Background and purpose:The curative effect with radiotherapy or chemotherapy alone for the patients with unresectable stage Ⅲ non-small-cell lung cancer was poor. The 5-year survival was only 5-10 percent. Concurrent chemoradiotherapy could achieve better local control and overall survival of those patients and it had been reported that the 5-year survival was improved to 15.8 percent, but the toxicity were much more severe at the same time. We prospectively evaluated the efficacy and toxicity of concurrent chemoradiotherapy with low dose weekly paclitaxel for unresectable stage Ⅲ non-small-cell lung cancer and tried to make the regime more tolerable without the deterioration of treatment response. Methods:Forty-eight patients with unresectable stage Ⅲ non-small-cell lung cancer were randomized into low dose weekly paclitaxel group and control group.Both groups were treated by the standard fractionation schedule. All patients were irradiated 2.0 Gy/per fraction,five fractions a week,the total radiation dose was 60-64 Gy for tumor. Patients in the low dose weekly paclitaxel group received chemotherapy with 45 mg/m 2 of paclitaxel on every Monday; the patients in control group received 50 mg/m2 of cisplatin on days 2-4 and day 23-25, and 135 mg/m 2 of paclitaxel on days 1 and 22 concomitant with the radiotherapy.Results:The CR (complete response) rates of low dose weekly paclitaxel and control group were 21% and 13% respectively(P0.05).Conclusions:The patients treated by low-dose weekly paclitaxel group showed that both survival fraction and the period of local tumor control were higher than in control group. Additionally, low dose weekly paclitaxel concomitant with radiotherapy was well tolerated and were not statistically different from control group in terms of toxicities.

Objective To explore the association between the genetic polymorphism of hypoxia inducible factor 1 α (HIF-1α) G1790A and the radiosensitivity of nasopharyngeal carcinoma.Methods A total of 189 patients with nasopharyngeal carcinoma treated with radical radiotherapy were followed-up for 3 years.The patients were divided into cured group with 135 cases and recurrence group with 54 cases by clinical follow-up results.PCR-RFLP was used to determine the mononucleotide genotypes of HIF-1α G1790A.Results The observed genotype frequencies of HIF-1α gene 1790 (G→A) for GG, GA and AA were 70.04% , 20.74% , 2.22% in cured group and 59.26% , 38.89% , 1.85% in recurrence group, respectively.The allele frequencies for G and A were 87.4% , 13.9% in cured groups and 78.7% ,21.3% in recurrence group, respectively, without significant difference in distribution of allele frequencies between the two groups(x2 =6.919, P =0.077).Conclusions The genetic polymorphisms of HIF-1α G1790A might be related with the radiosensitivity of nasopharyngeal carcinoma.

Objective To commission a Mobetron intra-operative mobile accelerator and analyze the characteristics of its electron beams. Methods The dosimetrie characteristics of the electron beams genera-ted by Mobetron accelerator were measured and compared with those generated by conventional accelerator (Primus, Siemens). M oberton accelerator can generate electron beams of nominal energies of 4,6,9 and 12 MeV. The measurement items were as followings : percentage depth dose perpendicular to water phantom sur-face and beam profiles parallel to water phantom surface, output factors, applicator leakage, electron beam at-tenuation made by lead blocks,and machine output calibration. The measurement devices included a three-dimensional ( 3 D) water scanning phantom, an electrometer, a 0.6 cm3 Farmer ionization chamber, a parallel-plate ionization chamber and solid water slabs. During measurement, all applicators of different tilt angles and diameters were attached to the machine head,and their ends were adjusted to be tangent to the phantom surface. Results Except for the 12 MeV,skin dose for all energies was no more than 90%. The skin dose was higher for Mobetron accelerator electron beams than for regular electron beams. The Dmax depth in water for a 10 cm flat applicator were 0.7,1.3,2.0 and 2.2 cm for the 4 energies,respectively. The depths of 90% dose were 1.0,1.8,2.7 and 3.6 cm, respectively. The selected flat applicator was just 1 cm larger than the tumor bed. But for the beveled applicators,the field flatness and symmetry became worse,and con-sequently,the applicator size had to be selected based on the isodose distribution. The leakage dose at 1 cm outside the applicator was 1.2% ,5.1%, 10.0% and 9.1%, respectively. The lead thickness for full block was 1.5,3.0,4.5 and 6.0 mm,respectively. Conclusions Through the commissioning of Mobetron accel-erator, the machine characteristics are understood, and the data for clinical implementation and routine quality assurance are acquired.

Objective This study analyzes the effect of the shrinkage of thermoplastic mask on patient positioning. Methods Design of the two test. Test 1:thermoplastic film shrinkage test. Get some thermoplastic film by the size of 10 cm×5 cm, extrude it at a certain rate after heated. Measure the length of thermoplastic film on different time, and calculate the contraction. Test 2:phantom test. Take advantage of head and neck phantom, and simulate the procedure that from making mask for patients to radiation therapy. Measure the off set of isocenter which caused by the contraction of thermoplastic mask. Results The largest shrinkage of thermoplastic had happened in 20 minutes. Different tensile ratio had little effect on the shrinkage. The offset of isocenter which caused by the shrinkage of thermoplastic mask were:LR ( -0?? 1± 0?? 3) mm,SI (-0?? 2±0?? 2) mm, AP (0.6±0?? 4) mm,respectively. There was little change in the course of six weeks ( P= 0.185?0?? 961). Conclusions The cooling time should be more than 20 minutes, when making a mask for the patient. The setup errors which caused by the shrinkage of thermoplastic mask is at an acceptable level on this premise.

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 The aim of this study is to evaluate the feasibility of using orthogonal kilo voltage fluoroscopic imaging(OKVFI)for setup correction in image guided radiotherapy of the liver.Methods After positioned the patients with liver cancer implanted with silver rings on the accelerator equipped with kilo voltage X-ray volume imaging(XVI),averaged OKVFI and cone beam CT(CBCT) volumetric images were acquired.A total of 90 datasets of averaged OKVFI and 90 datasets of volumetric images for 10 patients were obtained.The couch shifts obtained by the matching between OKVFI and digitally reconstructed radiograph were compared tu those achieved by the registration between CBCT and 4D reference average CT.On the comparison of the two different matching metheds.the Pearson coefficient was used to analyzed the correlation and Bland-Altman analysis to discern the consistence.Results The Pearson coefficient of correlation for the patient position shifts were R2=0.821.0.771 and 0.909 in the left-right (LR),anterior-posterior(AP)and superior-inferior(SI)directions respectively.95% CI were-2.30 -1.53(LR),-2.06-3.01(AP)and-2.69-1.53(SI)respectively.Within a±3 mm tolerance were 97.78%.95.56%and 96.67%respectively.Conclusions OKVFI has hish correlation and consistence with CBCT image on the setup correction.It is feasible to implement position correction with OKVFI in clinic practice.

Objective To investigate the impact of anatomical landmarks on registration in image?guided radiotherapy (IGRT) for central and peripheral lung cancer. Methods Twenty?five patients with central or peripheral lung cancer for IGRT were enrolled in this study. Kilo?voltage cone?beam CT ( kV?CBCT) scanning was acquired before irradiotion. Tumor coverage on CBCT was assessed using gross tumor volume (GTV), clinical target volume (CTV), and planning target volume (PTV) contours according to tumor alignment, carina registration, and spine registration, respectively. The grading analysiswas based on visual tumor assessment as follows:grade 0, tumor within GTV;grade 1, tumor outside GTV but inside CTV;grade 2, tumor outside CTV but inside PTV;and grade 3, tumor outside PTV. Results Totally 177 sets of kV?CBCT of 25 patients was collected. According to the registration landmarks of the tumor, carina and spine for central lung cancer, the percentages were 57?55%, 53?77% and 16?04% in grade 0, 39?62%, 45?28%and 58?49% in grade 1, and 1?89%, 0?94% and 25?47% in grade 2, respectively. For peripheral lung cancer, the percentages were 47?89%, 14?08% and 2?82% in grade 0, 43?66%, 29?58% and 45?07% in grade 1, and 8?45%, 40?85% and 35?21% in grade 2, respectively. Conclusions For central lung cancer,the tumor was recommended as the best registration landmark, and the carina was recommended as well, while the spine was not recommended. For peripheral lung cancer, the tumor was recommended as the best registration landmark, while the spine and the carina were not recommended.

Objective To design and develop a treatment unit selecting system in aim of enhancing work efficiency and safety,adjusting treatment unit workload,improving quality of medical care.Methods Various treatment techniques,immobilization devices and setup verification devices were modeled in software.Workload of treatment units were extract from the Record and Verify System.These two types of information were then combined with the unit's workload capability to calculate the optimal radiotherapy apparatus for tumor patient.Results The system had finished selecting radiotherapy apparatusv for more than 5 000 patients since its taking place of the old patient selecting methods.Maximum variation of daily treatment duration between treatment units had decreased from 4-5 hours (mean 4.22 hours) to 1-2 hours (mean 1.84 hours) since the system have been put into operation.Workload and device configuration of various units could be controlled by easily editing of the system configuration file.Conclusions The system developed not only accomplish patient selecting in an optimal and safe way,but also provide a way of easily control the treatment unit workload.

Objective To investigate the inhibitory effect of reiniosidc C (RC) on asymmetric dimethylarginine (ADMA)-induced soluble interacellular adhesion molecule-1 (slCAM-1) expression and its mechanisms. Methods Human umbical vein endothelial cells (HUVEC 12) were cultured.The level of slCAM-1 in the conditioned medium was determined by ELISA. Changes in intracellular reactive oxygen species (ROS) levels were determined by measuring the oxidative conversion of cell permeable 2', 7'-dichlorofluorescein diacetate (DCFH-DA) to fluorescent dichlorofluorescein (DCF) in fluorospectro- photometer, and the nuclear factor-κB (NF-κB) DNA-binding activity was determined by electrophoretic mobility shift assays (EMSA). Results sICAM 1 expressions [(138.02±16.40), (194.52±11.14), (274.28±13.11)ng/L]and the generation of ROS[(75.64±5.22),(100.18±11.15),(107.23±13.45)units] in HUVEC-12 were time dependently increased by ADMA (30 μmol/L). Furthermore, thc generation of ROS [(85.33±8.68), (70.69±7.65),(59.12±4.15)units], activation of NF-κB activity and expression of sICAM-1 [(336.58±23.32),(203.27±25.18) ,(174.13±14.53)ng/L] induced by ADMA were inhibited by reinioside C (1,3,10μmol/L) in a dose-dependent manner. This effect was found to be the same by L-arginine (0.5 mmol/L) as NOS substrate and by pyrrolidine dithiocarbamate (PDTC) (10 μmol/L)as inhibitor of NF-κB.Conclusions Reinioside C attenuates the increase of sICAM-1 induced by exogenous ADMA

Objective To investigate the correlation between setup error and couch position error in radiotherapy.Methods A total of 25 patients with thoracic and abdominal tumors who recently finished image-guided radiotherapy were randomly selected.The data on couch position during treatment were obtained through the record validation system, and then the couch position error was calculated.The Pearson correlation analysis was used to investigate the correlation between setup error and couch position error during treatment.Results In the ≥5 setup errors among the 25 patients, the correlation coefficient between random setup error and random couch position error was 0.83(P=0.00), and the correlation coefficient between systematic setup error and systematic couch position error was 0.36(P=0.11).Conclusions In radiotherapy, the random setup error is highly correlated with the random couch position error, while a moderate or low correlation exists between the systematic setup error and the systematic couch position error.