 3D motion of the centroid of GTV and the 3D spatial motion vectors were calculated. The differences of the two kinds of PTVs, mean lung dose (MLD), V5,V10,V15,V20 of total lung, mean heart dose (MHD), V30 and V40 of heart, D99 and D95 were compared, and the correlation between them and the 3D spatial motion vector was analyzed.

RESULTSThe PTV4D in eight patients were smaller than PTVconv, with a mean reduction of (13.0 ± 8.0)% (P = 0.018). In other two patients, whose respiration motion was great, PTV4D was larger than PTVconv. The mean 3D spatial motion vector of GTV centroid was (0.78 ± 0.72)cm. By using 4D-CT, the mean reduction of MLD was (8.6 ± 9.9)% (P = 0.037). V5, V10, V15, V20 of total lung were decreased averagely by (7.2 ± 10.5)%, (5.5 ± 8.9)%, (6.5 ± 8.4)% and (5.7 ± 7.4)%, respectively (P < 0.05 for all). There was a significant positive correlation between PTV4D/PTVconv and the 3D spatial motion vector of the GTV centroid (P = 0.008). A significant inverse correlation was found between D994D/D99conv and the 3D spatial motion vector of the GTV centroid (P = 0.002). D994D/D99conv, (MLDconv-MLD4D) /MLDconv, total lung (V5conv-V54D)/V5conv, total lung (V10conv-V104D)/V10conv, (MHDconv-MHD4D)/MHDconv, heart (V30conv-V304D)/V30conv were inversely correlated with PTV4D/PTVconv (P < 0.05 for all).

CONCLUSIONS4D-CT can be used to evaluate the respiration motion of lung tumor accurately. The 4D-CT-based PTV definition and radiotherapeutic planing can reduce the volume of PTV in patients with small respiration motion, increase the intra-target dose, and decrease the dose of normal tissue sequentially. For patients with large respiration motion, especially those more than 1.5-2 cm, this method can avoid target miss, meanwhile, not increase the dose of normal tissue significantly.

Four-Dimensional Computed Tomography ; methods ; Humans ; Lung ; physiopathology ; Lung Neoplasms ; radiotherapy ; Movement ; Radiometry ; Radiotherapy Planning, Computer-Assisted ; methods ; Respiration ; Tomography, X-Ray Computed ; methods

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.

MicroRNAs (miRNAs) are small, non-coding RNAs that function as post-transcriptional regulators of gene expression. The deregulated expression of miRNAs is associated with a variety of diseases, including breast cancer. In the present study, we found that miR-495 was markedly up-regulated in clinical breast cancer samples by quantitative real time-PCR (qRT-PCR). Junctional adhesion molecule A (JAM-A) was predicted to be a potential target of miR-495 by bioinformatics analysis and was subsequently verified by luciferase assay and Western blotting. JAM-A was found to be negatively correlated with the migration of breast cancer cells through loss-of-function and gain-of-function assays, and the inhibition of JAM-A by miR-495 promoted the migration of MCF-7 and MDA-MB-231 cells. Furthermore, overexpression of JAM-A could restore miR-495-induced breast cancer cell migration. Taken together, our findings suggest that miR-495 could facilitate breast cancer progression through the repression of JAM-A, making this miRNA a potential therapeutic target.
3' Untranslated Regions ; genetics ; Adult ; Aged ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Adhesion Molecules ; genetics ; metabolism ; Cell Line, Tumor ; Cell Movement ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; Humans ; MCF-7 Cells ; MicroRNAs ; genetics ; Middle Aged ; RNA Interference ; Receptors, Cell Surface ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

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 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.