Objective To evaluate the effects and safety of uterine artery embolization for uterine leiomyoma. Methods Total of 185 patients with uterine leiomyoma were treated by UAE. They were followed for one to 6 years to observe the changes of leiomyoma size and improvement in clinical symptoms. Ovarian function was evaluated in 44 cases. Results Bilateral embolization of uterine arteries was performed in 185 patients. Follow-up of 1 ～6 years for 292 leiomyoma indicated that one to 9 months after embolization, shrinkage of leiomyoma size was the most significant factor. One year after embolization, leiomyoma sizes decreased a little. Shrinkage of submucous leiomyoma was more significant than that of intratumoral one, and the latter was more significant than subserous one. Shrinkage of leiomyoma with large size ( volume ≥ 150cm~3) was less than that of small one. Menorrhagia, anemia and pressure symptoms were all resolved. There was no significant difference between pre- and post embolization ovarian hormone level. Conclusions The significant reduction in leiomyoma volume and resolution of clinical symptoms confirmed that the treatment validity of symptomatic leiomyomas by UAE. UAE is an effective therapeutic procedure which has no adverse effect on the ovarian function.

Objective To investigate the impact of injection current (IC), injection voltage (IV), and pulse forming network (PFN) on energy (depth ratio D20/D10) and profiles of helical tomotherapy, and to improve the quality control for the stability of beam characteristics.Methods The energy and profiles were measured by ion chamber and TomoDose at different values of IC, IV, and PFN, the relationship between the energy and various parameters was evaluated by Pearson correlation analysis, and the changes in profiles were evaluated by comparative analysis.Results The energy had no correlation with IV and PFN values (P>0.05), but had a strong correlation with IC value (P=0.007), which showed a downward trend with the increase in IC.For the profiles in the x direction:(1) in the main beam region (-200 to 200 mm), the shoulder area of the profiles increased regularly with the increase in IC.There were no significant changes for the profiles when the IV values ranged from 6.42 V to 6.54 V, and the shoulder area of the profiles reached the highest point with IV=6.60 V, then decreased with further increase in IV.The shoulder area of the profiles decreased regularly with the increase in PFN.(2) In the penumbral region (±200 mm outside), all the three parameters had no effect on the profiles.For the profiles in the y direction:(1) in the main beam region (-20 to 20 mm), the profiles showed an upward trend in the area with an off-axis distance less than 16 mm when IC values were 5.40 V and 5.46 V, and showed an upward trend in the area with an off-axis distance less than 16 mm.But on the whole, the shoulder area of the profiles increased with the increase in IC, and was not affected by IV and PFN.(2) In the penumbral region (±20 mm outside), the profiles decreased regularly with the increase in IV, and was not affected by IC and PFN.IC had the highest influence on the profiles in the main beam region, followed by PFN and IV.Only IV had impact on the profiles in the penumbral region.Conclusions When the energy needs to be adjusted, the IC value should be given a priority, and PFN should be taken as a supplementary factor.When the profile needs to be adjusted, the IC value should be given a priority, and IV should be used as an auxiliary factor in the main beam region.But in the penumbral region, adjustment of parameters is only related to the profiles in y direction, so the IV value should be adjusted.This study has a guiding role in the quality control of energy and profiles, which can reduce the blindness of quality control, thus saving the time.

Objective To quantitatively investigate the image quality and dose calculation accuracy of megavoltage computed tomography (CT) in helical tomotherapy.Methods The megavoltage CT was used to scan the Cheese phantom,and the geometric accuracy of images,noise,image uniformity,spatial resolution,density-CT value conversion,and dose calculation accuracy were analyzed and compared with conventional kilovoltage CT.Results The geometric accuracy of megavoltage CT images was within 2 mm in three directions.The megavoltage CT was inferior to kilovoltage CT in terms of image noise,uniformity,and spatial resolution.The dose-volume histogram (DVH) in dose reconstruction based on CT images was well consistent with DVH in the kilovohage CT plan.Conclusions The megavoltage CT can obtain images with accurate geometric dimensions and has a low imaging dose and accurate dose calculation,which meets clinical requirements.

Objective To study the CT number and noise of HT MVCT on different dose rate and scanning thickness.Methods The CT number of different relative electron density were measured in the MVCT image of Cheesephantom with tissue substitute plugs scanned with different dose rate and slice thickness.The physical density corresponding to the CT number was plotted as the image value to density table (IVDT).The noise was measured in the MVCT image of Cheesephantom with solid water plugs scanned with different dose rate and slice thickness.Results There was a significant different of the CT number of the plugs with different dose rates (P =0.000),it shows a positive correlation between the varied CT number and density (R2 =0.846),there is larger impact on the high density number.There was still a significant effect on the noise with different dose rate (P =0.000 density),the noise increase as the dose rate decrease.There was no significant effect on IVDT (P =1.000) and noise (P =0.667) with different slice thickness.Conclusions The CT number and the noise vary with the dose rate,the QA of MVCT should be performed regularly to assure the quality of image and the accuracy of dose calculating on MVCT in adaptive.

Objective To analyze geometrical uncertainties of the target and provide the margin enlarging from clinic target volume (CTV) to planning target volume (PTV) with HT.Methods Analysis set-up data of 220 cases include 97 cases of head and neck,45 cases of chest and 78 cases of abdomen and pelvic,calculating the systematic error (Σ) and the random error (σ) in the three-dimension and check whether the set-up data accord with the normal distribution or not,then acquire the values expand in the three directions based on formula 2.0Σ + 0.7σandμ ± 2.58σ.Results The systematic error (Σ) and random error (σ) of head and neck,the chest and abdomen and pelvic were (0.7-1.9 mm,1.1-1.4 mm),(0.8-4.2 mm,1.5-3.2 mm),(1.1-4.1 mm,1.8-4.1 mm),respectively,and the margin that expand in the direction of x,y,z were (5.2,6.5,7.7 mum),(7.5,16.2,10.3 mm),(7.6,17.1,15.7 mm),respectively.Conclusions The curative effect of this task need prove with a large sample during HT,but other should establish data of margin by yourself.

Objective To investigate the factors of effecting with yindex analysis of delivery for helical tomotherapy (HT).Methods Measuring γindex with the ArcCheck device for introduced errors in HT.The errors include setup errors in three-dimensional,the gantry angle error,calculating the dose in the phantom,low dose rate.All the results were compared with the 3％/3 mm and 2％/2 mm criteria.The effect of the accuracy in the application of kilovoltage computed tomography (KVCT) and mega-voltage computed tomography (MVCT) images in HT was also analyzed.Paired-t test method was used for difference compared.Results When the errors were introduced to the HT,theγpassing rate of left-right,superior-inferior,anterior-posterior direction dropped 2.7％,7.2％,3.6％ under the 3％/3 mm criteria (P =0.002,0.022,0.007),with 4.6％,15.7 ％,7.6％ under the 2％/2 mm criteria (P =0.001,0.003,0.002) respectively.There was no statistical significance for theγpassing between scanning the ArcCheek phantom with the KVCT and MVCT under the 3％/3 mm and 2％/2 mm criteria (98.6％ vs 98.7％,P =0.859 and 92.7％ vs 92.8％,P =0.984).Conclusions The errors of the setup position and machine paraments can lead to the dose delivery errors in HT,the quality accurance of machine and plan should be enhanced to minimize the dose errors.The results also showed that there is no difference of KVCT and MVCT image on the delivery of HT.

Objective:To compare the leaf open time (LOT) parameters and γ passing rates between the 4.0.4 and 4.2.3 helix Tomotherapy planning systems and evaluate the improvement.Methods:Retrospective comparison of the treatment plans of 345 cases selected by 4.0.4 and 4.2.3 versions was performed. The Machine Specific Sinogram of each plan was extracted from the archived plan file to calculate the LOT. The evaluated LOT parameters included the projection time, the maximum LOT, the mean non-zeros time, the time difference between the projection time and the maximum LOT, the relative count of leaves with LOT greater than maximum LOT minus 5 ms, the relative count of leaves with LOT lower than 100 ms and the beam on time. The γ passing rate (criteria: 3 mm/3%, 10% threshold and global error) and the LOT parameters between two version systems were evaluated with the independent t-test. The relationship between the LOT parameters and γ passing rate was analyzed by the multiple linear regression method. Results:The γ passing rate of the Ver 4.0.4 system was 97.86%, significantly lower than 98.6% of the Ver 4.2.3 system ( P<0.001). The time gap between the projection time and the maximum LOT of the Ver 4.2.3 system was significantly less than that of the Ver 4.0.4 system (1 ms vs. 11 ms, P<0.001). For the Ver 4.0.4 system, the multiple linear regression method showed that the maximum LOT ratio and the beam on time were negatively correlated with the γ passing rate (both P<0.001). However, for the Ver 4.2.3 system, only the beam on time showed a negative correlation with the γ passing rate ( P<0.001). Conclusion:The γ passing rate of the Ver 4.2.3 system is significantly higher than that of the Ver 4.0.4 system. The decrease of γ passing rate caused by the leaves near the maximum LOT is properly resolved in the new version system.

Objective:To evaluate the sensitivity of the ArcCheck dosimetry system in detecting the leaf open time errors during the center and off-center helical tomotheray delivery quality assurance (DQA).Methods:Nine nasopharyngeal carcinoma (NPC) patients were selected in this study. Two DQA plans were created for each patient: the" center" plan was created by moving the image of the ArcCheck phantom to place the high dose region on the phantom center and the " off-center" plan was created by offsetting the phantom and putting several diodes through a higher does region. Leaf open time errors of 2, 4, 6, 8 and 10 ms were introduced to the Sinogram which was modified using Matlab. Each intentional error plan and original (no error) plan for each patient were measured using both " center" and " off-center" DQA methods, the γ analysis was performed to evaluate the DQA results. The different dose and distance error criteria of 3%/3 mm, 3%/2 mm and 2%/2 mm were selected, and different thresholds of 5%, 10% and 15% were selected for γ analysis. The gradient and the minimum detectable error approach were taken to quantitatively analyze the sensitivity. The correlation between different dose distance error criteria and different thresholds was also evaluated by Pearson correlation analysis. Results:The absolute value of γ gradient of the " center" DQA plans were larger than those of the " off-center" plans in all different γ criteria (all P<0.05). The stricter the γ criteria were adopted, the more sensitive DQA results of leaf open time error were obtained. The minimum detectable error was 2 ms in all different γ criteria for the " center" DQA plan. The minimum error detectability of the " off-center" DQA plan was weaker than that of the " center" DQA plan. The γ passing rates of three different dose distance error criteria were significantly strongly correlated for the " center" DQA plan ( R2>0.9). For the " off-center " DQA plan, only the 3%/3 mm and 3%/2 mm criteria were significantly strongly correlated ( R2>0.9). Significant strong correlation was observed in the γ passing rate at different thresholds between the " off-center" and " center" DQA plans. Conclusions:The " center" DQA plan method is more sensitive than the " off-center" DQA plan method in all γ criteria, and the γ passing rates in different γ criteria are strongly correlated for the " center" DQA plan. The " center" DQA plan method is recommended.

Objective To evaluate the dosimetric characteristics of the TomoDose diode and its application in detecting the couch velocity and assessing the beam Profile stability for convenient and efficient quality control of Tomotherapy.Methods Fundamental properties of the TomoDose detector,such as dose linearity,dose per pulse dependence,directional dependence and field size dependence were tested by the water-equivalent phantom and the results were statistically compared with those measured by the ion-chamber (0.057 cm3,A 1SL).Five different couch velocities with a time interval of 0.0005 s were designed to test the sensitivity of TomoDose for detecting the couch velocity,and then the clinical data of 7 patients with different couch velocities were selected to verify the test accuracy.The beam profile of three different jaws of 1.0,2.5 and 5.0 cm were measured using TomoDose with water-equivalent phantom in the x and y directions under the same conditions as water tank with an underwater depth of 15,50,100,150 and 200 mm,respectively.The Profile data obtained by water tank and TomoDose were evaluated using the Gamma (γ) evaluation method with the 2％/1 mm criterion.Results The dose linearity of the TomoDose and ion chamber was in a linear pattern within the beam-on-time ≤ 30 s.The difference between the TomoDose and ion chamber was less than 2％ for the dose per pulse dependence,and the response trends of them were consistent.TomoDose showed angular response dependence with a maximum difference of 2.53％ for the gantry angle of ±60°.For the field size dependence,the response difference between the TomoDose and ion chamber was increased with the decreasing field size when the Jaw was 5.0 cm,and the maximum deviation was 0.78％ when the field size was 5.0 cm×2.5 cm.TomoDose could detect the couch distance error of 0.5 mm,and determine the couch velocity deviation of＜ 0.6％.For the Profile stability testing:In the x direction,there was always γ＜1 at the underwater depth of 15 mm for all values of Jaw;when the underwater depth was not 15 mm,there was always γ＜ 1 in the main beam region (off-axis distance＜ 200 mm),whereas in the penumbra region (off-axis distance＞ 200 mm),the value of γ was larger and even with γ＞ l.In the y direction,all comparison results of Profile under three field width demonstrated that γ index was larger on the edge of beam,whereas γ＜1 was found in all cases.Conclusions TomoDose is suitable f or the quality control of Tomotherapy,which can accurately measure the couch velocity,precisely monitor the stability of beam Profile of Tomotherapy and complete the quality control process in a convenient and efficient manner.

Astragalosides are the main active constituents of traditional Chinese medicine Huang-Qi, of which cycloastragenol-type glycosides are the most typical and major bioactive compounds. This kind of compounds exhibit various biological functions including cardiovascular protective, neuroprotective, etc. Owing to the limitations of natural sources and the difficulties encountered in chemical synthesis, re-engineering of biosynthetic machinery will offer an alternative and promising approach to producing astragalosides. However, the biosynthetic pathway for astragalosides remains elusive due to their complex structures and numerous reaction types and steps. Herein, guided by transcriptome and phylogenetic analyses, a cycloartenol synthase and four glycosyltransferases catalyzing the committed steps in the biosynthesis of such bioactive astragalosides were functionally characterized from Astragalus membranaceus. AmCAS1, the first reported cycloartenol synthase from Astragalus genus, is capable of catalyzing the formation of cycloartenol; AmUGT15, AmUGT14, AmUGT13, and AmUGT7 are four glycosyltransferases biochemically characterized to catalyze 3-O-xylosylation, 3-O-glucosylation, 25-O-glucosylation/O-xylosylation and 2'-O-glucosylation of cycloastragenol glycosides, respectively. These findings not only clarified the crucial enzymes for the biosynthesis and the molecular basis for the structural diversity of astragalosides in Astragalus plants, also paved the way for further completely deciphering the biosynthetic pathway and constructing an artificial pathway for their efficient production.