In this study, we present deep learning‐based approaches to automatic segmentation and applicator reconstruction with high accuracy and efficiency in the planning computed tomography (CT) for cervical cancer brachytherapy (BT). A novel three‐dimensional (3D) convolutional neural network (CNN) architecture was proposed and referred to as DSD‐UNET. The dataset of 91 patients received CT‐based BT of cervical cancer was used to train and test DSD‐UNET model for auto‐segmentation of high‐risk clinical target volume (HR‐CTV) and organs at risk (OARs). Automatic applicator reconstruction was achieved with DSD‐UNET‐based segmentation of applicator components followed by 3D skeletonization and polynomial curve fitting. Digitization of the channel paths for tandem and ovoid applicator in the planning CT was evaluated utilizing the data from 32 patients. Dice similarity coefficient (DSC), Jaccard Index (JI), and Hausdorff distance (HD) were used to quantitatively evaluate the accuracy. The segmentation performance of DSD‐UNET was compared with that of 3D U‐Net. Results showed that DSD‐UNET method outperformed 3D U‐Net on segmentations of all the structures. The mean DSC values of DSD‐UNET method were 86.9%, 82.9%, and 82.1% for bladder, HR‐CTV, and rectum, respectively. For the performance of automatic applicator reconstruction, outstanding segmentation accuracy was first achieved for the intrauterine and ovoid tubes (average DSC value of 92.1%, average HD value of 2.3 mm). Finally, HDs between the channel paths determined automatically and manually were 0.88 ± 0.12 mm, 0.95 ± 0.16 mm, and 0.96 ± 0.15 mm for the intrauterine, left ovoid, and right ovoid tubes, respectively. The proposed DSD‐UNET method outperformed the 3D U‐Net and could segment HR‐CTV, bladder, and rectum with relatively good accuracy. Accurate digitization of the channel paths could be achieved with the DSD‐UNET‐based method. The proposed approaches could be useful to improve the efficiency and consistency of treatment planning for cervical cancer BT.
Background: Recent studies have found that microRNAs (miRNAs) play a critical role in development and progression of intervertebral disc degeneration. In the present study, we examined the role of miR-185 in nucleus pulposus cell behavior in vitro and the histological changes of intervertebral disc tissue in intervertebral disc degeneration rat models in vivo. Methods: Intervertebral disc degeneration models were developed in Sprague-Dawley rats. Intervertebral disc tissue was collected for histological evaluation after miR-185 agomir/agomir transduction. Next, nucleus pulposus tissues were collected from lumbar intervertebral discs to isolate nucleus pulposus cells, which were treated with miR-185 mimic/inhibitor and an inhibitor of the Wnt signaling pathway to assess cell viability and apoptosis. Results: We observed a high expression of Galectin-3 in nucleus pulposus cells of rats with intervertebral disc degeneration. Bioinformatics prediction and dual-luciferase reporter assay confirmed that miR-185 specifically binds to and negatively regulates Galectin-3. Furthermore, we found that miR-185 inhibition resulted in increased expression of Galectin-3, pro-autophagy factors (LC3 and Beclin-1), and pro-apoptosis factors (caspase-3 and Bax), along with the activation of the Wnt/b-catenin signaling pathway. Moreover, the gain-and loss-of-function studies suggested that miR-185 overexpression promoted cell viability and inhibited nucleus pulposus cell apoptosis and autophagy via inactivation of the Wnt/b-catenin signaling pathway. Moreover, miR-185 agomir alleviated the histological changes observed in intervertebral disc tissues in intervertebral disc degeneration rats, which helped us validate the results observed in vitro. Conclusions: Overexpression of miR-185 promotes nucleus pulposus cell viability and reduces the histological changes observed in intervertebral disc tissues in rats with intervertebral disc degeneration via inactivation of the Wnt/b-catenin signaling pathway and Galectin-3 inhibition. Our findings also highlight the potential of miR-185 as a promising novel therapeutic target to prevent and control intervertebral disc degeneration.
Objective To assess and compare the clinical outcomes and complications of TightRope® fixation vs hook plate fixation for the treatment of Rockwood III‐VI Acromioclavicular joint (ACJ) dislocations. Methods Relevant studies were identified by searching PubMed, Embase, and Web of Science databases, from their inception to 12 April, 2019. The main outcomes of interest included Constant Score, University of California Los Angeles (UCLA) Shoulder Score, Visual Analogue Scale (VAS), coracoclavicular distance (CCD), and complications. Weight mean difference (WMD) with 95% confidence intervals (95% CIs) or risk ratio (RR) with 95% CIs was used to calculate the data. Results Four studies with a total of 179 patients were included in this study. Compared with hook plate, TightRope® fixation was associated with a significantly less VAS score for pain (WMD = ‐0.69, 95% CI: −1.10, −0.27; P = 0.001). However, there were no significant differences between the two surgical techniques in terms of Constant Score (WMD = 6.12, 95% CI: −3.84, 16.08; P = 0.229), UCLA (WMD = 7.96, 95% CI: −5.76, 21.68; P = 0.256), CCD (WMD = 0.24, 95% CI: −0.67, 1.15; P = 0.602), and complication rate. Conclusion Both TightRope® and hook plate techniques offered effective outcomes in relieving the pain of dislocation and improving function of ACJ. However, TightRope® fixation showed an advantage over hook plate in terms of postoperative pain. Further larger‐scale RCTs are needed to verify our findings.
In the last few years, Concurrent Engineering (CE) has become a very prevalent topic in the area of manufacturing engineering. It has been viewed as one of the most effective, potential, and miraculous cures for maintaining the winning position of the American manufacturing industry in global competition. However, because CE is such a comprehensive topic which covers a wide spectrum of areas of study, there is a need to clarify the up-to-date research activities and industrial applications in the manufacturing engineering area. This paper first discusses the history and essence of CE, and then overviews seven areas of CE study in the manufacturing engineering perspective, as well as several industrial applications of CE. Because the studies on CE are still evolving, this paper aims to stimulate further explorations by providing a thorough survey on both theoretical and application research efforts in the past decade.
Background This retrospective study sought to delineate the radiographic characteristics of DDH patients over 13 years of age and investigate whether the lateral center-edge angle (LCEA) could serve as radiographic selection criteria for periacetabular osteotomy. Methods We enrolled patients with Hartofilakidis type I DDH without dislocation who underwent periacetabular osteotomy between August 2009 and August 2012. LCEA, anterior central edge angle (ACEA), femoral neck-shaft angle (FNSA), Shenton line and Tönnis acetabular index (AI) were evaluated by anteroposterior and 65° false⁃profile pelvic X-ray radiographs in the standing position. Femoral neck anteversion angle (FNA), labral lesion, labral inversion and cartilage lesion were evaluated by direct magnetic resonance arthrography. DDH was categorized by LCEA into four grades (grade I: 10° ≤ LCEA< 20°, grade II: 0° ≤ LCEA< 10°, grade III: -10° ≤ LCEA< 0°, grade IV: LCEA<-10) and osteoarthritis (OA) severity was assessed using Tönnis OA classification. Pearson correlation analysis was done between LCEA and other variables. Results Totally patients (274 hips) with a mean age of 27.3 years (range 13–47 years) were included. The mean LCEA was 3.5° (range: − 30° to 20°). Based on LCEA grades, grade I DDH was present in 104 hips, grade II in 40 hips, grade III in 76 hips, and grade IV in 54 hips. Based on Tönnis OA classification, 54.5% hips (150/274) were grade 0, 33.1% hips (91/274) grade 1, 8.4% hips (23/274) grade 2 and 4% hips (11/274) grade 3. Pearson correlation analysis showed a negative correlation between LCEA grade and Tönnis OA grades ( r = 0.3987; P < 0.001). Cochran-Armitage trend test further showed a positive correlation between LCEA grades and labral lesion ( P < 0.001) and interrupted Shenton line ( P < 0.001). Conclusion The LCEA classification scheme offers a simple and practical approach to categorize the level of acetabulum coverage on the femoral head, hip deformity and characteristics of DDH. Our findings could provide clinically useful guidance for orthopedic surgeons in preparation for periacetabular osteotomy in DDH patients aged above 13 years.
Background We investigated and characterized the performance of a novel orthogonal dual-layer multileaf collimator (αMLC) mounted on the LinaTech VenusX medical linear accelerator. Methods We evaluated leaf positioning accuracy and reproducibility using electronic portal imaging device (EPID) images of the picket fence test. The average, interleaf, and leaf-end transmissions of the upper, lower, and both αMLC layers were measured using an ionization chamber or EPID. The square and rhombus fields were used to evaluate the leaf penumbra of αMLC. To investigate the advantages of an orthogonal dual-layer MLC in field shaping, a right triangular pattern field, and a circular pattern field were formed using both layers and a single layer of the αMLC. These two evaluation pattern fields imaged were acquired by EPID and compared. Results The deviations in the positioning accuracy of the upper and lower MLC were 0.76 mm and 0.62 mm, respectively. Reproducibility was 0.29 mm and 0.26 mm correspondingly. The measured average transmissions were 1.86%, 1.82% and 0.03% for upper-, lower- and dual-layer MLC, respectively. The maximum interleaf transmission of the lower-layer MLC was 2.22% and 0.21% for the dual-layer. The maximum leaf-end transmissions were 23.90% and 0.44% correspondingly. Penumbra of the square field is 6.2 mm in X direction and 8.0 mm in Y direction. Average penumbras of the rhombus fields with side lengths of 5 cm and 10 cm were 3.6 mm and 4.9 mm, respectively. For the right triangular and circular fields, the fields shaped by the dual-layer of the αMLC were much closer to the planned field than the single-layer MLC. The dose undulation amplitude of the 50% isodose lines and the leaf stepping angle change of both layers was smaller than the single-layer MLC. Conclusions The αMLC benefits from its orthogonal dual-layer design. Leaf transmission, dose undulations at the field edge, and MLC field dependence of the leaf stepping angle of the dual-layer αMLC were remarkably reduced. αMLC can potentially improve the quality of IMRT and VMAT plans.
Background Breast cancer is one of the most common cancer diagnosed among US women. Early and accurate diagnosis using breast biopsy techniques is essential in detecting cancer. Methods In this paper, we present a new cable‐driven robot for MRI‐guided breast biopsy. A compact three degree‐of‐freedom (DOF) semi‐automated robot driven by ultrasonic motors is designed with non‐magnetic materials. Next, a novel insertion trajectory planning algorithm based on the breast holder that we created is proposed and designed, which can help radiologists locate the lesion and calculate the insertion trajectory. To improve the accuracy of insertion, kinematic analysis and accuracy compensation methods are introduced. Results An experimental study based on image recognition and positioning is performed to validate the performance of the new robot. The results show that the mean position accuracy is 0.7 ± 0.04 mm. Conclusions Application of the new robot can improve breast biopsy accuracy and reduce surgery time.
Nowadays, biopsy is a decisive method of lung cancer diagnosis, whereas lung biopsy is time-consuming, complex and inaccurate. So a computed tomography-compatible robot for rapid and precise lung biopsy is developed in this article. According to the actual operation process, the robot is divided into two modules: 4-degree-of-freedom position module for location of puncture point is appropriate for patient's almost all positions and 3-degree-of-freedom tendon-based orientation module with remote center of motion is compact and computed tomography-compatible to orientate and insert needle automatically inside computed tomography bore. The workspace of the robot surrounds patient's thorax, and the needle tip forms a cone under patient's skin. A new error model of the robot based on screw theory is proposed in view of structure error and actuation error, which are regarded as screw motions. Simulation is carried out to verify the precision of the error model contrasted with compensation via inverse kinematics. The results of insertion experiment on specific phantom prove the feasibility of the robot with mean error of 1.373 mm in laboratory environment, which is accurate enough to replace manual operation.
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