Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective To detect the isocenter of a medical linear accelerator using an optical surface monitoring system (OSMS) combined with a self-made 3D-printed phantom, and compare with the conventional front pointer measurement method. Methods A phantom that could be fixed to the front pointer of the accelerator was fabricated using 3D printing technology. The front pointer method and OSMS were used to detect the rotation isocenter deviations of the accelerator. During the experiments, the collimator, gantry, and couch linear displacement readings were recorded at different angles. We also recorded the measurement time of different surveyors. Results Compared to the front pointer measurement method, the OSMS method showed lower standard deviations. The reductions in standard deviations showed statistical significance in the Lat direction for the collimator rotation isocenter as well as in the Lat and Vrt directions for the gantry rotation isocenter. The mean deviation of Mag values for the collimator rotation isocenter using the OSMS method was 0.50 mm, which was larger than the 0.42 mm using the front pointer method. However, the standard deviation was 0.06 using the OSMS method, which was smaller than the 0.18 using the front pointer method. The mean deviation and standard deviation of Sag values for the gantry rotation isocenter using the OSMS method were 1.03 mm and 0.12, respectively, which were both larger than 0.47 mm and 0.06 using the front pointer method. For the couch rotation isocenter, the mean deviation and standard deviation using the OSMS method were 0.32 mm and 0.04, respectively, which were both smaller than the 0.55 mm and 0.20 using the front pointer method. All surveyors spent less time in isocenter measurements using the OSMS method compared to the front pointer method. Conclusion Compared with the front pointer method, the OSMS method significantly reduces the standard deviation among surveyors, effectively reduces the influence of the angle deviation of the accelerator on the measurement results, reduces detection time, improves detection efficiency, and provides a powerful practical basis for the application of OSMS in detecting the mechanical accuracy of the linear accelerator.

Objective:To reassess the prognostic value of minimal residual disease (MRD) and IKZF1 gene deletions in adults with B-cell acute lymphoblastic leukemia (B-ALL) who received pediatric-specific chemotherapy regimens during the Nanfang Hospital PDT-ALL-2016 trial.Methods:We retrospectively analyzed the prognosis of 149 adult patients with B-ALL who were admitted to Nanfang Hospital from January 2016 to September 2020. Prognostic factors were identified using Cox regression models.Results:The complete remission rate was 93.2% in 149 patients, with a 5-year overall survival (OS) rate of (54.3±5.0) % and a cumulative incidence of relapse (CIR) of (47.5±5.2) %. The Cox regression analysis revealed that MRD positivity at day 45 (MRD 3) after induction therapy was independently associated with relapse risk ( HR=2.535, 95% CI 1.122-5.728, P=0.025). Deletion of IKZF1 gene was independently associated with mortality risk ( HR=1.869, 95% CI 1.034-3.379, P=0.039). Based on MRD 3 and IKZF1 gene status, we categorized adult patients with B-ALL into the low-risk (MRD 3-negative and IKZF1 gene deletion-negative) and high-risk (MRD 3-positive and/or IKZF1 gene wild type) groups. The 5-year OS and CIR rates were (45.5±6.0) % vs (69.4±8.6) % ( P<0.001) and (61.6±8.3) % vs (25.5±6.5) % ( P<0.001), respectively, in the high-risk and low-risk groups, respectively. The multivariate analysis showed that the high-risk group was an independent risk factor for OS ( HR=3.937, 95% CI 1.975-7.850, P<0.001) and CIR ( HR=4.037, 95% CI 2.095-7.778, P<0.001) . Conclusion:The combined use of MRD and IKZF1 gene in prognostic stratification can improve clinical outcome prediction in adult patients with B-ALL, helping to guide their treatment.

Objective:To propose a markless patient setup workflow based on the optical surface monitoring system (AlignRT) and open-face mask immobilization for whole-course head tumor radiotherapy, assess the setup time and repositioning frequency of the proposed workflow, and conduct a comparative analysis of the differences, correlation, and consistency of the setup errors of the AlignRT and cone beam CT (CBCT) systems.Methods:A retrospective analysis was conducted for the data on the errors of 132 fractionated setup based on open-face mask immobilization of 33 head tumor patients. AlignRT-guided markless patient setup workflow was applied throughout the radiotherapy. Meanwhile, the body structures automatically generated by the treatment planning system were used as body references. The 6-degree-of-freedom (6DoF) setup errors (lateral, vertical, longitudinal, rotation, pitch, roll, and yaw directions), setup time, and repositioning frequency of the AlignRT and CBCT systems were recorded and analyzed. The Wilcoxon and Spearman analyses were used to statistically assess the differences and correlation of the setup errors of the two systems. Moreover, the Bland-Altman analysis was employed to evaluate the consistency of the two systems.Results:The 6DoF setup errors of CBCT were within the clinical tolerance (linear motions: -0.30 to 0.30 cm; rotational motions: -2.0° to 2.0°). The setup time and repositioning frequency of CBCT were (98 ± 31) s and 1.51% (2/132), respectively. There was no significant difference in setup errors between the two systems except those in x-axis ( Z = -3.11, P= 0.002), y-axis ( Z = -7.40, P<0.001), and Pitch ( Z= -4.48, P<0.001). There was a significant positive correlation between the setup errors along lateral ( rs = 0.47, P<0.001) and vertical ( rs = 0.29, P = 0.001) directions, rotation (Rtn; rs = 0.47, P<0.001), pitch (Pitch; rs = 0.28, P = 0.001) and roll (Roll; rs = 0.45, P<0.001) of the two systems. The 95% limits of agreement (95% LoA) of 6DoF setup errors were -0.12 to 0.09 cm, -0.07 to 0.17 cm, -0.19 to 0.20 cm, -1.0° to 0.9 °, -1.0° to 1.5°, and -0.9° to 1.0°, respectively. The 95% confidence interval (95% CI) of 95% LoA was -0.14 to 0.11 cm, -0.09 to 0.19 cm, -0.23 to 0.23 cm, -1.2° to 1.1°, -1.2° to 1.7°, and-1.0° to 1.1°, respectively, all of which were within the permissible error ranges. The 6DoF setup error difference of 3.41% (27/792< 5%) was beyond the 95% LoA. The maximum absolute differences of 6DoF setup errors within the 95% LoA were 0.12, 0.16, 0.19 cm, 0.9°, 1.5°, and 1.0°, respectively. Conclusions:The proposed markless setup workflow based on AlignRT combined with open-face mask immobilization for whole-course head tumor radiotherapy exhibits reasonable agreement and consistency with the patient setup using CBCT, with acceptable clinical efficiency. It can be applied to the first radiotherapy and the real-time monitoring of therapy to improve the safety and thus is of value in clinical applications.

BACKGROUND: It remains unclear regarding the difference in bone healing effects after early-stage versus late-stage bone grafting within induced membrane. OBJECTIVE: To investigate the difference in bone healing effects of bone grafting within induced membrane in the repair of bone defects and the major factors that affect bone healing. METHODS: Sixty-three patients with tibial bone defect who received treatment with induced membrane technique during January 2007 to August 2017 in Wuxi People’s Hospital and Wuxi Orthopedics Hospital, China. These patients consisted of 38 males and 25 females and were aged 16-69 years. According to the time of bone grafting within induced membrane after bone cement filling, these patients were divided into an early stage group (n=25, bone grafting in the induced membrane 6-8 weeks after filling bone cement) and a late stage group (n=38, bone grafting in the induced membrane 10-12 weeks after filling bone cement). The healing of bone defect and functional recovery of affected limbs were evaluated. The causes of delayed healing and nonunion were analyzed. This study was approved by the Medical Ethics Committee of Wuxi People’s Hospital and Wuxi Orthopedics Hospital, China (approval No. LW2019001). RESULTS AND CONCLUSION: Bone graft was successfully completed in 63 patients. The induced membrane formed in the early stage group was thin and there were relatively more capillaries, while the induced membrane formed in the late stage group was usually thick and there were relatively few capillaries. All 63 patients were followed up for 16-50 months. In the early stage group, the wound or incision healed at first intention in 22 patients and delayed healing was observed in 3 patients. In the late stage group, the wound or incision healed at first intention in 34 patients, delayed healing was observed in 2 patients, and healing by the second intention was observed in 2 patients. In the early stage group, there was 1 patient developing delayed healing, no nonunion was observed, the clinical healing time was averaged 6.64 (range 5.0-12.0 months) months. In the late stage group, delayed healing occurred in 2 patients and nonunion was observed in 1 patient. The clinical healing time was averaged 7.42 (range 5.0-16.0 months) months. There were no significant differences in the healing time and nonunion between the early stage and late stage groups (P > 0.05). In the early stage group, excellent functional recovery of affected limb was observed in 13 patients, good recovery in 11 patients, and fair recovery in 1 patient, and it was 17, 18 and 3 patients respectively in the late stage group. There was no significant difference in functional recovery of affected limbs between early stage and late stage groups (P > 0.05). These results showed that bone grafting within the induced membrane at different time has slight, but not significant effect on healing of bone defect. Other factors, such as the size and the integrity of induced membrane, the quality and quantity of bone graft material, and the stability of bone stumps had more significant effects on the healing of bone defects, in particular on the healing rate.

Objective To compare the effects of bone transport versus induced membrane technique for large segmental tibial defects.Methods The clinical data were analyzed retrospectively of 89 patients with large segmental tibial defect who had been treated at Department of Orthopaedics,Wuxi No.9 People's Hospital from June 2005 to February 2017 using bone transport or induced membrane technique.They were 58males and 31 females,aged from 13 to 74 years (average,38.0 years).The bone transport group had 59cases and the induced membrane technique group 30 cases.The 2 groups were compared in terms of preoperative general data and postoperative bone nonunion,bone healing time,complications and functional recovery of the adjacent joint.Results There were no statistically significant differences between the 2groups in terms of age,gender,cause or type of defects,associated injury,course of disease,functionary scores of the adjacent joint or number of operations,showing compatibility between the 2 groups (P ＞ 0.05).All the patients were followed up for 12 to 48 months (average,20 months).The bone transport group had significandy longer clinical healing time (14.7 ± 5.4 months) and significantly higher incidences of major complications (50.8％),minor complications (57.6％) and overall complications (83.1％) than the induced membrane technique group (11.2 ± 2.8 months,16.7％,26.7％ and 30.0％,respectively) (P ＜ O.05),but significantly lower functionary scores of the adjacent joint (86.4 ± 5.0 points) than the induced membrane technique group (88.8 ± 4.9 points) (P ＜ 0.05).Conclusions Both bone transport and induced membrane technique are effective repairs for large segmental tibial defects.However,induced membrane technique may be superior to bone transport in terms of bone healing,complications and functional recovery.

Objective: To investigate the effectiveness of meshy fascia encapsulating cancellous bone graft in repair of bone defect after limb fractures. Methods: A clinical data of 21 cases of traumatic bone defect after limb fractures, who were treated with meshy fascia encapsulating cancellous bone graft between June 2011 and December 2016, was retrospectively analyzed. There were 13 males and 8 females, aged 14-64 years with an average of 40.1 years. The location of bone defect included humerus in 3 cases, radius in 5 cases, ulna in 4 cases, femur in 2 cases, and tibia in 7 cases. AO classification of primary fractures were type A in 2 cases, type B in 7 cases, and type C in 12 cases. There were 14 cases of open fracture, and 7 cases of closed fracture associated with bone defect. The time from injury to bone defect repair was 5-165 days (mean, 21.3 days). The length of bone defect was 2.5-6.5 cm with an average of 4.5 cm. Results: The operation time was 86-130 minutes (mean, 101 minutes). The intraoperative blood loss was 185-647 mL (mean, 316 mL). One case of superficial infection and 2 cases of delayed healing of incision occurred after operation, and no neurovascular injury occurred. All the 21 patients were followed up 12-36 months (mean, 19 months). The clinical healing time was 2.5-7.0 months (mean, 5.4 months); no delayed healing and nonunion occurred, the bony healing rate was 100%. There was no deep infection, infection recurrence, broken of internal fixator, or refracture. At last follow-up, the grading of bony healing were all rated as excellent, and the functional recovery of the affected limb was excellent in 12 cases, good in 7 cases, and fair in 2 cases with an excellent and good rate of 90.5%. Conclusion: Meshy fascia encapsulating cancellous bone graft in repair of bone defect after limb fracture is characterized by easy to harvest fascia, simplicity of operation, no adverse reaction, lower cost, and satisfactory results.

Objective To investigate the augmentation plating for femoral fractures and postoperative femoral nonunion. Methods A retrospective analysis was conducted of 60 patients with femoral fracture or postoperative femoral nonunion who had been treated with augmentation plating from January 2008 to July 2015. They were 36 males and 24 females, aged from 15 to 79 years ( average, 43. 4 years ) . Of them, 20 cases suffered nonunion following intramedullary nailing of femoral shaft fracture, 18 nonunion following lateral plating for femoral distal or lower fracture, and 22 femoral distal or lower fracture complicated with comminuted fracture of medial column. An incision ranging from 6 to 10 cm was made around the fracture ends for augmentative plating for all the patients. Autogenous iliac bone graft was performed in patients with atrophic nonunion or ob-vious gap after reduction of the comminuted fracture. Operation time, intraoperative bleeding, healing time, complications, and functionary recovery of the affected knee were recorded. Results The operation time averaged 121. 5 min and the intraoperative bleeding 356. 3 mL. All the patients were followed up for 12 to 36 months ( average, 16. 9 months ) . All the fractures and nonunions healed after an average time of 4. 2 months ( from 3 to 4 months ) . The time for initial partial weight-bearing averaged 4. 5 weeks ( from 2 to 6 weeks ) and the time for initial full weight bearing 3. 3 months ( from 2 to 4 months ) . Evaluation according to the Karlstrom and Olerud criteria at the last follow-up revealed 29 excellent, 24 good and 7 fair cases, yielding an excellent and good rate of 88. 3％. No infection, loosening, bending or breaking of internal implants, or refracture was noted during follow-ups. Conclusion Augmentation plating through a small incision can lead to fine outcomes for femoral fractures and postoperative femoral nonunion, because it makes up the deficient stability of original in-ternal fixation, reduces the dislocated bone blocks and provides bone grafting to improve defective local bone structure and defective osteogenesis.

Objective To investigate the application value of transcranial Doppler ultrasonography(TCD) in critically ill children with cerebral dysfunction.Methods We detected the cerebral blood flow parameters[systolic velocity(Vs),mean velocity(Vm),end of diastolic velocity(Vd),pulsatility index(PI),resistance index(RI)] of middle cerebral artery in cerebral dysfunction group(n=20) and control group(no cerebral dysfunction,n=20),and observed the differences of those parameters between two groups.Children in cerebral dysfunction group were also divided into groups according to Glasgow Coma Score(GCS) and prognosis.The differences of each TCD parameter in diverse groups divided by GCS and by prognosis were analysed.Children in cerebral dysfunction group were checked TCD everyday until TCD parameters were normal.The relation between the days of TCD parameters′ reaching normal and GCS,duration of disorder of consciousness with correlation analysis were analysed.Results Vs,PI,RI in cerebral dysfunction group were higher than those in control group,while Vd was lower (P<0.05).(2)PI in the group of GCS less than 6 points(0.91±0.21) was higher than that in group of GCS 7-13 points(0.83±0.14)(P<0.05).The other parameters between two groups of GCS less than 6 points and GCS 7-13 points were not significantly indistinctive.Between the good prognosis group and the bad prognosis group,there were no significant differences in all parameters.(3) The days of TCD parameters′ reaching normal were negatively correlated with GCS(r=-0.653,P<0.01),but positively correlated with the duration of disorder of consciousness(r=0.923,P<0.01).Conclusion The cerebral hemodynamics of children with cerebral dysfunction is abnormal,the more serious cerebral dysfunction,the higher PI and the longer time for regaining normal TCD parameters.Constantly monitoring TCD could reflect the changes of cerebral hemodynamics and is valuable to assess the state of illness and prognosis.