Objective To compare the dosimetry of three different radiation therapy plans [threedimensional conformal radiation therapy (3DCRT),intensity modulated radiation therapy (IMRT),intensity modulated arc radiotherapy (IMAT)].Methods Selected 15 cases with middle thoracic esophageal cancer,Varian Eclipse 8.6 planning systems were designed with 3DCRT,IMRT,IMAT,3DCRT using 5-8 coplanar radiation fields,IMRT using 7 coplanar radiation fields,IMAT using 2 radians.Three planned dose difference were compared.Results Compared with 3DCRT,IMRT and IMAT were better with heterogeneity index (HI),conformality index (CI),VPTV 95 ％,V5,V20,V35 of total lung,and V30 of heart (t =2.531,P＜ 0.05).There was no statistically significant difference for the V10,V15,V25,V30 mean dose of total lung,the mean dose of heart,the maximum dose of spinal cord,and the minimum dose of PTV among the three plans (t =1.325,P ＞0.05).Conclusion IMAT and IMRT are similar in the middle thoracic esophageal cancer radiotherapy target volume dose coverage and organs at risk protection,they are better than 3DCRT.IMAT in the monitor units and delivery time are less than IMRT.

Objective Using Eclipse and Pinnacle3 V 7.4f treatment planning sytems (TPS) for dose calculation of the CT images of simulation phantom,patients and homogeneous organization phantom,to compare the differences between the two TPS for the calculation of non-uniform organizations.Methods For the CT images of simulation phantom,patients and homogeneous organization phantom,the calculating results between the two TPS were compared,including the common used clinical indexes of V20 and V30 of the lung,D95 of the planning target volume,the doses of the ISO and eight points of interest inside ISO slice.Resuits For simulation phantom and patients,although the calculating differences of the isocenter doses between the two TPS were small,the differences of other indicators were large.For example,when using secondary collimator irradiation,the maximal D95 difference of planning target volume reached 10.17%for patients and 4.64%for simulation phantom.When using muhileaf collimator irradiation,the maximal D95 difference reached 10.74%for patients and 5.66%for simulation phantom.Sometimes the dose differences of points 1-4 at the edge of planning target volume were more than 10%.In addition,the V30 differences of the lung were large too.But for the homogeneous organization phantom,the calculating differences were small.Conclusions The calculating differences between the two TPS are less for simulation phantom than for patients,and more for simulation phantom and patients than for homogeneous organization phantom.

Objective To evaluate the validity of narrow-band imaging (NBI) system in detection of colorectal adenoma, as compared to that of endoscopy of the colon and rectum, in a systematic review. Methods Relevant literatures were retrieved from Medline (January 1966 to October 2008), OVID (January 1996 to October 2008), EMBASE (January 1980 to October 2008), Coehrane Library (Issue 3, 2008) and Chinese Biological Medicine Disk (CBM disk, January 1997 to October 2008). Quality of the literatures retrieved was assessed based on the Cochrane Reviewers' Handbook and Jadad's score. RevMan version 4. 2 software was used for meta-analysis. Results Seven randomized clinical trials (2838 patients) were included in the study. Compared with white-light colonoscopy, no significant difference was observed in terms of adenoma detection rate (OR 1.18, 95% CI 1.00-1.39, P=0.06) by NBI system, which could significantly improve total number of detection for fiat lesions of the colon and rectum (pooled WMD 0.14, 95% CI 0.02-0.26, P=0.02), but with a longer withdrawn time (pooled WMD 1.05, 95% CI 0.08-1.22, P<0.01). Conclusions Detection rate for flat lesions of the colon and rectum, not for adenoma, can be improved by NBI system and meanwhile its withdrawn time is prolonged, indicating that routine use of NBI system for detecting colorectal adenomas may be recommended only with its further refined technique.

ObjectiveTo study the efficacy of using multileaf collimators with different position and different degree in the treatment of nasopharyngeal carcinoma (NPC) using intensity-modulated radiotherapy techniques.Methods Ten patients withNPC were administered andanalyzed.Thepenumbra characteristics, dose of target, and radiation conformal indexes (CI) of mode T1 and mode T2 were measured and compared using dose volume histogram generated by Varian Eclipse three-dimensional planning computer system. Mode T1 :The angles of seven coplanar beams were 0°, 52°, 106°, 160°, 212°, 258°and 308°,respectively. There were no restriction on the position and degree of multileaf collimators. Parameters were set and optimized. Mode T2 :The beam angles and the parameters were as same as mode T1. According to the actual situations, the position and the degree of the multileaf collimators were changed. Then thedose optimization was performed. Results Target dose coverage in both mode T1 and T2 could be clinically accepted, and the CI were 0. 82 and 0. 83(t = -0. 25, P =0. 815). The maximum dose reductions in the lens, eyes, optic nerves and corneas were 28. 7% (t = 4. 80, P = 0. 000), 2. 7% (t = 2. 99, P = 0. 021),1.4%(t= 1.05,P=0.032), and 30.5% (t=2.99,P=0. 020), respectively. However, the mean dose and V35 of the parotid were increased by 0. 6% (t = - 2. 82, P = 0. 043) and 9.9% (t = - 2. 05, P =0. 038). ConclusionsOpimization of multileaf collimators can reduce the scattering and leaking rays. Compared with mode T1 ,controlling the position and degree of multileaf collimators could reduce the radiation dose to the eyes and optic-nerves, especially to the lens.

0.05).The variced recurrence rate in 1- and 2-year were 12% (3/25) and 20% (5/25) in TH glue group,and 39.1% (9/23) and 86.9%(20/23) in control group (P

Objective To research the feasibility of using three-dimensional CT (3DCT) associated with active breathing control (ABC) in determination of the individual internal tumor volume (ITV) for hepatocellular carcinoma (HCC) comparing the four-dimensional CT (4DCT).Methods After 4DCT scans of 15 HCC patients who had accepted TACE,completed the 3DCT scans associated with ABC in three ways of breathing:free breathing ( FB),end inspiration hold ( EIH),end expiration hold (EEH).4DCT images were sorted into 10 phases and the maximum intensity projection (MIP) images were constructed.The GTVs were manually contoured on 4DCT and 3DCT images (labeled as GTV0,GTV10.….GTV90,GTVMIP,,GTVFB,GTVEIH and GTVEEH).GTV0…GTV90,GTV0 and GTV50,GTV0,GTV20 and GTV50,GTVEIH and GTVEEH were respectively merged into IGTV1,IGTV2,IGTV3,IGTV4.The volume and geometry displacement of GTVs and IGTVs were compared.Results All patients were compatible with the ABC technique and completed the CT scans in two ways.The motion of diaphragm measured between 4DCT and 3DCT images was not significantly different ( 1.39 cm and 1.39 cm,t =-0.02,P =0.983 ),it was similar to the volume difference among GTV0,GTV20,GTV50,GTVEIH,GTVEEH and GTVFB (56.4,54.6,55.5,55.6,55.2,59.7 cm3,F =0.01,P =1.000 ).The comparison result of volume difference among IGTV1,IGTV2,IGTV3,IGTV4 and GTVMIP (77.9,71.4,73.4,72.3 and 66.3 cm3,F =0.02,P =1.000)were similar to the differences of geometry displacement in x,y and z axial among them (F =0.48,0.04,0.02,P =0.750,0.997,0.999,respectively).Conclusion The application of 3DCT associated with ABC in determination of the individual IGTV for HCC is feasible and safe comparing to 4DCT.

Objective To evaluate the accumulated doses to normal tissues and organs at risks (OARs) of patients with lung cancer in radiotherapy plans by using the deformable registration method,and make comparison with the empirical calculation method.Methods Ten patients with lung cancer were analyzed retrospectively.3D-CRT or IMRT plans were designed before treatment. CT to simulator was rescanned and the same treatment plan was redesigned during radiotherapy. Based on the deformable registration method,the Mimvista software was used to calculate the accumulated doses to normal tissues and OARs in two CT images respectively.The empirical estimation algorithm was calculated by the linear relationship between the fractions and the total prescribed dose.Results The target coverage of patients had no significant difference in two plans.There were no significant differences in all the dose volume parameters for normal tissues and OARs,except the mean dose to right lung( t =2.98,P ＜ 0.05 ) when the the same plan was conducted in position-setting and reposition CT images.Conclusions The empirical estimation for the accumulated dose could be used to evaluate the dose and volume parameters for normal tissues and OARs in lung cancer by the same plan.

Objective To compare the dosimetric differences of three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT) and volumetric modulated arc radiotherapy(V-MAT) for external beam partial breast irradiation.Methods Twelve patients with breast cancer receiving breast-conserving surgery and external beam partial breast irradiation were enrolled.Three different techniques including 3D-CRT,IMRT and V-MAT were designed for each patient.The dosimetry in the target,the dose to the organs at risk(OAR),the MU and delivery time were compared.Results All three plans met the clinical requirement. 3D-CRT showed the worst conformity in target. V-MAT provided the lowest target coverage and homogeneity in target.3D-CRT plans showed the lowest values for the V5,V10,mean dose and the highest values for V30 in the ipsilateral lung.No statistically significant differences were observed in V20 of the ipsilateral lung among three plans.V-MAT showed the lowest values in ipsilateral normal breast volume 15,20 and 25 Gy post-irradiation.For V5,the mean and max dose in heart,the mean dose in contralateral lung and the mean,max dose in thyroid,IMRT and 3D-CRT showed the highest and lowest value respectively(z =-2.94 - -2.09,P ＜ 0.05 ).The MUs in 3D-CRT,IMRT and V-MAT were 417.6 ± 34.4,772.8 ± 54.4 and 631.0 ± 109.0,respectively (z =- 2.93, - 2.76,-2.93,P ＜ 0.05 ). V-MAT significantly reduced the delivery time. Conclusions V-MAT shows significant advantages in reducing the dose in the ipsilateral normal breast and the delivery time compared with 3D-CRT and IMRT.

ObjectiveTo investigate the dosimetric difference in the application of RapidArc using 6 and 15 MV X-rays for radiotherapy of multiple hepatic malignancy.MethodsA total of 12 cases with multiple hepatic tumors ( primary 5 cases and secondary 7 cases) were selected.All patients underwent the three dimensional CT simulation in free breathing.For each patient,RapidArc plans with single or two 358° arcs using 6 or 15 MV X-rays were designed respectively,the prescription dose was 2Gy per fraction × 25 fractions.The dosimetric differences were compared among RapidArc plans.ResultsAll of RapidArc plans could meet the clinicalrequirement.There were no significant differences in the conformity index ( CI ),homogeneity index ( HI),the maximum dose and the minimum dose of PTV among RapidArc plans ( P ＞ 0.05).All the CI could get to 0.91 and HI could get to 0.88.In the RapidArc plans with two 358° arcs,the Vs,V10,V15 of normal liver were higher than with single arc,while V20,V25,V30,V35,V40 were lower than with single arc.There were no significant differences in the different radiation dose of normal liver,stomach,duodenum and spinal cord among different plans ( P ＞0.05 ).The monitor units of RapidArc plans using 6 MV X-rays increased 12％ compared to 15 MV averagely.CondusionThe 6 MV X-ray would be selected chiefly in the radiotherapy of multiple haptic tumor using RapidArc with whole arc(s).

Objective To study the value of using endoscopy iodine staining combined detecting the expression of p53, survivin and telomerase in the diagnosis of early esophageal carcinoma and precancerous lesions. Methods Three hundred patients who received routine gastrescopy and had high risk of esophageal carcinoma were examined by the iodine dyeing on their esophageal mucosa with 2. 5% Lugol solu-tion. Multiple biopsies were taken from the unstained or light-stained areas when their diameters were over 5mm for pathology diagnosis. The expression of p53, survivin and telomerase were detected by immunohistochemical staining. Results With the Lugol staining method, the incidences of light, moderate and high grade dysplasia and early esophageal carcinoma were 16. 3% ,9. 7% ,3.7% and 4. 3% respectively. The expression of p53, survivin and telomerase were related and the unstained were related to the expression of p53, survivin and telomerase in dysplasia and early esophageal carcinoma. Using endoscopy iodine staining combined testing p53, survivin and telomerase showed sensitiv-ity of 100%, specificity of 92. 3% and accuracy of 91.8% to diagnose of early esophageal carcinoma and high grade dysplasia. Conclusion Lugol solution chromoendscopy combined assay of p53, survivin and telomersse might be useful in the diagnosing early esophageal carcino-ma and precancerous lesion.