RESUMEN
Objective:To evaluate the cumulative dose of the target volume and organs at risk (OARs) in intensity-modulated radiation therapy (IMRT) for large volume non-small cell lung cancer (NSCLC) based on rigid and deformation registration methods. The dosimetric changes between the initial and second treatment plans were compared.Methods:Thirty patients treated with IMRT for large volume NSCLC with twice 4DCT scans acquired before radiotherapy and after 20 fractions of radiotherapy were recruited. The initial treatment plan (Plan 1) based on the average density projection CT (CT 1-avg) of the first 4DCT images and the second treatment plan (Plan 2) based on the average density projection CT (CT 2-avg) of the second 4DCT images were calculated. Then, the dose distributions of Plan 1 and Plan 2 were accumulated based on rigid and deformation registration methods to obtain Planrig and Plandef, respectively. Finally, the volume changes of gross tumor volume (GTV) and OARs between two CT scans were compared. The dose-volume parameters between Plan 1 and other plans (including Plan 2, Planrig and Plandef) were also statistically compared. Results:Compared with the initial CT scan, the mean volume of GTV and heart on the second CT was decreased by 44.2% and 5.5%, respectively, while the mean volume of ipsilateral lung, contralateral lung and total lung was increased by 5.2%, 6.2% and 5.8%, respectively (all P<0.05). Compared with Plan 1, the D 95%, D 98% and V 100% of target volume IGTV (GTV fusion of 10 4DCT phases) and PTV in Plan 2 did not significantly change (all P>0.05), and those in Planrig and Plandef were decreased (all P<0.05). The dose-volume parameters of spinal-cord, heart, ipsilateral lung and total lung in Plan 2, Planrig and Plandef were significantly lower than those in Plan 1(all P<0.05). Among them, the V 30Gy and D mean of heart were decreased by 27.3%, 16.5%, 15.3% and 15.2%, 6.6%, 5.6%, respectively. The V 20Gy and D mean of total lung were decreased by 15.6%, 4.5%, 3.7% and 15.7%, 6.2%, 5.1%, respectively. Some dose-volume parameters (including D 95% and D 98% of target volume, V 40Gy of heart, V 20Gy and D mean of the ipsilateral lung and the total lung) of Plandef were higher than those in Planrig (all P<0.05). The Dice similarity coefficients (DSCs) of OARs after deformation registration were significantly higher than those after rigid registration ( P<0.05). Conclusions:The dose-volume parameters of OARs significantly differ between Plan 1 and Plan 2. Hence, all these parameters have a large degree of deviation in predicting radiation-induced injury of OARs. Nevertheless, the dose-volume parameters obtained by deformation registration can enhance the prediction accuracy.
RESUMEN
Objective:To provide a feasible method for the evaluation of cardiac function based on cardiac gated 4DCT, the radiomics technology combined with enhanced ECG gated 4DCT images were used to quantitatively analyze the changes of left ventricular CT radiomics characteristics in cardiac cycle.Methods:The enhanced ECG 4DCT images of 14 patients were reconstructed at intervals of 5% of cardiac cycle. The left ventricular muscle (LVM) and the contrast agent well filled area of left ventricular were delineated with a 13 mm diameter sphere (Cardiac Region of Interest, cardiac ROI) in a single phase. 3Dslicer software was used to extract 92 features of all the sketches, analyze the distribution of CT values on the cardiac ROI and LVM, and preliminarily screen the stable features based on the cardiac ROI (one-way ANOVA). The stable features were used to further screen LVM (one-way ANOVA) to get the difference features. Wilcoxon rank sum test was used to analyze the change of characteristics with heartbeat in the heartbeat cycle.Results:In the heartbeat cycle the mean CT values of cardiac cavity ROI in cardiac cavity changed less than that in LVM, with the change rates of 9.23% and 17.88%, respectively. There were 36 stable features with no significant difference in cardiac cavity ROI ( P>0.05). 20 of them were statistically significant ( F=1.641-6.206, P<0.05), and the average change rate was 98.63%, such as median (-103.96%) and mean (123.67%) of the first order matrix, gray level non uniformity (99.81%) of GLDM matrix and other changes reached more than 99%. The differences between the maximum and minimum values in different cardiac cycles were statistically significant ( Z=-3.921--3.173, P<0.05). Conclusions:With the combination of radiomics and enhanced ECG 4DCT image, the microscopic changes of CT image features in the cardiac cycle can be amplifed. A new method for the assessment of left ventricular function changes was provided. The features such as median, mean may have more application potential.
RESUMEN
OBJECTIVE:To prepare Ibuprofen lysine sustained-release liquid suppository,and conduct the evaluation in vivo and in vitro. METHODS:Ibuprofen lysine sustained-release liquid suppository was prepared by using Poloxamer solution as main matrix,carbomer as bioadhesive agent,laurocapram as penetrant. The ratios of poloxamer 407(P407)-poloxamer 188(P188)and carbomer content were screened by using gel temperature,gel intensity,biological adhesion and release rate in vitro as indexes, and the concentration-time curves and pharmacokinetic parameters of prepared liquid suppository and common solid suppository af-ter rectal administration in Beagle dogs in vivo were compared. RESULTS:When the P407-P188 ratio was 1:1.2,the gel tempera-ture of sustained-release liquid suppository was 30.4-38.1 ℃,which was the nearest to the rectal temperature;when the content of carbomer was 0.8%,the in vitro release of sustained-release liquid suppository was in zero-order model,with favorable correlation (R2=0.996). The tmax of common solid suppository was 3.206 h,then plasma concentration decreased significantly,release time did not exceed 12 h,AUC0-∞ was 501.826 mg·h/L;tmax of sustained-release liquid suppository was 8.814 h,then plasma concentration decreased,release time exceeded 24 h,AUC0-∞ was 715.489 mg·h/L. CONCLUSIONS:Ibuprofen lysine sustained-release liquid suppository is successfully prepared,which shows better sustained-release effect and excellent correlation in vivo and in vitro than common solid suppository.