At present,intensity modulated radiation therapy has been the main treatment of nasopharyngeal carcinoma.In the course of 6-7 weeks,most physicians use the initial formulation of the radiotherapy plan.Studies have indicated that the reduction of primary tumor and lymph nodes,as well as the reduction of normal tissue and body surface profile due to the weight loss,will affect the dose distribution of the target and the organs at risk,so as to influence the therapeutic effect of some patients.Therefore,it is necessary to reset and modify the target volumes during the radiotherapy for nasopharyngeal carcinoma.

Intensity modulated radiation therapy(IMRT)has become the mainstay of treatment modal-ity for nasopharyngeal carcinoma(NPC). The whole treatment course generally continues 7 to 8 weeks. With the radiotherapy proceeding,the patients exhibit oropharyngeal reaction aggravating,weight losing and tumor shrinking,resulting in the changes of tumor target and surrounding tissue. Those changes may influence the dose distribution of tumor and organ at risk. It is necessary to modulate target volume during radiotherapy of NPC.

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 the displacements of the clips in the cavity measured with orthagonal kilovoltage (KV) X-my plain film in conditions of moderate deep inspiration breathing hold(mDIBH) and free breath (FB), and compare the margins from clinical target volume (CTV) to planning target volume (PTV) based on the displacements. Methods Before radiotherapy, 2 and 5 sets of orthogonal KV plain film were respectively collected in mDIBH and FB group, then the automatic registration of the reconstructed KV plain film and DRR derived from the planning OF images was finished. In conditions of mDIBH and FB, the displacements of the selected clip at the same location in the different directions and of the different selected clips in the same direction were compared. The margins in three dimensional directions were calculated and compared in conditions of mDIBH and FB . Results In FB hold group, the difference of displacement in left-right (LR), cranial-caudal (CC) and anterior-posterior (AP) directions were statistically significant between the clips at the cranial and caudal border of the cavity (9. 7 mm and 10. 6 nun (Z = -2. 12,P =0. 037) ,7. 3 mm and 8. 3 mm (Z = -2. 31 ,P=0. 041) ,15.5 mm and 16. 1 nun (Z = -2. 32,P = 0. 041)), but not statistically significant for the clips at the bottom and lateral P=0.814),15.7 mm and 16.5 mm (Z=-0.26,P=0.856)). The corresponding differences in the different directions were statistically significant (5.0 mm and 7. 8 mm(Z = -2. 31, P =0. 036), 5.0 mm and 9. 3 nun (Z= -2. 21,P=0. 021),7. 8 mm and9.3 mm (Z= -2. 11,P=0.041)). In FB group, the differences of the displacements of the four selected clips were statistically significant in CC and AP directions (7.3 mm and 8.4 mm (Z= -2.45,P=0.021), 15.5 mm and 16.5 mm (Z= -2.41,P= 0.043)), but not in LF direction (10.6 nun and 10.6 mm (Z= -0.24,P=0. 815)). In mDIBH group, the displacements in LF direction were statistically significant (4. 4 mm and 5.4 mm (Z = -2. 31, P = O. 031)), but not in CC and AP directions (8. 6 mm and 8.6 mm (Z =-0. 21, P = 0. 815), 10. 5 mm and 10. 8 mm (Z = -0. 27 ,P =0. 754)). There were statistically significant difference of the margins in LF and AP directions (9.7 mm and 5.0 mm (Z= -2.34,P=0.029),15.5 mm and 9.3 mm (Z= -2. 31,P= 0.021)), but not in CC direction (7.3 mm and 7. 8 mm (Z= -0.29,P =0.770)) between mDIBH and FB conditions. Conclusions The margins extended from CTV to PTV for EBPBI should be determined based on the respiratory status, border location and border direction.

Objective To compare the position,volume and matching index (MI) of patientspecific internal gross tumor volume (IGTV)delineated by 4 different approaches based on three- dimensional and four - dimensional CT ( 3 DCT and 4 DCT ) image for primary esophageal cancers.Methods Thirteen patients with primary esophageal cancer underwent 3DCT and 4DCT simulation scans during free breathing,and the patient were divided into group A (tumor located in the proximal thoracic esophagus) and B (tumor located in the mid-and distal thoracic esophagus).IGTV were delineated using four approaches: The gross tumor volume (GTV) contours from 10 respiratory phases were combined into IGTV10 ;IGTV2 was acquired by combining the GTV from 0％ and 50％ phases; IGTVMIP was the GTV contour delineated from the maximum intensity projection (MIP) ;IGTV3D was acquired from the enlargement of 3 DCT-based GTV by each spatial direction on the motion amplitude measured in the 4DCT.ResultsTarget movement in lateral (LR),anterio-posterior (AP),superio-inferior (SI) directions showed no statistically significant difference (0.11 cm,0.09 cm,0.18 cm,respectively; χ2 =1.06,P=0.589),and there was no statistically significant difference in centroid positions between IGTV10 and IGTV2 or IGTV3D in group A (t =-2.24,-0.00,P =0.089,- 1.000 ),MI between IGTV10 and IGTV2,IGTV10 and IGTV3D were 0.88,0.54,respectively. For group B, target movement amplitude in SI direction was bigger than in LR, AP ( 0.47 cm,0. 15cm,0. 12 cm,X2= 12.00,P = 0.002).Therewasno significantdifference betweenIGTV10 andIGTV3D inLR, AP, SI ( t =- 0.80.- 0.82,- 1.16,P = 0.450.0.438.0.285 ), MI was 0.59 ; but the target center coordinates was demonstrated significant difference in SI between IGTV10 and ICTV2 for group B ( t = 2.97.P = 0.021 ), Mlwas 0.86.Thevolume of IGTVMIPwassmaller thanIGTV10 ( t =- 2.84,P = 0.025 ), but the position of IGTv10 and ICTVMIp were with no statistically significant difference in the LR,AP,SI ( t =- 0.25,0. 84. - 1.22,P = 0. 809,0.429.0.263 ) ,MIbetweenIGTV10andIGTVMIp was 0.78.Conclusions Patient-specific IGTV can be acquired from 4DCT with correct target coverage while avoiding a geographic miss for the thoracic esophageal cancer,but IGTV2 and IGTVMIP can not contain all the information about primary tumor position,shape.and size at different phases of the respiratory cycle.

Objective To investigate the correlation of position movement of primary tumor with interested organs and skin markers,and to investigate the correlation of volume variation of primary tumors and lungs during different respiration phases for patients with lung cancer at free breath condition scanned by four-dimensional CT (4DCT) simulation.Methods 16 patients with lung cancer were scanned at free breath condition by simulation 4DCT which connected to a respiration-monitoring system.A coordinate system was created based on image of T5 phase,gross tumor volume (GTV) and normal tissue structures of 10 phases were contoured.The three dimensional position variation of them were measured and their correlation were analyzed,and the same for the volume variation of GTV and lungs of 10 respiratory phases.Results Movement range of lung cancer in different lobe differed extinct:0.8 - 5.0 mm in upper lobe,5.7 -5.9 mm in middle lobe and 10.2 - 13.7 mm in lower lobe,respectively.Movement range of lung cancer in three dimensional direction was different:z-axis 4.3 mm ± 4.3 mm＞ y-axis 2.2 mm ± 1.0 mm ＞ x-axis 1.7 mm ± 1.5 mm ( x2 =16.22,P =0.000),respectively.There was no statistical significant correlation for movement vector of GTV and interested structures (r =-0.50 - -0.01,P =0.058 - -0.961 ),nor for volume variation of tumor and lung ( r =0.23,P =0.520 ).Conclusions Based on 4DCT,statistically significant differences of GTV centroid movement are observed at different pulmonary lobes and in three dimensional directions.So individual 4DCT measurement is necessary for definition of internal target volume margin for lung cancer.

Objective This study was designed to compare the safety and efficacy of fast track surgery (FTS) with conventional perioperative management in colonl cancer patients undergoing radical resection.Methods From May 2011 to May 2013,66 patients with colorectal cancer were randomly assigned to FTS group and control group.Outcomes were assessed by length of postoperative hospital stay,medical cost,nutritional status,gut function,and postoperative complication.Results FTS group was associated with a significantly shorter postoperative hospital stay,lessmedical cost,earlier first passage of flatus,less loss of body weight in the postoperative period compared with control group,and there were no differences in morbidity or mortality between two groups.Conclusion The radical resection under the guidence of fast track rehabilitation is safe and effective method.Significantly reduce patients' perioparative stess response and accelerate the recovery.

ObjectiveTo investigate the effect of the displacement of the selected silver clip in the different respiratory state achieved by active breathing control ( ABC ) system on the displacement of the geometry constituted by all of the silver clips at the border of the cavity in external-beam partial breast irradiation (EB-PBI).MethodsTwo sets of CT images in state of moderate deep inspiratory breathing hold (mDIBH),deep expiratory breathing hold (DEBH),and free breath (FB) were acquired in the same CT simulation assisted by ABC system for each of the 27 patients after breast conservative surgery.All silver clips in the cavity were delineated based on each set of CT images.Thereafter,the irregular geometry based on the silver clips as the vertices was automatically formed.Four selected clips located at the top,bottom,lateral border and medial border of the cavity were correspondingly manually registered based on automatic registration of the CT images acquired in the same or different state of respiration including mDIBH,FB,and DEBH.The displacement of center of the geometry in the direction of right-left (RL),anterior-posterior (AP),and superior-inferior (SI) separately based on automatic registration and manual registration was evaluated.The difference of the displacement was analyzed by Kruskal-Wallis H-test and Kolmogorov-Smirnov Z-test.Results When registered between mDIBH and mDIBH,FB and FB,DEBH and DEBH,the differences of the displacement of the center of geometry were not statistically significant (H =0.00 - 1.76,P=0.184-0.954). When registered between mDIBH and DEBH,the differences were statistically significant ( Z =11.31 - 23.00,P =0.000 - 0.001 ).There were statistically significant differences in the displacement of geometry center based on the selected silver clip between different registration forms in AP and SI directions (Z=4.76-25.54,P=0.000-0.029).ConclusionsThe difference of intrafraction displacement of the geometry constituted by the clips between the same respiratory states in the three dimensional direction is not statistically significant,but the difference is statistically significant between the different respiratory states in AP and SI directions.

Objective To analyze artifacts of gross tumor volume (GTV) and correlated factors in each phase images of four dimensional CT (4DCT) for peripheral lung cancer based on three dimensional CT (3DCT) assisted with active breathing control.Methods Nineteen patients with peripheral lung cancer underwent 3DCT (CTFB) and 4DCT simulation scans during free breathing and then underwent 3DCT simulation scans in end inspiration hold (CTEIH) and end expiration hold (CTEEH) assisted with active breathing control.The relative deviations (Devref) between the reference GTV (GTVref) and the GTVsdelineated based on CTFB (GTVFB) and all phases of 4DCT were calculated respectively.Correlations between GTVref and Devmax and between the tumor motion in the cranio-caudal (CC) direction and Devref were analyzed.Results The maximum median Devref of GTV was GTVFB with 17.83％,and the maximum median Devref of the GTV in all phases of 4DCT was GTV30 with 17.20％.A significant negative correlation was found between GTVEIH and Devmax (r =-0.691,P =0.001).The Devref was crrnelated with the tumor motion amplitude in the CC direction (r =0.323-0.617,P =0.005-0.150).The partial regression coefficient of influence of GTVref size and motion amplitude in the CC direction to the tumor Devmax were -0.500 and 0.583,P =0.002 and 0.001,respectively.Conclusions The GTV artifacts in different phase of 4DCT for the peripheral lung cancer were different to each other,and the influence of target displacement to artifacts was larger than that of target volume,so artifacts could be reduced by controlling breathing to reduce target displacement.

Objective To study the value of CT on defining the gross tumor volume (GTV) in three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy(IMRT), by comparing the GTV contoured on preoperative CT with postoperative pathology guided GTV in patients with non-small cell lung cancer (NSCLC). Methods Thirty-three patients with histologically proved NSCLC had had CT scan of the thorax before sugery. We contoured the GTV for both primary tumor (GTV-T) and the regional metastatic lymph nodes (GTV-N) on preoperative CT scan. The GTV-T was defined on lung window while the GTV-N on mediastinal window. The metastatic lymph node was defined as≥ 10mm in diameter of short axis,while