Objective:To investigate the early clinical characteristics of elderly patients with severe burns and the risk factors on prognosis.Methods:This study was a retrospective case series study. Clinical data of 124 elderly patients with severe burns who met the inclusion criteria and were admitted to the 12 hospitals from January 2015 to December 2020 were collected, including 4 patients from the Fourth People's Hospital of Dalian, 5 patients from Fujian Medical University Union Hospital, 22 patients from Guangzhou Red Cross Hospital of Jinan University, 5 patients from Heilongjiang Provincial Hospital, 27 patients from the First Affiliated Hospital of Naval Medical University, 9 patients from the First Affiliated Hospital of Nanchang University, 10 patients from Affiliated Hospital of Nantong University, 9 patients from Tongren Hospital of Wuhan University & Wuhan Third Hospital, 12 patients from the 924 th Hospital of PLA, 6 patients from Zhangjiagang First People's Hospital, 4 patients from Taizhou Hospital of Zhejiang Province, and 11 patients from Zhengzhou First People's Hospital. The patients' overall clinical characteristics, such as gender, age, body mass index, total burn area, full-thickness burn area, inhalation injury, causative factors, whether combined with underlying medical diseases, and admission time after injury were recorded. According to the survival outcome within 28 days after injury, the patients were divided into survival group (89 cases) and death group (35 cases). The following data of patients were compared between the two groups, including the basic data and injuries (the same as the overall clinical characteristics ahead); the coagulation indexes within the first 24 hours of injury such as prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time, D-dimer, fibrinogen degradation product (FDP), international normalized ratio (INR), and fibrinogen; the blood routine indexes within the first 24 hours of injury such as white blood cell count, platelet count, neutrophil-to-lymphocyte ratio, monocyte count, red blood cell count, hemoglobin, and hematocrit; the organ function indexes within the first 24 hours of injury such as direct bilirubin, total bilirubin, urea, serum creatinine, aspartate aminotransferase, alanine aminotransferase, total protein, albumin, globulin, blood glucose, triglyceride, total cholesterol, alkaline phosphatase, creatine kinase, electrolyte indexes (potassium, sodium, chlorine, calcium, magnesium, and phosphorus in blood), uric acid, myoglobin, and brain natriuretic peptide; the infection and blood gas indexes within the first 24 hours of injury such as procalcitonin, C-reactive protein, pH value, oxygenation index, base excess, and lactate; treatment such as whether conducted with mechanical ventilation, whether conducted with continuous renal replacement therapy, whether conducted with anticoagulation therapy, whether applied with vasoactive drugs, and fluid resuscitation. The analysis was conducted to screen the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns. Results:Among 124 patients, there were 82 males and 42 females, aged 60-97 years, with body mass index of 23.44 (21.09, 25.95) kg/m 2, total burn area of 54.00% (42.00%, 75.00%) total body surface area (TBSA), and full-thickness burn area of 25.00% (10.00%, 40.00%) TBSA. The patients were mainly combined with moderate to severe inhalation injury and caused by flame burns. There were 43 cases with underlying medical diseases. The majority of patients were admitted to the hospital within 8 hours after injury. There were statistically significant differences between patients in the 2 groups in terms of age, total burn area, full-thickness burn area, and inhalation injury, and PT, APTT, D-dimer, FDP, INR, white blood cell count, platelet count, urea, serum creatinine, blood glucose, blood sodium, uric acid, myoglobin, and urine volume within the first 24 hours of injury (with Z values of 2.37, 5.49, 5.26, 5.97, 2.18, 1.95, 2.68, 2.68, 2.51, 2.82, 2.14, 3.40, 5.31, 3.41, 2.35, 3.81, 2.16, and -3.82, respectively, P<0.05); there were statistically significant differences between two groups of patients in whether conducted with mechanical ventilation and whether applied with vasoactive drugs (with χ2 values of 9.44 and 28.50, respectively, P<0.05). Age, total burn area, full-thickness burn area, serum creatinine within the first 24 hours of injury, and APTT within the first 24 hours of injury were the independent risk factors for the mortality within 28 days after injury in elderly patients with severe burns (with odds ratios of 1.17, 1.10, 1.10, 1.09, and 1.27, 95% confidence intervals of 1.03-1.40, 1.04-1.21, 1.05-1.19, 1.05-1.17, and 1.07-1.69, respectively, P<0.05). Conclusions:The elderly patients with severe burns had the injuries mainly from flame burns, often accompanied by moderate to severe inhalation injury and enhanced inflammatory response, elevated blood glucose levels, activated fibrinolysis, and impaired organ function in the early stage, which are associated with their prognosis. Age, total burn area, full-thickness burn area, and serum creatinine and APTT within the first 24 hours of injury are the independent risk factors for death within 28 days after injury in this population.

Objective:To compare the clinical efficacies of robot-assisted and free-hand long segment screw fixation combined with wedge osteotomy in the treatment of type IV chronic symptomatic osteoporotic thoracolumbar fractures (CSOVCFs).Methods:A retrospective cohort study was conducted to analyze the clinical data of 72 patients with type IV CSOVCFs who were admitted to Honghui Hospital of Xi′an Jiaotong University from May 2019 to December 2021, including 22 males and 46 females; aged 61-82 years [(71.2±12.3)years]. Fracture segments were located at T 11-T 12 in 37 patients and at L 1-L 2 in 31. A total of 32 patients were treated with robot-assisted long segment screw fixation combined with wedge osteotomy (robot group) and 36 with free-hand long segment screw fixation combined with wedge osteotomy (free-hand group). The operation time, intraoperative bleeding volume, dosage of radiation exposure, intraoperative needle adjustment, time of single pedicle screw placement and accuracy of pedicle screw placement were compared between the two groups. The kyphotic Cobb angle, sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar kyphosis (LL), visual analogue scale (VAS) and Oswestry disability index (ODI) were measured preoperatively, at 3 days postoperatively and at the last follow-up. The incidences of facet joint violation, deviation in guide needle placement, cerebrospinal leak and proximal junctional kyphosis (PJK) were observed. Results:All patients were followed up for 12-26 months [(18.2±5.1)months]. The operation time and time of single pedicle screw placement showed no significant differences between the two groups (all P>0.05). The intraoperative bleeding volume was (502.5±58.3)ml in the robot group, less than that in the free-hand group [(690.2±45.9)ml]. The dosage of radiation exposure was (32.6±10.8)μSv in the robot group, lower than that in the free-hand group [(48.6±15.2)μSv]. The intraoperative needle adjustment was (2.1±0.3)times in the robot group, higher than that in the free-hand group [(20.7±5.8)times], and the accuracy of pedicle screw placement was 99.7% in the robot group, less than that in the free-hand group (91.8%) (all P<0.01). Compared with pre-operation, the kyphotic Cobb angle, SVA, TK and LL were significantly improved in both groups at postoperative 3 days and at the last follow-up (all P<0.05). Compared with postoperative 3 days, the kyphotic Cobb angle, SVA and TK were increased at the last follow-up within the two groups, but with no significant differences (all P>0.05). Compared with postoperative 3 days, the LL was decreased within the two groups at the last follow-up, but with no significant differences (all P>0.05). The VAS and ODI in the two groups were significantly lower at postoperative 3 days and at the last follow-up when compared with those before operation (all P<0.05), and both values were significantly lower at the last follow-up than those at postoperative 3 days (all P<0.05). There were no significant differences in the VAS or ODI at all time points between the two groups (all P>0.05). The incidence of facet joint violation in the robot group was 1.6%, markedly lower than that in the free-hand group (9.6%) ( P<0.01). The incidences of deviation in guide needle placement, cerebrospinal leak and PJK showed no differences between the two groups (all P>0.05). Conclusion:For type IV CSOVCFs, the robot-assisted long segment screw fixation combined with wedge osteotomy can better reduce intraoperative blood loss, decrease radiation exposure, improve accuracy of pedicle screw placement, and reduce facet joint violation when compared with free-hand long segment screw fixation combined with wedge osteotomy.

Objective:To compare the clinical efficacies of O-arm combined with CT three-dimensional navigation system assisted screw placement versus manual screw placement in treating lower cervical fracture and dislocation.Methods:A retrospective cohort study was used to analyze the clinical data of 41 patients with lower cervical fracture and dislocation, who were treated in Honghui Hospital, Xi′an Jiaotong University from May 2021 to February 2022. The patients included 26 males and 15 females, aged 31.5-48.6 years [(41.5±15.0)years]. The injured segments were C 3 in 3 patients, C 4 in 12, C 5 in 13, C 6 in 10 and C 7 in 3. Nineteen patients were treated with cervical pedicle screws by O-shaped arm combined with CT three-dimensional navigation system (navigation group, 76 screws) and 22 by bare hands (traditional group, 88 screws). The total operation time, effective operation time, single nail placement time, single screw correction times, screw distance from anterior cortex, intraoperative blood loss, intraoperative fluoroscopic radiation dose, incision length and length of hospital stay were compared between the two groups, and the height of intervertebral space, Cobb angle, interbody slip distance and American Spinal injury Association (ASIA) grade were compared before operation and at 3 days after operation. Visual analogue score (VAS), Japanese Orthopedic Association (JOA) score, and neck dysfunction index (NDI) were evaluated before operation, at 3 days, 3 months after operation and at the last follow-up. Accuracy of screw placement and incidence of complications (adjacent facet joint invasion, infection, screw loosening) were detected as well. Results:All the patients were followed up for 11.1-13.9 months [(12.5±1.4)months]. The total operation time, intraoperative blood loss, intraoperative fluoroscopic radiation dose and incision length in the navigation group were more or longer than those in the traditional group (all P<0.05). The effective operation time, single nail placement time, single nail correction times and screw distance from anterior cortex in the navigation group were markedly less or smaller than those in the traditional group (all P<0.05). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). There were significant improvements in the height of intervertebral space, Cobb angle and interbody slip distance between the two groups at 3 days after operation (all P<0.05). There was no significant difference in the height of intervertebral space, Cobb angle, interbody slip distance or ASIA grade between the two groups before operation or at 3 days after operation (all P>0.05). Compared with pre-operation, the VAS, JOA score and NDI were significantly improved in both groups at 3 days, 3 months after operation and at the last follow-up (all P<0.05), with further improvement with time. There was no significant difference in VAS between the two groups before operation or at 3 months after operation (all P>0.05), but it was markedly lower in the navigation group compared with the traditional group at 3 days after operation and at the last follow-up (all P<0.05). There were no significant differences in JOA score or NDI between the two groups before operation or at 3 days and 3 months after operation (all P>0.05), but both were lower in the navigation group compared with the traditional group at the last follow-up (all P<0.05). The accuracies of placement of grade 0 and grade 0+1 screws were 92.0% (70/76) and 96.6% (73/76) in the navigation group, respectively, which were markedly higher than 88.7% (78/88) and 93.5% (82/88) in the traditional group (all P<0.05). The rates of adjacent facet joint invasion of A, B, and C degrees were 71.2% (54/76), 28.8% (22/76) and 0% (0/76) in the navigation group, respectively, while the invasion rates were 60.5% (53/88), 32.3% (28/88) and 7.3% (7/88) in the traditional group ( P<0.05). No screw loosening was noted in the navigation group, but the screw loosening rate was 9.1% (8/88) in the traditional group ( P<0.01). Conclusion:Compared with manual screw placement, O-arm combined with CT three-dimensional navigation system assisted screw placement for lower cervical fracture and dislocation has the advantages of shorter effective operation time, quicker screw placement, stronger screw holding force, better cervical stability, slighter postoperative pain, higher screw placement accuracy, and lower facet joint invasion and screw loosening rates.

OBJECTIVE To investigate the improvement mechanism of caudatin on liver injury of rats. METHODS SD rats were randomly divided into blank group， model group， caudatin low-dose and high-dose groups （25， 50 mg/kg）， with 6 rats in each group. Diethylnitrosamine （DEN） was injected intraperitoneally three times per week for eight weeks to establish liver injury model of rats. At 5th week of modeling， the rats received relevant medicine or 0.5% sodium carboxymethylcellulose intragastrically for 4 weeks. The levels of liver function indexes [alanine transaminase （ALT）， aspartate transaminase （AST）， total protein （TP） and total bilirubin （TBI）] and inflammatory factors [interleukin （IL-6）， tumor necrosis factor α （TNF-α）， IL-1β] in serum were detected； the histopathological morphological changes of rat liver were observed； the positive protein expressions of nuclear factor κB （NF-κB） and 78 kDa glucose regulatory protein （Grp78） in liver tissue were also determined； the expressions of endoplasmic reticulum stress-related protein Grp78， C/EBP homologous protein （CHOP）， activating transcription factor 6 （ATF6） and inositol requiring enzyme 1α （IRE1α） and the level of protein kinase R-like endoplasmic reticulum kinase robertluoyi@126.com （PERK） in liver tissue were detected. RESULTS Compared with blank group， serum levels of ALT， AST， TBI， IL-6， TNF-α and IL-1β and positive expressions of NF-κB and Grp78 in liver tissue as well as protein expressions of Grp78， CHOP， ATF6 and IRE1α， PERK protein phosphorylation level were all increased significantly in model group （P＜0.05）， while the serum level of TP was decreased significantly （P＜0.05）. The disordered structure of liver lobule， swollen liver cells， unclear intercellular boundary were observed and accompanied by inflammatory cell infiltration. Compared with model group， most of the above indexes were significantly reversed in caudatin groups （P＜0.05）； the structure of hepatic lobule was relatively complete and clear， the cells were arranged orderly， and the infiltration of inflammatory cells was also reduced. CONCLUSIONS Caudatin has a significant improvement effect against DEN-induced liver injury in rats， the mechanism of which may be associated with inhibiting endoplasmic reticulum stress and inflammatory reaction.

Objective:To compare the efficacy of cervical decompression performed at different times in the treatment of incomplete cervical spinal cord injury.Methods:A multicenter retrospective cohort study was conducted to analyze the clinical data of 96 patients with incomplete cervical spinal cord injury admitted to six hospitals including Honghui Hospital affiliated to Xi'an Jiaotong University, etc, from May 2018 to May 2021. There were 36 females and 60 males, aged 28-42 years [(35.2±6.7)years]. The injured segments were at C 3 in 7 patients, C 4 in 15, C 5 in 20, C 6 in 23 and C 7 in 31. According to the American Spinal Injury Association (ASIA) scale, there were 59 patients with grade B, 27 grade C, and 10 grade D. A total of 36 patients underwent cervical decompression within 24 hours after injury (early group), 33 patients within 24-72 hours after injury (late group), and 27 patients within 4-14 days after injury (delayed group). The operation time, intraoperative blood loss, postoperative drainage, length of hospital stay, Cobb angle, height of intervertebral space and space occupation of the spinal canal before surgery and at postoperative 3 days, and ASIA score, ASIA motor score, ASIA light tactile score, ASIA acupuncture sensation score, visual analog scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck dysfunction index (NDI) before surgery and at postoperative 3 months, 1 year and at the last follow-up and incidence of complications were compared among the three groups. Results:All the patients were followed up for 12-21 months [(16.4±4.2)months]. There was no significant difference in the operation time among the three groups (all P>0.05). The intraoperative blood loss and postoperative drainage volume in the early group were (312.5±5.2)ml and (165.3±45.8)ml, which were higher than those in the late group [(253.5±40.0)ml, (120.4±60.6)ml] and the delayed group [(267.3±36.8)ml and (130.4±38.6)ml] (all P<0.01). There was no significant difference between the late group and the delayed group (all P>0.05). The length of hospital stay in the early group was (5.2±1.6)days, which was shorter than that in the late group [(7.6±2.3)days] and the delayed group [(8.0±1.3)days] (all P<0.05), but there was no significant difference between the late group and the delayed group ( P>0.05). There was no significant difference in the Cobb angle, height of intervertebral space and space occupation of the spinal canal among the three groups before and at postoperative 3 days (all P>0.05). There was no significant difference in the ASIA score, ASIA motor score, ASIA light tactile score, ASIA acupuncture sensation score, VAS score, JOA score and NDI among the three groups before surgery (all P>0.05). At postoperative 3 months, 1 year and at the last follow-up, the ASIA grading of the early group was better than that of the late group and the delayed group ( P<0.05 or 0.01), but there was no statistically significant difference between the late group and the delayed group (all P>0.05). The ASIA motor scores of the early group were (56.4±4.5)points, (76.3±3.6)points and (85.4±6.5)points at postoperative 3 months, postoperative 1 year and the last follow-up, respectively, which were higher than those in the late group [(52.3±2.4)points, (60.3±8.6)points and (72.3±2.4)points] and the delayed group [(51.9±2.3)points, (62.8±4.6)points and (71.9±1.3)points]; the ASIA light tactile scores of the early group were (70.2±2.9)points, (72.6±4.3)points and (78.3±2.3)points, which were higher than those in the late group [(66.2±3.7)points, (68.3±1.6)points and (73.3±1.6)points] and the delayed group [(65.2±2.1)points, (67.8±1.9)points and (72.3±2.5)points]; acupuncture sensation scores of the early group were (71.9±3.1)points, (80.1±3.8)points and (89.1±7.6)points, which were higher than those in the late group [(67.4±2.7)points, (72.6±3.7)points and (77.9±1.8)points] and the delayed group [(68.3±2.2)points, (72.6±3.1)points and (77.2±1.9)points] (all P<0.05). VAS scores of the early group at postoperative 3 months, 1 year and at the last follow-up were (4.3±0.6)points, (2.4±0.3)points and (1.6±0.2)points, which were lower than those in the late group [(5.1±1.3)points, (4.1±0.6)points and (3.0±0.6)points] and the delayed group [(5.0±1.7)points, (4.0±0.8)points and (3.1±0.2)points]; JOA scores of the early group were (12.8±1.6)points, (14.4±2.6)points and (17.9±3.3)points, which were higher than those in the late group [(11.9±1.9)points, (13.3±1.6)points and (8.9±1.3)points] and the delayed group [(11.6±1.8)points, (13.2±1.4)points and (9.3±2.1)points]; NDI scores of the early group were 12.1±3.3, 10.1±2.1 and 7.3±1.4, which were lower than those in the late group (14.4±3.1, 12.3±1.6 and 8.9±1.3) and the delayed group (14.1±2.3, 12.9±1.9 and 9.5±2.1) (all P<0.05). There was no significant difference in all the above-mentioned scores at postoperative 3 months, 1 year and at the last follow-up between the late group and the delayed group (all P>0.05). The incidence of complications was 25.0% (9/36) in the early group, 27.3% (9/33) in the late group and 37.0% (10/27) in the delayed group (all P>0.05). Conclusion:Compared with within 24-72 hours and 4-14 days after injury, cervical decompression performed within 24 hours after injury for patients with incomplete cervical spinal cord injury can shorten the length of hospital stay, improve the function of the spinal cord nerves and relieve pain, with no increase of the incidence of complications.

Objective:To study the inactivation effects of microwave on human adenovirus 2 (HAdV-2) in simulated infectied wastes, and to explore its molecular mechanism.Methods:25 μl of HAdV-2 virus suspension was dripped with medical disposable gloves, masks and cotton swabs to simulate infectied wastes, and irradiated under different microwave conditions: gloves and masks were irradiated for 30 s, 60 s, and 90 s at 300 W, 500 W, and 700 W, respectively. Cotton swabs irradiate 60 s, 90 s, 120 s at 500 W and 700 W respectively. Temperature changes were recorded, and the inactivation logarithmic values were calculated by the 50% endpoint method to evaluate the microwave inactivation effects, and the proliferation ability of the virus was detected by qPCR. The damage of Penton, Fiber, Hexon and E2 B genes was detected by PCR. The virus was treated with the highest temperature of 76 ℃ during microwave irradiation to study whether there was non-thermal effect during microwave disinfection. Results:After microwave irradiation of infectied waste, the temperature of masks and gloves carriers rises rapidly, with the highest temperature of 76 ℃. The temperature of the cotton swab carriers rose slowly, and the highest temperature is 65 ℃. The inactivation effect of microwave on HAdV-2 was positively correlated with microwave power and irradiation time. In the mask and glove group, microwave power of 700 W irradiated for 60 seconds, and the inactivation logarithm value could reach 3.0, In the cotton swab group, microwave power of 700 W irradiated for 120 seconds, and the inactivation logarithm value was still less than 3.0. This indicated that there were differences in the conditions for microwave inactivation of the virus in different carriers. The qPCR result showed that microwave irradiation could weak the proliferation ability of the virus. Microwave irradiation had no effect on the virus's Penton and Fiber genes, but caused some damage to the Hexon and E2 B genes. The inactivation effect of individual heat treatment on HAdV-2 was weaker than that of microwave irradiation, and there was no damage to the Hexon, Penton, Fiber, and E2 B genes. This indicated the presence of non thermal effects during the microwave inactivation process. Conclusions:Microwave irradiation can inactivate HAdV-2 in simulated infectied wastes through thermal and non-thermal effects, and its damage to viral DNA is one of the mechanisms of virus inactivation.

【Objective】 To explore the clinical effect of unilateral double-channel endoscope-assisted bone graft fusion and internal fixation (ULIF) in the treatment of recurrent lumbar disc herniation. 【Methods】 The clinical data of 22 patients with recurrent lumbar disc herniation treated by ULIF in our hospital from August 2020 to October 2020 were analyzed retrospectively. The study indicators included intraoperative blood loss, operation time, bed rest time, and hospital stay. The follow-up data included visual analogue score (VAS) of low back pain, Japanese Orthopaedic Association score (JOA), OSwestry disability index (ODI) score, as well as 36 concise health status survey (SF-36) scores before operation, and 1 week and 6 months after operation. 【Results】 The average operation time was (179.15±42.06) minutes, the average intraoperative blood loss was (132.67±41.92) mL, the average bed rest time was (1.51±0.42) days, and the average hospital stay was (4.82±1.13) days. The VAS score of low back pain at 1 week after operation was lower than that before operation (all P<0.000 1), and further decreased during the follow-up. The ODI score, JOA score and SF-36 score of postoperative follow-up were significantly different from those before operation (P<0.05). The satisfaction rate was 86.4% at 1 week after operation and 95.4% at 6 months after operation. The proportion of significant clinical efficacy at 1 week after operation and postoperative 6 months was 18.2% and 63.6%, respectively. 【Conclusion】 ULIF has the advantages of short-term recovery, less intraoperative blood loss, short bed rest and hospital stay, and good medium-term clinical effect. It is a safe and reliable minimally invasive technique for spinal surgeons in the treatment of recurrent lumbar disc herniation.

Objective:To study the differences in the cumulative dose between deformable image registration (DIR) and simple dose-volume histogram (DVH) summation in the fractionated brachytherapy of cervical cancer, and to analyze the feasibility of the application of DIR in the dosimetry assessment of targets and organs-at-risk (OARs) in the brachytherapy.Methods:A retrospective analysis was conducted for 13 cases with primary cervical cancer treated with four fractions of interstitial brachytherapy guided by CT images. The four CT images of each cases were registered using an intensity-based DIR. Then, the cumulative doses (the D2 cm 3, D1 cm 3, and D0.1 cm 3 of the bladder, rectum, intestine, and colon and the D90for targets) after DIR were calculated and compared to those obtained using simple DVH summation. Afterward, the correlation between the dose difference and dice similarity coefficient (DSC) was analyzed. With the dose difference (the remaining dose of OARs caused by the DIR) as limits, a new plan was made for the latest CT to calculate the dose increase to targets. Results:Compared to simple DVH summation, DIR allowed the cumulative doses of the D2 cm 3 and D1 cm 3 of bladder to be decreased by (2.47±1.92) and (2.82±2.73) Gy, respectively on average ( t=-3.65, -2.93, P < 0.05), those of the D2 cm 3, D1 cm 3, and D0.1 cm 3 of rectum to be decreased by (2.05 ± 1.61) Gy, (1.51 ± 1.58), and (3.21 ± 2.50) Gy, respectively on average ( t=-4.02, -3.02, -4.06, P < 0.05), and those of the D2 cm 3, D1 cm 3, and D0.1 cm 3 to be decreased by (1.42 ± 0.99), (1.55 ± 1.28) Gy, and (2.43 ± 1.95) Gy, respectively on average ( t=-3.52, -2.96, -3.06, P < 0.05). There was no significant statistical difference in the D90 of targets, the D0.1 cm 3 of the bladder, and the D2 cm 3, D1 cm 3, D0.1 cm 3 of the colon ( P > 0.05) between both methods, and there was no distinct correlation between DSC and dose difference ( P > 0.05). The DIR increased the dose to targets, with a median value of 150 cGy. However, the accuracy of the DIR should be improved. Conclusions:In clinical practice of multiple fractions of brachytherapy for cervical cancer, it′s still recommended to adopt the simple dose summation method to assess the doses to targets and OARs.

Objective:To compare the clinical efficacy between puncture assisted by a "TINAVI" orthopaedic robot versus freehand puncture in vertebroplaty for osteoporotic vertebral compression fracture(OVCF) of the upper thoracic vertebra.Methods:A retrospective study was conducted of the 19 patients (20 vertebral bodies) with OVCF of the upper thoracic vertebra who had been treated at Department of Spine Surgery, Honghui Hospital from January 2018 to March 2019 by robotic vertebroplasty (robot group) and of another 21 counterpart patients (21 vertebral bodies) who had been treated by conventional vertebroplasty from January 2016 to December 2017 (freehand group). Puncture was conducted by a "TINAVI" orthopaedic robot in the robotic vertebroplasty but freehand in the conventional vertebroplasty. The robot group had 5 males and 14 females, aged from 62 to 88 years; the freehand group had 6 males and 15 females, aged from 64 to 83 years. The 2 groups were compared in terms of operation time, bone cement volume, postoperative complications (cement leakage, infection and embolism), visual analogue scale (VAS), Oswestry disability index (ODI), anterior height (AH) and kyphosis angulation (KA) of the injured vertebra at day 1 and last follow-up after surgery.Results:The 2 groups were comparable because there were no significant differences between them in the preoperative general data ( P>0.05). Vertebroplasty via unilateral puncture approach was completed uneventfully in the 19 patients (20 vertebral bodies) in the robot group and in the 21 patients (21 vertebral bodies) in the freehand group. The 40 patients were followed up for 6 to 12 months (mean, 8.3 month). The operation time [(37.9±8.2) min], bone cement volume [(2.3±0.9) mL] and rate of cement leakage (10.0%, 2/20) in the robot group were all significantly less or lower than those in the freehand group [(46.2±9.4) min, (4.2±1.3) mL and 42.9% (9/21)] ( P<0.05). No infection or embolism was observed in either group. There were no significant differences between the 2 groups in VAS, ODI, AH or KA of the injured vertebra at day 1 or last follow-up after surgery ( P>0.05). Conclusion:In vertebroplaty for OVCF of the upper thoracic vertebra, compared with conventional freehand puncture, puncture assisted by a "TINAVI" orthopaedic robot can lead to satisfactory clinical efficacy because it reduces operation time, volume of bone cement injection, and thus incidence of bone cement leakage.

Objective:To establish a dosimetric method based on the well-chamber to verify the accuracy of the source positioning and dwelling time for the afterloading machine, aiming to provide a new method for the quality control of afterloading machine.Methods:The principle of this method was explained according to the hardware structure of the well-chamber. Then, the precision of this method was analyzed by the simulation test and data fitting. The feasibility test was also performed. And the advantages and disadvantages of this method were compared with those of the traditional method.Results:The precision of this method for detecting the source positioning was 0.07 mm and the dwelling time was 0.09 s, respectively. In the feasibility test, the standard deviation of the measure value was below 3%.Conclusions:The well-chamber method has high precision and convenient operation. It can be applied in the rapid verification of the relative accuracy of the source positioning and dwelling time of well-chamber.