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Objective:To investigate the clinic opathological features, treatment and prognosis of children newly diagnosed with ependymoma.Methods:Clinical data of 127 pediatric ependymoma (EPN) patients (0-16 years old) treated with tumor resection and postoperative radiotherapy at Xinhua Hospital Affiliated to Shanghai Jiao Tong University between 2001 and 2021 were retrospectively analyzed. Among them, 53 children were female and 74 were male. Local control (LR), event-free survival (EFS) and overall survival (OS) rates were analyzed by Kaplan-Meier method. The relationship between clinic opathological factors and clinical prognosis, and the effect of treatment on clinical prognosis of patients were analyzed by Cox proportional hazards model.Results:At a median follow-up time of 29 months (3-251 months), the 3-year OS and EFS rates were 89.5% and 71.5%, respectively. For patients undergoing incomplete resection followed by postoperative adjuvant radiotherapy, the 3-year LR, OS and EFS rates were 78.3%, 65.8% and 85.7%, respectively. A total of 43 children were aged <3 years old when diagnosed and 84 aged ≥3 years old. The interval time between surgery and radiotherapy in children aged <3 years old was 91 d, and 35.5 d in those aged ≥3 years old ( P<0.001). For patients <3 years old, the median EFS was 90 months when initiating radiotherapy within ≤70 d after surgery, compared to 43 months for those who initiated radiotherapy at >70 d after surgery ( P=0.053). According to fifth edition of the WHO classification of tumors of the central nervous system (WHO CNS5), 39 children were classified as posterior fossa ependymoma group A (PFA group). The OS and EFS rates in the PFA group were significantly less than those in other groups (3-year OS rate were 69.2% vs. 94.6%, P<0.001; 3-year EFS rate were 46.9% vs. 79.1%, P<0.001). In the PFA group, 12 patients received postoperative adjuvant chemotherapy, 14 did not receive chemotherapy, and whether chemotherapy was given was unknown in 13 cases. No significant differences were observed in OS and EFS between patients treated with and without chemotherapy ( P=0.260, P=0.730). Univariate Cox analysis showed that tumor location and WHO CNS5 molecular classification were significantly associated with EFS, and WHO CNS5 molecular classification was significantly correlated with OS. Multivariate Cox analysis showed that tumor location in the posterior fossa was an independent risk factor for EFS ( HR=2.72, 95% CI=1.1~6.71, P=0.03). Conclusions:Patients newly diagnosed with pediatric ependymoma can obtain favorable survival after surgery combined with postoperative adjuvant radiotherapy. Patients with residual tumors can achieve favorable LC and survival after postoperative adjuvant radiotherapy. Delaying of radiotherapy tends to lead to poor survival for patients aged <3 years old when diagnosed. Children in the PFA group obtain worse prognosis compared to their counterparts in other groups. The tumor location in the posterior fossa is an independent risk factor for pediatric ependymoma.
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Objective:To evaluate the medium and long-term clinical efficacy of the treatment of lumbar degenerative diseases in Dynesys dynamic internal fixation combined with decompression.Methods:From March 2008 to March 2015, 145 patients (84 males and 61 females, mean age 55.9±7.1 years old) with symptoms of lumbar degenerative diseases (69 lumbar disc herniation, 53 lumbar spinal stenosis and 23 I grade lumbar degenerative spondylolisthesis) were treated by the lumbar discectomy using Dynesys dynamic internal fixation combined with decompression. The clinical symptoms before and after surgery were assessed by visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) and Oswestry disability index (ODI). Lumbar lateral radiographs were used to measure the height of intervertebral space between the surgical segment and the adjacent segment. The range of motion (ROM) between the surgical segment and the adjacent segment was measured by lumbar dynamic position X-ray. Surgical and adjacent segments degenerative were classified according to the Pfirrmann grade classification.Results:The VAS score, ODI and JOA score of lower back and lower limbs in patients with lumbar disc herniation were improved from 6.6±1.7, 7.1±1.4, 63.1%±10.2%, 12.5±2.4 preoperatively to 2.6±1.0, 2.8±0.9, 30.9%±9.8%, 22.4±2.1 at the latest follow-up. The differences were statistically significant. The VAS score, ODI score and JOA score of lower back and lower limbs in patients with lumbar spinal stenosis were improved from 6.3±2.2, 6.9±1.3, 63.4%±8.5%, 12.8±2.7 preoperatively to 2.4±1.2, 2.8±1.0, 35.1%±12.0%, 22.2±2.2 at the latest follow-up. The differences were statistically significant. The VAS score, ODI score and JOA score of lower back and lower limbs in patients with I degree lumbar degenerative spondylolisthesis were improved from 5.7±2.3, 6.7±0.9, 65.7%±10.0%, 12.5±2.7 preoperatively to 2.2±1.2, 2.7±1.1, 37.0%±11.8%, 22.4±2.6 at the latest follow-up. The differences were statistically significant. Comparing to preoperational value, the height of the operative segment and caudal intervertebral space were decreased at the 1 year postoperatively and last follow-up. But the difference was not significant. As for cranial adjacent segment, the height of intervertebral space preoperatively was decreased from 12.1±1.9 mm preoperatively to 11.7±1.6 mm at 1 year postoperatively, and to 11.3±1.8 mm at the latest follow-up. The difference between them was statistically significant ( F=6.46, P=0.001). The ROM of surgical segments was decreased from 7.6°±2.2° preoperatively to 5.5°±1.6° at 1 year postoperatively, and to 2.9°±1.4° at the latest follow-up. The difference between them was statistically significant ( F=267.9, P<0.001). Conversely, the ROM of cranial and caudal segments was increased from 8.2°±2.4°, 6.5°±1.6° preoperatively to 9.1°±2.1°, 7.1°±1.9° at 1 year postoperatively, and to 10.6°±2.5°, 7.2°±1.8° at the latest follow-up. The difference between them was statistically significant ( F=38.66, 3.81, P<0.001, 0.023). At the latest follow-up, 120 (51.9%) adjacent segments were to be defined adjacent segment degeneration which includes 103 radiological adjacent segment degeneration and 17 symptomatic adjacent segment degenerations. Conclusion:Dynesys dynamic internal fixation combined with decompression could achieve satisfying mid- and long-term therapeutic effect in the treatment of lumbar degenerative diseases. The ROM of surgical segments decreased with time, although part of the ROM was still retained at the latest follow-up. However, it does not seem to avoid the degeneration of adjacent segment.
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Objective:To evaluate the feasibility of C 2 laminar screw fixation with double holes, and to explore a new method to judge the safe position of screws during operation. Methods:There were 22 axial specimens, 11 males and 11 females, aged from 26-69 years (mean 47.2 years). The Dicom format of Cervical spine specimens were obtained by CT scanning. It was transferred into the Mimics software for reconstructing the three-dimensional cervical spine model. The central horizontal plane of the axial lamina was cut off as the measuring plane by using the segmentation function. The cortical bone of the start and end lamina was removed naming hole 1 and 2. The distances of D1 and D2 are measured at the trajectory positions of maximum safe ventral inclination, parallel, or maximum safe dorsal inclination, with each entry point (A, M, P). A paired comparison was performed for each group.Results:Forty-four groups of parallel, introversion and extroversion screw path parameters were obtained from 22 axial specimens, and there was no significant difference between the left D1 and D2 groups in each group A, M, P [group A: 3.72±0.95 mm, 3.37±1.24 mm; group M: 2.29±0.72 mm, 1.94±0.58 mm; group P: 1.17±0.44 mm, 0.86±0.69 mm] ( t=1.051, 1.776, 1.777; P>0.05), while the right D1 and D2 had statistical significance[group A: 4.44±1.20 mm, 3.36±1.37 mm; group M: 3.01±0.76 mm, 1.97±0.90 mm; group P: 2.06±0.73 mm, 1.00±0.87 mm]( t=2.781, 4.141, 4.378; P<0.05). In introversion, there was no significant difference in left D1 and D2 in group M [3.11±0.92 mm, 3.79±1.36 mm] ( t=1.942, P=0.058), and was no significant difference in right D1 and D2 in group M [3.79±1.20 mm, 3.69±1.55 mm] ( t=0.239, P=0.812). In group P, the left D1 and D2 were compared, and the results had statistically differences [2.67±0.77 mm, 4.25±1.39 mm] ( t=4.644, P=0.000). In group P, the right D1 and D2 were compared, and the results were statistically different [2.57±1.14 mm, 3.94±1.53 mm] ( t=3.368, P=0.001). In extroversion, the left D1 and D2 in group A and M were compared, and the results had statistically differences [group A: 3.44±1.05 mm, 1.22±0.71 mm; group M: 2.26±0.73 mm, 0.90±0.75 mm] ( t=8.215, 6.095; P<0.05); the results of group A and group M were statistically different between groups of D1 and D2 on the right side[group A: 4.56±1.51 mm, 1.48±0.97 mm; group M: 2.96±1.12 mm, 1.06±0.75 mm] ( t=8.049, 6.611; P<0.05). Conclusion:The double hole screw technique of the C 2 lamina can judge the safe position of the screw in the operation without additional fluoroscopy.
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Objective To preliminarily evaluate the safety of the coplanar template-assisted 192Ir hypofractionated stereotactic ablative brachytherapy (SABT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC),and assess the effect of template-assisted technology upon the accuracy of SABT by comparing the consistency of dosimetric parameters between preoperative and operative plans.Methods Fifteen patients histologically confirmed with LA-NSCLC (stage ⅡB-ⅢA) were recruited and received the template-assisted SABT delivered in a risk-adapted fractionation (30 Gy/1F).Preoperative planning,template-assisted needle implantation,operative planning and implementation were performed in all patients.Dosimetric results of preoperative and operative plans were statistically compared by assessing the dosimetric parameters of gross tumor volume (HI,CI,D90,V100 and V150) and organ at risk (V5,V20 and mean dose of bilateral lung,D2cc of spinal cord.The incidence of perioperative complications of SABT was recorded.The safety and feasibility of SABT were evaluated.Results Slight changes were noted in terms of target dose and irradiated dose to the lung between preoperative and operative plans without statistical significance (both P＞0.05).No severe adverse events,such as severe pneumothorax,hemothorax and hemoptysis were observed.Conclusions Application of the template-assisted SABT can enhance the accuracy of implantation,maintain the consistency of the dosimetric parameters between the preoperative and operative plans and guarantee the clinical efficacy.
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Objective@#To preliminarily evaluate the safety of the coplanar template-assisted 192Ir hypofractionated stereotactic ablative brachytherapy (SABT) in patients with locally advanced non-small cell lung cancer (LA-NSCLC), and assess the effect of template-assisted technology upon the accuracy of SABT by comparing the consistency of dosimetric parameters between preoperative and operative plans.@*Methods@#Fifteen patients histologically confirmed with LA-NSCLC (stage ⅡB-ⅢA) were recruited and received the template-assisted SABT delivered in a risk-adapted fractionation (30 Gy/1F). Preoperative planning, template-assisted needle implantation, operative planning and implementation were performed in all patients. Dosimetric results of preoperative and operative plans were statistically compared by assessing the dosimetric parameters of gross tumor volume (HI, CI, D90, V100 and V150) and organ at risk(V5, V20 and mean dose of bilateral lung, D2cc of spinal cord. The incidence of perioperative complications of SABT was recorded. The safety and feasibility of SABT were evaluated.@*Results@#Slight changes were noted in terms of target dose and irradiated dose to the lung between preoperative and operative plans without statistical significance (both P>0.05). No severe adverse events, such as severe pneumothorax, hemothorax and hemoptysis were observed.@*Conclusions@#Application of the template-assisted SABT can enhance the accuracy of implantation, maintain the consistency of the dosimetric parameters between the preoperative and operative plans and guarantee the clinical efficacy.
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Objective To investigate the clinical efficacy of posterior lumbar interbody fusion and internal fixation for the treatment of lumbar spinal stenosis with redundant nerve roots (RNRs).Methods A retrospective case series study was performed on the clinical data of 23 cases of lumbar spinal stenosis with RNRs from January 2009 to December 2014.This study involved 10 males and 13 females,with an average age of 48.4 years(range,38-58 years).The course of disease averaged 28.1 months(range,2 months-7 years).There were seven patients with single segment of stenosis,12 patients with two segments of stenosis,and four patients with three segments of stenosis.RNRs diagnostic criteria:in the sagittal section of the MRIT2 image of lumbar spine,the cauda equina nerve root in the dural sac was circular,tortuous and twining.MRI information was collected and analyzed by three double-blind radiologists,respectively.RNRs were determined based on the unanimous consent of all the three doctors.All patients underwent posterior discectomy,spinal canal decompression,interbody fusion,and internal fixation after admission.The operation time,intraoperative blood loss,and postoperative complications were recorded.The visual analogue scale (VAS),Oswestry disability index (ODI),and Japanese Orthopedic Association (JOA) score were used to evaluate the back pain and leg pain before operation and 3 months after operation.Fischgrund standard was used for the overall efficacy evaluation.Results All patients were followed up for 12-30 months (mean,23.3 months).The operation time was (130.0 ± 23.2) minutes,and the intraoperative blood loss was (513.0 ± 165.0) ml.MRI was reviewed 1 week after operation,and the result showed that redundancy of cauda equina disappeared.Preoperatively,the scores of back pain VAS,leg pain VAS,ODI and JOA were (6.3± 0.8) points,(6.8 ±0.9)points,(46.7±2.5)points and (10.3 ±2.8)points,respectively.At 3 months postoperatively,the scores were (1.4 ± 0.5) points,(1.8 ± 0.7) points,(11.9 ± 2.1) points,and (25.3 ± 1.8) points,respectively (P ＜ 0.05).In terms of the efficacy,17 cases were excellent,four good,and two fair,with an excellent and good rate of 91％.At 12 months after operation,the CT scan showed no screw rupture or cage dislocation,with bony union seen between the vertebrae.Conclusion Posterior lumbar interbody fusion and internal fixation can help relieve the back and leg pain and eliminate redundant nerve roots in patients with lumbar spinal stenosis with RNRs.
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Objective To compare the clinical efficacy and fusion rate of unilateral and bilateral C1 and C2 pedicle screw fixation of unstable Jefferson fractures.Methods This retrospective casecontrol study enrolled 22 patients with unstable Jefferson fractures admitted between April 2012 and May 2015.There were 18 males and four females,with the mean age of 52.9 years (range,35-67 years).Mean preoperative visual analogue scale (VAS) was 6.09 points (range,4-8 points).According to the American spinal injury association (ASIA) classification,two patients were rated grade D and one patient grade C.Mean Japanese orthopedic association (JOA) score was 12.3 points.Bilateral C1 and C2 pedicle screw fixation was performed for 15 patients (bilateral group).Advantage side unilateral C1 and C2 pedicle screw fixation was performed for seven patients with extremely unstable fracture or narrow pedicle (unilateral group).Operation time,blood loss and surgical complications were recorded.VAS was used to evaluate the improvement of neck pain after operation.ASIA classification and JOA score were used to assess nerve function recovery.Atlanto-dental interval (ADI),srew position and bone fusion were evaluated after operation.Results All patients successfully completed the operation.Operation time was (119.5 ±21.2)min,and blood loss was (280.1 ±83.1)ml.A total of 74 screws were placed and CT scan showed satisfactory position of the screws.No complications were noted either during the operation or after surgery.All patients were followed up for mean 20.7 months (range,13-33 months).VAS was improved in both groups after operation (P ＜ 0.01),and there was no significant difference between the two groups (P ＞ 0.05).Two patients with ASIA grade D in bilateral group were improved to ASIA grade E after operation.One patient with ASIA grade C in unilateral group was improved to ASIA grade D after operation.JOA score increased to mean 15.7 points at last follow-up.ADI were decreased in both groups after operation(P ＜0.05),but there was no significant difference between the two groups (P ＞ 0.05).All patients had bony fusion 6 months after operation,with similar fusion rate between the two groups (P ＞ 0.05).Conclusion Advantage side unilateral screw fixation can be used for the patients with bilateral C1 and C2 pedicle screw fixation failure,for the technique can improve cervical pain and provide relatively high stability and fusion rate.
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Objective To explore an ideal screw insertion point and optimal trajectory for anterior axis pedicle screw (AAPS) so as to provide an anatomical basis for AAPS placement.Methods CT scan of the cervical spine was performed for 40 healthy Chinese adults.Then,the CT data were imported into the Mimics software to reconstruct the three-dimensional images of the axes.The data were divided into two groups according to the gender.The following data were measured:pedicle centerline minimal diameter on both left and right sides,pedicle axial length,the distance between entrance point and upper endplate,the distance between entrance point and median sagittal plane,the distance between entrance point and peak of crista lambdoidalis of C2 vertebral body,extraversion angle and sagittal angle.The screw fixation parameters for AAPS were measured using the Mimics software.Results There was no statistical difference between the left and right sides as well as between the genders (P ＞ 0.05).The entrance point for insertion of AAPS was recommended to be on (4.39 ± 0.67) mm from the upper endplate,and on (3.95 ± 0.44) mm from the median sagittal plane.The ideal pedicle axial length was (34.15 ± 2.93) mm,and the pedicle centerline minimal diameter was (7.04 ± 0.87) mm.The distance between the entrance point and the peak of crista lambdoidalis of C2 vertebral body was (1.45 ± 0.19) mm.The ideal extraversion angle was (30.80 ± 2.79) °,and the ideal sagittal angle was (36.35 ± 3.26) ° . Conclusion The ideal insertion pathway of AAPS placement can avoid spinal canal,foramen intervertebrale and other important anatomical structure,which is feasible in regard of anatomy.The insertion point can refer to the peak of crista lambdoidalis of C2 vertebral body.However,AAPS placement should be individualized in term of its anatomy variability.
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Objective To explore the relationship between the overlap volume of organ at risk (OAR) and target (Voverlap) and the mean dose to OAR (DmOAR) in intensity-modulated radiotherapy (IMRT).Methods Fifty randomly selected patients undergoing IMRT for nasopharyngeal carcinoma (NPC) and an equal number of patients undergoing radical IMRT for cervical cancer in our hospital were enrolled as subjects.The relationship between Voverlap and DmoAR in IMRT was analyzed.The Matlab software was used to generate function to fit the relationship between Voverlap and DmOAR for different OARs.Results The Voverlap varied among patients with NPC or cervical cancer.The ratio of Voverlap to the volume of OAR (VOAR) was positively correlated with the ratio of DmOAR to the prescribed dose (Dp) (all P=0.01).A function was generated to fit the correlation between Voverlap/VOAR ratio and DmOAR/Dp ratio.Conclusions In IMRT,patients have different Voverlap/VoAR ratios due to varicd target volume,disease stages,OAR filling status,and OAR volume.As criteria for plan verification,a specific DmOAR value for each OAR should be calculated before radiotherapy planning based on the corresponding correlation function and the Voverlap/VoAR ratio with a fixed dose prescription.It can be used to reduce the subjective influence on the optimization of radiotherapy planning.
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Objective To compare the clinical effects of posterior pedicle screw fixation combined with anterior monosegmental or bisegmental fusion reconstruction in patients with unstable Denis type B thoracolumbar burst fractures.Methods A retrospective case-control analysis was made on 62 cases of Denis type B thoracolumbar burst fractures treated from June 2010 to June 2014.There were 51 males and 11 females,aged 19-55 years (mean,35.1 years).The injury causes included fall from height in 32 cases,traffic accidents in 24,hit by heavy objects in 6.Fifty cases were with monosegmental burst fractures,and 12 with monosegmental burst fractures combined with other vertebral compressive fractures.The burst fracture levels were at T~in 8 cases,T12in 20,L1 in 24,L2 in 6,and L3 in 4.According to the different surgical methods,the patients were divided into two groups:Group A (n =30,treated with posterior pedicle screw fixation combined with anterior monosegmental fusion reconstruction) and Group B (n =30,treated with posterior pedicle screw fixation combined with anterior bisegmental fusion construction).The operation time and intraoperative blood loss were compared between the two groups.Visual analogue scale (VAS),Oswestry disability index (ODI),and Frankel scale of neurologic function were compared at last follow-up.The changes of anterior height of fracture vertebrae and Cobb angle of the two groups were also compared preoperatively,postoperatively and at last follow-up.Implant looseness and breakage,titanium mesh tilt,and bone fusion were recorded postoperatively.Results All patients were followed up for 18-24 months (mean,20.8 months).The operation time and blood loss in Group A was (208.2 ± 15.6) min and (598.3 ± 55.3) ml,respectively.The operative time and blood loss in Group B was (260.1 ± 17.4)min and (662.2± 58.3)ml,respectively.There were significantly statistical differences between two groups in operation time and blood loss (P ＜0.05).There were no statistical differences between two groups in terms of Cobb angle restoration and fracture height restoration rate after surgery,Cobb angle loss and fracture vertebral body front height loss rate at final follow-up (P ＞ 0.05).At the final follow-up,VAS in Group A was (2.5 ± 0.8) points,less than (3.2 ± 1.1) points in Group B (P ＜ 0.05);ODI in Group A was (20.3 ± 5.8) points,less than (28.2 ± 5.1) points in Group B (P ＜ 0.05).Frankel scale was improved to some degree after operation (P ＜ 0.05).One case did not achieve bone fusion in Group A versus three cases in Group B (P＜0.05).No implant Loosening,titanium mesh tilt or settlement was found in Group A,while there were eight cases of titanium mesh tilt or settlement in Group B (P ＜0.05).Conclusions For unstable Denis type B thoracolumbar burst fractures,posterior pedicular fixation combined with anterior monosegmental fusion or bisegmental fusion can achieve equal clinical effects.However,posterior pedicular fixation combined with anterior monosegmental fusion can have less injury,higher bone fusion rate,better function restoration,and less incidence of complication.
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Objective To analyze the effect of needle arrangement on the lung dose in interstitial brachytherapy for lung cancer. Methods For 15 patients undergoing interstitial brachytherapy for lung cancer, a virtual radiotherapy plan in which needle arrangement was not restricted by the ribs was designed and compared with the original plan. For the two plans, V5, V20, V30, and mean lung dose(MLD)of the whole lung were determined when the prescribed doses were 10,30, 60, and 120 Gy, respectively. The data were analyzed by Wilcoxon signed-rank test. Results The lung V5,V20, V30, and MLD were significantly smaller in the virtual plan than in the actual plan(all P<0.05). Conclusions Irregular needle arrangement prevents a further reduction in the lung dose in interstitial brachytherapy for lung cancer. In the implantation surgery, therefore, the needles should be arranged as regularly as possible.
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Objective To investigate the clinical outcomes of pedicle screw fixation assisted with the 3D printing positioning guide template for treatment of unstable atlas fractures.Methods A retrospective case series review was made on 10 patients with unstable atlas fractures undergone direct posterior C1 pedicle screw fixation assisted with the 3D printing drill guide template from September 2012 to May 2015.There were 7 males and 3 females,with a mean age of 52.6 years (range,23-75 years).All patients complained of neck pain,stiffness and decreased range of motion without neurologic deficit.Preoperative skull traction was used routinely.After the three-dimension reconstruction of cervical vertebrae,ideal trajectory for C1 pedicle screws was designed with a complementary basal template for posterior surface of atlas corresponding anatomical structure.Then the drill guide template was materialized in a rapid prototyping machine and used during operation.Start point and direction of the ideal and actual trajectories were measured after matching the position of the pre-and post-operative patients' cervical spine.Safety of pedicle screw fixation was assessed in the transverse and sagittal planes of CT scan.Operation time and blood loss were recorded.Visual Analogue Scale (VAS) of neck pain was recorded before operation and 3 months after operation.Clinical efficacy,fracture reduction,stability and surgical complications were reviewed at the follow-up.Results A total of 20 screws were inserted safely.No significant differences existed in deviation of entry point and direction between ideal and actual trajectories (P ＞0.05).Operation time was 60-90 min (mean,75 min) and intraoperative blood loss was 110-300 ml (mean,160 ml).No spinal cord or vertebral artery injury was noted during operation.All patients were followed up for 12-36 months (mean,20.5 months).VAS was improved from preoperative 7.3 (6.3-9.5) points to 1.4 (0.3-2.5) points 3 months after operation (P ＜ 0.05).All patients had normal range of motion of the cervical spine 3 months after operation.Bony fusion was achieved 6 months after operation.At the follow-up,good cervical alignment was maintained with no instrument failure and C1.2 instability.Conclusion For treatment of unstable atlas fractures,direct posterior C1 pedicle screw fixation assisted with the 3D printing drill guide template can improve the precision of screw placement,reduce complications,and preserve the function of the occipital-atlantoaxial junction.
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Objective To study the iso-center point coincidence of two accelerators with treatment planning system (TPS) based on γ passing rates of intensity-modulated radiotherapy (IMRT) plan verification.Methods Twenty-one IMRT plans were verified by Varian accelerator and twenty by Elekta accelerator with a gamma criterion of 3 mm/3％.The passing rates were measured when the iso-center point of TPS had-2,-1,0,1,and 2 mm shift in the x or y direction.A binomial curve of γwas fit to figure out the values of the two accelerators on the x and y axes when γ value reached the maximum.The γ pass rate difference was analysed by x2 test.Results The mean values of γ-2,γ-1,γ0,γ1,and γ2 in the x direction were (92.56±3.27) ％,(96.53± 1.82) ％,(96.13± 1.41) ％,(90.14± 2.87) ％,and (82.28± 4.69) ％ for Varian accelerator,and (94.82± 2.04) ％,(97.05± 2.02) ％,(98.38± 1.33) ％,(97.96± 1.44) ％,and (94.49±2.34)％ for Elekta accelerator.There was no significant difference in the mean value of γ0between the two accelerators (P=0.332).When γvalue reached the maximum,the values on the x and y axes were0.65 and-0.30 mm for Varian accelerator and 0.01 and 0.30 mm for Elekta accelerator,respectively.Conclusions In the same TPS,different accelerators have different degrees of coincidence of the actual field center point with the iso-center point of TPS,to which more attention should be paid in clinical practice.
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Objective To determine the treatment options for teardrop fracture of the axis and discuss the treatment efficacy.Methods Nineteen patients with teardrop fracture of the axis treated from March 2003 to June 2013 were retrospectively reviewed.Teardrop fracture of the axis accounted for 3.9％ of the cervical injuries and 11.4％ of the axis fractures over the same period.There were 15 males and 4 females,at age range of 21-56 years (mean,37.8 years).Injury was caused by traffic accidents in 12 patients,falls in 6,and hit from heavy objects in 1.Cervical imaging examinations (X-ray,CT and MRI) were performed on admission.Thirteen patients were immobilized for 3 to 6 months with the Halovest device,and six patients underwent anterior cervical surgery.No patients had neurologic deficit [American Spinal Injury Association (ASIA) grade E].Visual analogue scale (VAS),implant failure and bone fusion were recorded after operation.Results All patients were followed up for 12-18 months (mean,15.6 months).At the final follow-up,no implant loosening or breakage happened and 18 patients achieved bone union.Neck mobility returned to normal,which showed VAS improved from (7.5 ± 1.2) points to (3.1 ± 1.5) points.ASIA grade E remained in 18 patients,and one patient were progressed to grade D.Conclusions Teardrop fracture of the axis is rare cervical injury,and can be treated conservatively in most cases.However,surgery is often necessary when imaging findings suggest the existence of instability.
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Objective To evaluate the effect of type Ⅱ odontoid fracture,type Ⅰ Hangman fracture,C2-C3 disc injury on stability of C1-C2 and C2-C3 segments and investigate the clinical significance.Methods Ten fresh-frozen cadaveric cervical specimens (5 men and 5 women; 25-45 years of age,mean 35.7 years) were selected to test the stability of C1-C2 and C2-C3 segments in the settings of intact condition (control group),type Ⅰ Hangman fracture,type Ⅱ odontoid fracture,type Ⅰ Hangman fracture + type Ⅱ odontoid fracture,type Ⅰ Hangman fracture + type Ⅱ odontoid fracture + C2-C3 disc injury.Range of motion (ROM) and neutral zone (NZ) of those segments were measured.Results Compared with the intact condition,type Ⅰ Hangman fracture produced no significant variations in C1-C2 ROM in all loading modes and C2-C3 ROM during left and right lateral bending; type Ⅱ odontoid fracture produced no significant variations in C2-C3 ROM in all loading modes and C1-C2 ROM during left and right rotation; type Ⅰ Hangman fracture + type Ⅱ odontoid fracture revealed no significant variations in C1-C2 ROM during left and right rotation and C2-C3 ROM during extention; type Ⅰ Hangman fracture + type Ⅱ odontoid fracture + C2-C3 disc injury produced no significant variations in C1-C2 ROM during left and right lateral bending and extension-flextion and C2-C3 ROM in all loading modes (P ＜ 0.05).Conclusions Type Ⅰ Hangman fracture can reserve C1-C2 segmental left and right rotation and extension-flextion; type Ⅱ odontoid fracture can reserve C1-C2 segmental left and right lateral bending and extension-flextion; type Ⅰ Hangman fracture + type Ⅱ odontoid fracture + C2-C3 disc injury can reverse atlantoaxial rotationary stability and C1-C3 segmental stability in all directions.This study provides the biomechanical basis for clinical treatments and the related researches of internal fixation.
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<p><b>OBJECTIVE</b>To explore the ideal screw entry point and optimal trajectory for anterior C1 lateral mass screw internal fixation, and provide an anatomical basis for the technique of anterior C1 lateral mass screw placement.</p><p><b>METHODS</b>A radiographic analysis of the anatomy of the C1 lateral mass using Computed tomography, CT scan was performed in cervical spine of 56 healthy Chinese adults (28 males, 28 females; mean age, 36.5 years; age range, 18-55 years), by using the Mimics software to reconstruct the 3-D morphology of C1 lateral mass and measuring the inside, middle and outside effective height of the C1 lateral mass in front and back. Measuring the C1 lateral mass safe width with different extraversion angles range from 0° to 30° with a uniform interval of 5°, to find out the ideal extraversion angle. Measuring the range of sagittal angle, to find out the ideal sagittal angle.</p><p><b>RESULTS</b>The inside (H1), middle (H3) and outside (H5) effective height of the C1 lateral mass in front is 6.67 mm, 12.09 mm, and 17.51 mm, the inside (H2), middle (H4) and outside(H6) effective height of the C1 lateral mass in back is 8.17 mm, 13.20 mm, and 18.22 mm. When the extraversion angle choose 0°, 5°, 10°, 15°, 20°, 25°, 30°, and δ, the relative results of safe width (SW) of lateral mass were 4.73 mm, 5.36 mm, 5.90 mm, 6.33 mm, 6.44 mm, 5.70 mm, 4.38 mm, 6.95 mm averagely. The mean distance along the atlas anterior surface between the anterior tubercle and the screw entry point was 12.80 mm, the mean distance from the inferior border of the lateral mass to the screw entry point was 6.87 mm. The range of sagittal angle is 24.22° (-17.74°∼6.48°) .</p><p><b>CONCLUSIONS</b>The ideal extraversion angle was 21.14°. The mean distance along the atlas anterior surface between the anterior tubercle and the screw entry point was 12.80 mm. The mean distance from the inferior border of the lateral mass to the screw entry point was 6.87 mm. The ideal sagittal angle is -5.63°. These measurements may facilitate anterior C1 lateral mass screw fixation decreasing the risk of injury to the spinal cord, vertebral artery, and internal carotid artery theoretically. Delineating the individual anatomy in each case with CT scan before surgery is recommended.</p>
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Young Adult , Bone Screws , Carotid Artery, Internal , Diagnostic Imaging , Cervical Atlas , Cervical Vertebrae , Diagnostic Imaging , General Surgery , Fracture Fixation, Internal , Image Processing, Computer-Assisted , Plastic Surgery Procedures , Tomography, X-Ray Computed , Vertebral Artery , Diagnostic ImagingABSTRACT
We applied Demons and accelerated Demons elastic registration algorithm in radiotherapy cone beam CT (CBCT) images, We provided software support for real-time understanding of organ changes during radiotherapy. We wrote a 3D CBCT image elastic registration program using Matlab software, and we tested and verified the images of two patients with cervical cancer 3D CBCT images for elastic registration, based on the classic Demons algorithm, minimum mean square error (MSE) decreased 59.7%, correlation coefficient (CC) increased 11.0%. While for the accelerated Demons algorithm, MSE decreased 40.1%, CC increased 7.2%. The experimental verification with two methods of Demons algorithm obtained the desired results, but the small difference appeared to be lack of precision, and the total registration time was a little long. All these problems need to be further improved for accuracy and reducing of time.
Subject(s)
Humans , Algorithms , Cone-Beam Computed Tomography , Image Interpretation, Computer-Assisted , Imaging, Three-Dimensional , SoftwareABSTRACT
Objective To explore a new method of comparing the references images first to enhance the precision of the central point of the radiation treatment planning(RTP), try to establish a reference standard for this method in the nasopharyngeal cancer(NPC)and carcinoma of utercin cervix in the work of position verification. Methods For 50 RTPs of NPC and 20 RTPs of carcinoma of utercin cervix, the reference-CT-images in set-up and in position verification were compared, and to measure the difference between the two images. Then, in the same way, compare and measure the difference in the central-pointimages. Results For NPC, there was over 90% RTPs in which every difference measured was less than 2 mm;for carcinoma of utercin cervix, over 80% RTPs meet the criterion:the value of △MU1 ' or △MU2' was less than 5 mm and the others are less than 3 mm. Conclusions By comparing the references-CT-images in set-up and in position verification, the precision of the central point of the RTP is enhanced. The marks on the skin become more credible. So, it is feasible to perform the criterions in the work of position verification:for NPC every difference measured is less than 2 mm;for carcinoma of utercin cervix the value of △MU1 ' or △MU2 ' is less than 5 mm and the others are less than 3 mm.
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1H-nuclear magnetic resonance spectroscopy ( 1H-NMRs ) analysis was performed on serum specimens obtained from 60 preoperative patients with esophageal squamous cell carcinoma ( ESCC )and 30 healthy controls, and supernatant from 2 ESCC cell lines Eca-109 and TE-13.The characteristic fingerprint was profiled with 1H-NMRs data in healthy controls.Serum 1H-NMRs from 60 preoperative patients with ESCC were measured and compared with the 1H-NMRs from 30 healthy controls.We found some specific peaks in 1H-NMRs profile of serum specimens from ESCC patients, especially at 1.0-1.2 mg/L and 3.4 - 3.6 mg/L.The results were verified by the 1H-NMRs measurement on the supernatant from 2 ESCC cell lines Eca-109 and TE-3.Our results suggest that this two absorption peaks may be characteristic for ESCC and 1H-NMRs analysis on serum specimens may provide information for early diagnosis of ESCC.