Missing data represent a general problem in many scientific fields, especially in medical survival analysis. Dealing with censored data, interpolation method is one of important methods. However, most of the interpolation methods replace the censored data with the exact data, which will distort the real distribution of the censored data and reduce the probability of the real data falling into the interpolation data. In order to solve this problem, we in this paper propose a nonparametric method of estimating the survival function of right-censored and interval-censored data and compare its performance to SC (self-consistent) algorithm. Comparing to the average interpolation and the nearest neighbor interpolation method, the proposed method in this paper replaces the right-censored data with the interval-censored data, and greatly improves the probability of the real data falling into imputation interval. Then it bases on the empirical distribution theory to estimate the survival function of right-censored and interval-censored data. The results of numerical examples and a real breast cancer data set demonstrated that the proposed method had higher accuracy and better robustness for the different proportion of the censored data. This paper provides a good method to compare the clinical treatments performance with estimation of the survival data of the patients. This pro vides some help to the medical survival data analysis.
Algorithms ; Breast Neoplasms ; epidemiology ; Female ; Humans ; Probability ; Statistics, Nonparametric ; Survival Analysis

Objective To compare the efficacy and prognosis of epirubicin combined with paclitaxel and epirubicin combined with docetaxel in the treatment of breast cancer.Methods Patients in the study group were treated with epirubicin and paclitaxel, while the control group was treated with epirubicin plus docetaxel.Results The two groups of breast cancer patients by the end of the treatment were valid for 5 years of follow-up, five year survival rate(86.67%)than the control group(68.89%), the study group the recurrence rate(4.44%)than in the control group(15.56%), the data had significant differences(P<0.05).Conclusion The epirubicin is conducive to breast cancer patients for better disease control effect and prognosis than star, paclitaxel combined with chemotherapy.

BACKGROUND:The limitation of the traditional intramedulary nailing relies on the personal experience of the doctor. Moreover, the enlargement of the bone marrow causes the destruction of the biological environment of the marrow cavity and affects the healing of bone. OBJECTIVE:To observe therapeutic effect of digital technology assisted intramedulary nail fixation for femoral shaft fracture. METHODS:A total of 80 patients with femoral shaft fracture, who were treated in the Department of Orthopedics, Affiliated Hospital of Putian University from January 2010 to January 2014, were enroled. Digital technology was used to assist treatment. Three-dimensional digital model of femoral shaft fracture was established before treatment. Virtual reduction was conducted in the three-dimensional digital fractures. The diameter of medulary cavity was measured. Appropriate specification of intramedulary nailing was selected according to the measurement data. Closed reduction and intramedulary nailing were performed according to operation scheme of digital technology. RESULTS AND CONCLUSION:The 80 patients were folowed up for 12 to 24 months. Fractures were completely healed. At 12 months after treatment, they were evaluated by clinical curative effect standard in department of orthopedics. There were excelent in 62 cases, good in 15 cases, and good in 3 cases, with the excelent and good rate of 96%. No complications occurred such as infection, fixator breakage or loosening. These results verify that digital technology assisted intramedulary nail fixation for femoral shaft fracture obtained positive therapeutic effects, could obviously shorten operation time, reduce surgical trauma, and diminish intraoperative X-ray emission to patients and health care workers.

Objective To investigate the effect of Avastin (bevacizumab) combined with preoperative FOLFOX neoadjuvant chemotherapy on the prognosis of patients with locally advanced rectal cancer (LARC).MethodsA total of 80 cases of patients with LARC treated with total mesorectal excision (TME) in our hospital from January 2013 to January 2016 were randomly divided into the control group and the observation group, 40 cases in each group.The control group were treated with preoperative FOLFOX chemotherapy while the observation group were treated with bevacizumab injection, based on the treatment in the control group.21 days was a cycle of chemotherapy, and both groups were treated for at least 4 cycles.After 6 cycles of chemotherapy, operation was carried out, following TEM principle.The short-term and long-term prognosis, rate of R0 resection, the incidence of postoperative complications and side effects of chemotherapy were compared between the two groups.ResultsThere was no significant difference between the two groups in the good response rate of chemotherapy, the rate of R0 resection, the incidence of postoperative complications, the 1-year and 3-year survival rates and 1-year disease-free survival rate.The incidence rates of gastrointestinal reactions and bone marrow suppression in the observation group were 52.5% and 52.5%, respectively while in the control group were 25.0% and 20.0%, respectively (P<0.05), but there was no significant difference in the incidence rates of grade Ⅲ~Ⅳ gastrointestinal reaction and bone marrow suppression between the observation group and the control group (5.0% and 15.0% vs 2.5% and 5.0%).The 3-year disease-free survival rate of the observation group was higher than that of the control group (82.5% vs 60.0%) (P<0.05).ConclusionThe application of bevacizumab combined with preoperative FOLFOX chemotherapy in the treatment of LARC can improve the 3-year disease-free survival rate, without increasing postoperative adverse reactions and serious side effects of chemotherapy.

BACKGROUND:Odontoid fracture is very common in cervical spine injuries, the special position of odontoid process, which is adjacent to important anatomic structure, makes screw placement difficult, and a slight discrepancy in position and orientation of the inserted screw leads to a decrease in intensity of internal fixation, even invalid internal fixation. Therefore, it is very necessary to develop an individualized treatment protocol by which screws can be precisely and safely placed and which is worthy of clinical popularization. OBJECTIVE:To study the navigation of Mimics software and three dimensional (3D)-printed module in anterior odontoid cannulated screw fixation and to investigate its feasibility and accuracy. METHODS:Sixteen human cadaveric cervical spines were scanned by a continuous thin-slice CT scanner. Original DICOM CT images were three-dimensional y reconstructed using Mimics software. The screw channel and support column were designed for C2 vertebra odontoid cannulated screw fixation for odontoid fracture. Segmentation of bone surface was performed. Navigation modules with screw channel were built using 3D printing technique. Navigation modules were used to aid screw placement. Screw fitting and placement were evaluated using X-ray and CT scan. RESULTS AND CONCLUSION:Total y 16 navigation modules were built and 22 screws were implanted. During and after screw placement, the cortical bone along screw channel and surrounding the vertebral body was not cracked. Postoperative X-ray and CT scans showed that some factors regarding screw placement such as entry point, orientation and depth of placement were consistent with those ideal factors simulated by Mimics software. The navigation modules were closely attached to the corresponding bony structure in front of the vertebral body, with a satisfactory gomphosis. Screw fitting and stability were good during application. These results verify that with the aid of navigation module, anterior odontoid cannulated screw fixation is reliable for treatment of odontoid fracture, which provides insights into the popularization of 3D printing-based digital navigation technique in orthopedic implantation.

BACKGROUND:Preliminary experiments have performed three-dimensional (3D) reconstruction of proximal tibial fractures, digital steel plate design, the establishmentof the proximal tibia plate standard parts library and the operation simulation of 3D printing. OBJECTIVE:To explore feasibility and accuracy of standard parts library plates and screws in the proximal tibial fracture internal fixation navigation in digital design combined with 3D printing model on the basis of preliminary studies. METHODS:Dicom format images of continuous thin layer CT scanning were colected in 20 cases of proximal tibial fractures, and uploaded in Mimics software for 3D reconstruction and fracture reduction. Plate and screw selected from standard part library wereusedfor virtual fixation. Navigation module with screw channel was designed. 3D printing skeleton, bone plate, and navigation module were used for skeleton model and internal fixation. Screw and plate were placed by navigation. Navigation module card, nail and board position were observed. Postoperative appearance and CT scanning were utilized to assess outcomes. RESULTS AND CONCLUSION:After CT scanning and reconstructionin 20 skeleton models, in combination with appearance, the position of plate, screw insertion point, the direction, length and diameter of the screw were consistent with that in Mimics software. The navigation module and the corresponding proximal end of the tibia were closely bonded with good fitting degree. In the application, card slots and stability were good, and could perfectly guide plate and screw placement. These reuslts suggest that with the aid of navigation module, standard parts library plate internal fixation for proximal tibia fracture has high accuracy. On the basis of digital design and 3D printing, digital internal fixation technology of standard parts library plate is expected to achieve good implant navigation in the department of orthopedics.

BACKGROUND:On CT reconstruction of three-dimensional (3D) model, fracture virtual reduction and internal fixation cannot be achieved, and reasonable operation scheme cannot be formulated. Digital design can fuly meet the needs of clinical orthopedics physicians. Standard parts database can provide the possibility to choose the ideal internal fixation. 3D printing makes the reasonable operation scheme accurate in clinical implementation. OBJECTIVE:To discuss the feasibility, accuracy and minimal invasion of internal fixation in treatment of the distal femoral fracture with digital design of standard parts database by 3D printing. METHODS: (1) Nine adult lower extremity specimens were selected to take continuously thin-layer CT scanning. After Dicom images were imported into the mimics software, the model was established. According to the AO classification, they were classified into A1-3, B1-3 and C1-3 types of distal femoral fracture by virtual design. Internal fixation with plate and screw formed standard parts database virtualy. It was printed out the pilot hole of the navigation module design by three-dimensional printing forming technique. Plate and screw were inserted assisted by the module. X-ray and CT scan were taken postoperatively to access the position. (2) 30 patients with distal femoral fracture were subjected to above fixation. The operation time, intraoperative blood loss and postoperative drainage were recorded. Imaging and curative effects were evaluated during folow-up. RESULTS AND CONCLUSION: (1) Nine samples underwent X-ray and CT scan. 3D reconstruction results revealed plate position, screw entry point, nail direction, length and diameter were consistent with presetting data in Mimics software. The navigation models were designed to fit the lateral bony structure of distal femur. There were good fitting degree, good card position and good stability when the navigation was applied. It could guide plant and screw implantation. (2) In 30 cases, the operation time was (104.63±26.12) minutes, intraoperative blood loss was (121.74±11.49) mL, and postoperative drainage volume was (30.29±6.38) mL. Al patients were folowed up. According to Schagzker criterion, the efficiency of 22 cases was excelent, 6 cases good and 2 cases average, and the excelent and good rate was 93%. The parameters of length, diameter, orientation and angle were consistent with that preoperatively. (3) Internal fixation formed by standard parts database assisted by 3D printing navigation model has advantages of high accuracy, short process, lessened blood loss, high safety, less complications, and precise fixation. Digital design of standard parts database via3D printing navigation module is expected to achieve implant navigation and application.

Objective This study aimed to evaluate the safety and efficacy of video-assisted thoracoscopic bipolar radio-frequency ablation in the treatment of isolated paroxysmal atrial fibrillation.Methods From September 2010 to December 2016,Seventy-two consecutive patients with paroxysmal atrial fibrillation underwent video-assisted thoracoscopic bipolar radio-frequency ablation at Fuwai Hospital.There were 50 males and 22 females with an average age of(56.5 ± 10.5) years and duration of atrial fibrillation with (6.5 ± 4.8) years.45 patients had previous catheter ablation.The patients were followed up at postoperative 3 months,6 months,1 year and annually.Success of ablation was defined as sinus rhythm and no duration of ≥30 s for rapid atrial arrhythmias,including atrial fibrillation,atrial flutter or atrial tachycardia in 24 h Holter examination.Univariate and multivariate logistic regression models were used to analyze the risk factors for atrial fibrillation recurrence.Results One patient converted to sternotomy due to bleeding on operation.All patients were successfully discharged.69 patients completed follow-up,with an average follow-up of(28 ± 18)months(3-60 months).The overall success rate was 73.9％,and the success rate without antiarrhythmic drug was 62.3％.Subgroup analysis showed that the success rate was 80％ when left atrial anterior and posterior diameter(LAD) ≤40 mm,and 57.9％ when LAD ＞ 40 mm (P =0.035).Multivariate logistic regression analysis showed that LAD ＞40 mm was an independent risk factor for postoperative recurrence of atrial fibrillation.Conclusion Video-assisted thoracoscopic bipolar radiofrequency ablation is a safe and effective method for the treatment of paroxysmal atrial fibrillation,especially in patients with LAD≤40 mm.