Objective To investigate the positioning errors of head and neck during intensity-modulated radiation therapy of nasopharyngeal carcinoma.Methods Nineteen patients with middle-advanced nasopharyngeal carcinoma (T2-4N1-3M0), treated by intensity-modulated radiation therapy, underwent repeated CT during their 6-week treatment course.All the patients were immobilized by head-neck-shoulder thermoplastic mask.We evaluated their anatomic landmark coordinated in a total of 66 repeated CT data sets and respective x, y, z shifts relative to their position in the planning CT.ResultsThe positioning error of the neck was 2.44 mm±2.24 mm,2.05 mm±1.42 mm,1.83 mm±1.53 mm in x, y, z respectively.And that of the head was 1.05 mm±0.87 mm,1.23 mm±1.05 mm,1.17 mm±1.55 mm respectively.The positioning error between neck and head have respectively statistical difference (t=-6.58,-5.28,-3.42,P=0.000,0.000,0.001).The system error of the neck was 2.33,1.67 and 1.56 higher than that of the head, respectively in left-right, vertical and head-foot directions;and the random error of neck was 2.57,1.34 and 0.99 higher than that of head respectively.Conclusions In the process of the intensity-modulated radiation therapy of nasopharyngeal carcinoma, with the immobilization by head-neck-shoulder thermoplastic mask, the positioning error of neck is higher than that of head.

Objective To research the clinical significance of acetated Ringer solution and succinylated gelatin in the fluid resuscitation of sepsis patients.Method Fifty-nine sepsis patients were divided into two groups:lactic acid Ringer solution and hetastarch (group A,27 cases)and acetated Ringer solution and suecinylated gelatin (group B,32 cases),compared the fluid resuscitation and other parameter.Results There were no significant difference in the central venous pressure,mean arterial pressure and the dose of noradrenaline (P ＞ 0.05).The activated partial thrombeplastin time in group A was longer than that in group B[(58±10),(74±13)s vs(48±7),(54 ±11) s in 6,24 hours],fibrinogen concentration was lower than that in group B [(3.3 ±0.8),(1.6±0.3)g/L vs (4.2±1.1),(2.1±0.2)g/L in 6,24 hours] (P＜0.05).Serum lactic acid,creatinine,calcium concentration in group A [(6.9±0.8)retool/L,(289 ~ 27)μ mol/L,(2.1 ±0.3)mmol/L]were higher than those in group B [(3.2 ±1.1)mmol/L, (193 ±42)μmol/L, (1.7±0.2)mmol/L](P＜0.05),there was no difference in APACHE Ⅲ scores on the third day between two groups (P＞0.05).Conclusions Acetated Ringer solution and succinylated gelatin in the fluid resuscitation of sepsis patients has the same effect,but fewer impacts on serum coagulation,serum lactic acid and renal function than lactic acid Ringer solution and hetastareh.They may be more suitable for fluid resuscitation of sepsis patients,but hypecalcemia is easy to happen,and there is no significant evidences proving the prognosis.

Objective To investigate the effect of reformative ventilation method (head-high leg-low 30°-declivate prone position ) in the ventilation of acute respiratory distress syndrome ( ARDS ) patients, and compared with normal prone position ventilation. Methods Forty-four patients of ARDS underwent ventilation were divided into prone position group (22 cases) and reformative prone position group (22cases) by random digits talle. Continuous 30° semireclining position was kept in normal time. The patients of the two groups underwent different prone position ventilation 4 hours every day,and indexes of hemodynamics and respiration before,during and after prone position ventilation were recorded and analyzed. Results After prone position ventilation, oxygenation index of two groups improved similarly (P ＞ 0.05 ). In prone position group, lung compliance decreased [2 h, ( 25.6 ± 5.8 ) ml/cm H2O ( 1 cm H2O = 0.098 kPa) vs. ( 37.2 ± 20.5 )ml/cm H2O] ,average airway pressure increased [2 h, ( 18.5 ± 3.9) cm H2O vs. ( 15.6 ± 5.3 )cm H2O] ,heart rate increased [2 h, ( 112.0 ± 16.2 ) beats/min vs. ( 102.0 ± 11.3 ) beats/min], mean arterial blood pressure decreased [2 h, (86.0 ± 6.7) mm Hg ( 1 mm Hg = 0.133 kPa) vs. (93.5 ± 7.5 ) mm Hg] ,central venous pressure increased[2 h, ( 15.5 ± 3.3 ) cm H2O vs. ( 12.6 ± 4.3 ) cm H2O]. These changes persistently existed during prone position ventilation (P ＜ 0.05 ),and they disappeared in 1 hour when recovered to 30 °semireclining position. Conclusion Reformative prone position ventilation not only has same effect on improving oxygenation index, but also obviates adverse effect on lung compliance and hemodynamics.

Objective To evaluate the effects and side effects of three different recruitment maneuvers (RM) in acute respiratory distress syndrome (ARDS) caused by extrapulmonary disease.Methods Forty-four patients of extrapulmonary ARDS, according to crossover design methods, were undergone three RM in different periods, including sustained inflation (SI), increase progressively positive end expiratory pressure (IP), pressure control ventilation (PCV). Heart rate (HR), mean arterial blood pressure (MAP), central venous pressure (CVP), oxygenation index, lung compliance were recorded before and after RM, and were analyzed for statistical analysis. Results Oxygenation index and lung compliance were increased obviously in a short time after RM, improvement of IP method were better more obviously than the other two methods [1 h oxygenation index after RM:227 ± 42 vs 190 ± 19,186 ± 21; lung compliance:(59.4±12.5 ) ml/cm H2O(1 cm H2O = 0.098 kPa) vs (50.1 ± 9.3 ), (49.7 ± 10.6) ml/cm H2O;P＜ 0.05], 2h after RM,there were no statistical difference among the three methods (P＞0.05). After RM,HR and CVPwere increased, MAP was decreased in a short time, changes of SI method were smaller than the other two inethods [10 min HR after RM: (94.0±10.3 ) beats/min vs (116.0 ± 14.8 ), ( 107.0 ± 5.7 ) beats/min; CVP:(13.7±3.1 )cm H2O vs ( 18.4 ± 6.7 ), ( 15.4 ± 2.7 )cm H2O; MAP: ( 87.0 ± 12.1 ) mm Hg( 1 mm Hg = 0.133 kPa) vs (73.0 ± 4.8), (81.0 ± 6.6) mm Hg;P＜ 0.05), 20 min after RM, there were no statistical difference among the three methods (P＞ 0.05). Conclusion When extrapulmonary ARDS undergo RM ,IP method is the most effective on increasing oxygenation index and lung compliance, SI method has the smallest side effect on hemodynamics.

Objective To study the protective effect of normothermic ex vivo perfusion to prevent donor-lung injury.Method After being flushed with perfadex solution through the pulmonary artery and vein,the donor lungs were divided to control group (preserved with 4℃ cold static preservation,n =8) and experimental group (preserved with ex vivo oxygenated blood continuous perfusion,n =8).Pulmonary function indexes,including pulmonary vascular resistance (PVR),lung ventilation resistance(LVR),the left inferior pulmonary vein(LIPV) blood PO2,and lung water content,were evaluated.Lung injury were studied by light microscopic observation and detecting the expression of proimflammatory factor IL-1β was detected.Result (1) Lung function evaluation:in both group,PVR,LVR and lung water content gradually increased,LIPV PO2 gradually declined;But in the same time point PVR and LVR in group were were significantly less than in control group (P＜0.05),LIPV PO2 in experimental group were were significantly more than in control group(P＜0.05).(2)Lung injury evaluation:Lung tissue edema classification in both group were significantly higher than in normal lung(P＜0.05),but classification in experimental group were significantly lower than in control group(P＜0.05).The expression of IL-1β in experimental group (0.422 ± 0.132) were significantly lower than in control group(0.578 ± 0.163,P＜0.05).Conclusion Ex vivo oxygenated blood continuous perfusion without ventilator is a feasible technique for lung preservation.It ameliorates hypothermic time-dependent ischemic injury.But further systems evaluation in complete physiologic condition is necessary.

15-20 years accounted for 11%,12%,14% and 10% , respectively. 260 patients had grade 3 and 4 other injuries, including 55 skin, 79 muscles/soft tissue, 36 mucosa, 79 xerostomia and 11 trismus. Among 320 patients who suffered from caries of teeth, it involved all teeth in 192 patients. Two patients had mandible necrosis. 225 patients had decline of hearing. Among 672 ears in 336 patients,194 ears had severe deafness. The overall side reaction occurrence rate was 84.5%. Conclusions Different late side reactions do exist in nasopharyngeal carcinoma patients(84.5%) with long-term survival after radiotherapy, and some patients suffer side reactions so serious as to affect their quality of life. Cranial nerve injuries are not rare, and it may occur anytime after radiation, but it dose not stop as the patients survive along.

7000?cGy). The cumulative incidence of cranial nerve Ⅸ-Ⅻ palsies increased in patients with advanced N stage. Patients in the first group of treatment field had the highest risk to progress cranial nerve Ⅸ-Ⅻ palsies, followed by the second group, and the third group had the lowest risk. Only 1 in 34 patients with brachytherapy developed cranial nerve palsy. Conclusions Our retrospective data show that the radiation-induced cranial nerve palsy is a common complication in NPC patients after radiotherapy and the incidence seems to increase with the duration of the follow-up. Factors that potentially affect the injury of cranial nerve Ⅰ-Ⅶ and Ⅸ-Ⅻ are different, because of the different anatomy. Controlling the doses to the nasopharyngeal region and using faciocervical fields may help to lower the incidence of cranial nerve palsy.

Objective To investigate the effectiveness of heart valve replacement in the same period of radiofrequency ablation in the treatment of atrial fibrillation.Methods Eighty-six patients with atrial fibrillation underwent heart valve replacement in the same period of bipolar radiofrequency ablation system according to the maze heart valve replacement operation principle.And optimized the operation method.Results No death occurred during operation.The average ablation time was (23 ± 8) minutes with a range of 16-56 minutes.Sinus rhythm of the heart was restored after surgery in all patients (100％).The long-term success rate was 98.8％ (85/86).Conclusion Our optimization of heart valve replacement in the same period of radiofrequency ablation enhanced the success rate of the operation,simplified the procedures,meanwhile it might need widely application clinically.

Purpose: Simulating calculation the dose distribution of the total body irradiation (TBI) with three dimension treatment planning system(3D-TPS ). Materials and Methods: For TBI, the source skin distance(SSD) is 380 cm, field size is 40 cm × 40cm, and collimator angle is 45°. The percent dose depth (PDD) and onset axis ratio (OAR) of the linac accelerator is measured with the big water phantom self-made. In the same radiation condition, the PDD and OAR of water which is simulated calculation with the 3D-TPS is compared with the measurement results to confirm whether the 3D-TPS can calculate the TBI dose distribution. The dose distribution of the human phantom is calculated with 3D-TPS, which is compared and confirmed with the film and TLD measurements. Results: The maximum error of PDD and OAR in the water phantom between the measurements and calculations of 3D-TPS are 3% and 6%. The calculation results of the 3D-TPS is according with the measurement results of the film and TLD approximately. Conclusions: 3D-TPS could simulate calculation the dose distribution for TBI accurately. It is possible to improve more uniform dose for TBI with corresponding compensator for specific patient.

Objective To establish the methods of three-dimensional eonformal(3DCRT) and intensity-modulated radiotherapy(IMRT) for whole pelvic irradiation in post-hysterectomy cervical carcinoma, And to optimize the methods for clinical practice. Methods Between 2004 and 2005,10 patients with cervical carcinoma who underwent hysterectomy with high risk of recurrence were selected for this study. The following observations and measurements were used for the study: Set-up errors with supine or prone position were measured to determine appropriate immobilization position. Influence of full and empty bladder on irradiated normal tissue volume was measured. Treatment errors were detected and CTV/PTV were then delineated. 3DCRT and IMRT planning and comparison were applied. Results The set-up error was within 5 mm of three dimensions in prone position and more than 5 mm in supine position, the difference of which was statistically significant. The percentage of irradiated volume of the bladder and bowel was smaller when the bladder was full comparing with empty bladder. In prone position and with full bladder,portal films showed the movement of isocenter in three directions. The total uncertainty was [7.4±1.6]mm. For 95% confidence interval,the margin from CTV to PTV was 1 cm. CIPTV for 3,4,5,and 6 fields 3DCRT was 0.46,O. 67, O. 68, and O. 68, respectively. When beyond 4 fields, the advantage of adding fields was not significant.Four fields planning was feasible for clinical practice. CI for 5,7,9,11 ,and 13 fidds IMRT was 0.75,0.83, 0.84,0.85 ,and 0.85 ,respectively. When beyond 9 fields,the advantage of adding fields was not significant. Nine fields planning was feasible for clinical practice. Conclusions For whole pelvic radiotherapy for post-hysterectomy cervical carcinoma,prone position was better than supine position for immobilization due to smaller set-up errors. The full bladder is recommended during radiotherapy, planning,For clinical practice,4 fields planning is feasible in 3DCRT while 9 fields planning is feasible in IMRT.