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 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.

Objective To compare the difference of decreasing radiation-induce lung injure among CT scans including active breathing control (ABC), slow CT scan and general axial CT scan under free breathing (FB) in precise radiotherapy of peripheral non-small cell lung cancer (NSCLC). Methods Ten patients of peripheral NSCLC were included. For each patient, three CT scans were obtained: (1) the general axial CT scans under FB;(2) the fast spiral CT scans under ABC;(3) the slow CT scans under FB. Three treatment plans based on three CT scans were optimized. Gross tumor volume (GTV), clinical target volume (CTV) and planning target volume (PTV) along with V20 (lung volume accepted > 20 Gy/all lung volume ×100%) and Dmean (average dosage accepted irradiation of all lung)of three treatment plans were calculated and compared. Results The GTV and CTV of the slow CT plan seem in largest, and those of ABC plan in smallest, but no statistics signification among the three plans (F = 1.513, P = 0.238;F = 1.376, P = 0.270). However, The PIV of the FB plan was largest, and the difference of PTV between plans of ABC and FB, plans of slow CT scans and FB were statistics significant (F = 26. 148, P = 0.000). The differences of V20 and Dmean between plans of FBand ABC, plans of FB and slow CT scans were statistics significant yet (F = 7.623, P = 0.002;F = 18.217, P = 0.000). Conclusion Compared with FB conditions, ABC or the slow CT scan method in precise radiotherapy of peripheral NSCLC can decrease radiation volume and dose to normal tissues as well as the probability of decreasing radiation-induce lung injure.

Objective To compare the dosimetric differences of target volume and organ at risk between intensity-modulated arc therapy (IMAT) and simultaneously integrated boost intensity-modulated radiotherapy (SIB-IMRT) in nasopharyngeal carcinoma. Methods IMAT and SIB-IMRT treatment plans of 10 nasopharyngeal carcinoma cases were generated by Varian Eclipse ver8. 6 treatment planning system. The dosimetric parameters of target volume and organ at risk (OAR), the monitor units (MU) and treatment time were compared between IMAT and SIB-IMRT treatment plan. Results The conformal index ( CI ) of PTV, PTV1, PTV2 of IMAT and SIB-IMRT were 0. 71 and 0. 75 ( Z = - 2. 32, P ＜ 0. 05 ), 0. 54 and 0. 59 (Z= -2.56,P＜0.05), 0.71 and 0.78(Z= -2.52,P＜0.05), respectively. the homogenous index (HI) of PTV, PTV1, PTV2 of IMAT and SIB-IMRT were 10.5 and 11.2(Z= -0. 84,P＞0.05),13. 1 and 17. 1(Z= -1.68,P＞0.05) and 14. 1 and 13.3(Z= -1. 01,P＞0.05) respectively;the brain-stem mean does were 3512. 8 cGy ± 406. 2 cGy and 3384. 3 cGy ± 361.3 cGy ( Z= - 1.82, P ＞ 0. 05 ); the brain-stem maximum dose were 5528. 1cGy ± 192. 9 cGy and 5727. 5 cGy ± 356. 3 cGy ( Z = - 1.12, P ＞ 0. 05 ); the maximum dose of spinal-cord were were 4186. 1cGy ± 88.7 cGy and 4390. 2 cGy ± 74. 9 cGy ( Z =-2. 38 ,P ＜ 0. 05 ). There were no significant differences between parotid dose and normal tissue ( P ＞0. 05. ) MU were 606 ± 96 and 1308 ± 213 for IMAT and SIB-IMRT ( Z= - 2. 52, P ＜ 0. 05 ). Conclusions The IMAT plan showed a better conformal index than SIB-IMRT plan, with the same dosimetric parameters of the target volume and OAR. The IMAT plan could reduce normal tissues dose, monitor units and treatment time in the treatment of nasopharyngeal carcinoma.

Objective To compare and analyze the characteristics of intensity-modulated arc therapy (IMAT) versus fixed-gantry intensity-modulated radiotherapy (IMRT) in the treatment of cervical esophageal cancer.Methods Ten patients treated in our radiotherapy center were selected for this study.Based on the identical CT and planning target volume (PTV), two IMAT plans were generated with Eclipse ver8.6 planning system.IMAT1 consisting of a single 359.8° rotation, and IMAT2 consisting of two coplanar 359.8° rotations.PTV were prescribed to 60 Gy in 30 fractions.Planning objectives for PTV,corresponding with the IMRT plans, were V98 larger than 97% and V110 no more than 15%.The maximum dose of spinal-cord was constrained below 45 Gy.One-way ANOVA were applied to dose-volume values for PTV and OAR from DVH.Results There were no significant differences between IMRT and IMAT in PTV D98, V98, CI or total-lung V5, V10, V30, V40, V50 and mean lung dose (all P > 0.05).However, the differences were significant in terms of D2, V110 and HI of PTV, V20 of the total-lung (all P<0.05).On the MU,IMRT = 1174.8 MU,IMAT1 =709.7 MU,and IMAT2 =803.8 MU (F =39.25,P =0.000).On the treatment time,IMRT= 14.9 min,IMAT1 = 1.9 min, and IMAT2 =2.66 min (F=45.14,P=0.000).Conclusions IMAT is equal to IMRT in dosimetric evaluation.Due to much less MU and delivery time,IMAT is an ideal technique in treating patients by reducing the uncomfortable influences which could effect the treatment.However, IMAT1 is slightly inferior to IMAT2.

Objective To optimize the registration template of kilovohage cone-beam CT (CBCT) guided radiotherapy in whole breast irradiation(WBI)after lumpectomy of breast cancer.Methods From April 2006 to July 2009,twelve patients undergoing WBI with intensity-modulated radiotherapy (IMRT)were recruited in this study.All patients were performed with both conventional planning CT and CBCT integrated on Varian 23 EX.Six distinguishable referenee points(the diameter 1 mm)around the lumpectomy cavity and the surrounding gland on the planning CT image were marked.The images were manually registered offline based on the breast surface,surgical clips,breast gland,contiguous rib,ipsilaterai lung and its external contours,respectively.The same six reference points were then marked on the CBCT image.The performance of the five registration templates was compared using the concept of registration error,while the registration time was taken into account.The registration error was calculated based on the six reference points'translations between the planning CT image and CBCT image,and analyzed with SPSS 13.0 software using one-way ANOVA.Results The values of the registration error for the breast surface,surgical clips,breast gland, contiguous rib,ipsilateral lung and its external contours were(0.60±0.20),(0.43±0.15),(0.49±0.19),(0.69±0.36)and(0.94±0.49)cm,respectively,and the registration time were(3.8±1.1),(3.0±0.9),(4.7±1.7),(4.3±1.3)and(4.5±1.3)min,respectively.There was no statistical difforence between the breast surface,surgical clips and breast gland registration template(t=0.48-1.36,P>0.05),the same result trend to contiguous rib compared with ipsilateral lung(t=2.00,P=0.055),however,there was significant difference between surgical clips and the last two registration methods(t=2.08-4.08,P<0.05).Conclusion In this initial study with a modest number of patients,surgical clips show a best registration template from the standpoint of accuracy and efficiency,whereas contiguous rib and ipsilateral lung are not an ideal method.