Background
Leveraging the precision of its radiation dose distribution and the minimization of postoperative complications, low‐dose‐rate (LDR) permanent seed brachytherapy is progressively adopted ...in addressing hepatic malignancies.
Purpose
The present study endeavors to devise a sophisticated treatment planning system (TPS) to optimize LDR brachytherapy for hepatic lesions.
Methods
Our TPS encompasses four integral modules: multi‐organ segmentation, seed distribution initialization, puncture pathway selection, and inverse dose planning. By amalgamating an array of deep learning models, the segmentation module proficiently labels 17 discrete abdominal targets within the images. We introduce a knowledge‐based seed distribution initialization methodology that discerns the most analogous tumor shape in the reference treatment plan from the knowledge base. Subsequently, the seed distribution from the reference plan is transmuted to the current case, thus establishing seed distribution initialization. Furthermore, we parameterize the puncture needles and seeds, while concurrently constraining the puncture needle angle through the employment of a virtual puncture panel to augment planning algorithm efficiency. We also presented a user interface that includes a range of interactive features, seamlessly integrated with the treatment planning generation function.
Results
The multi‐organ segmentation module, which is trained by 50 cases of in‐house CT scans and 694 cases of publicly available CT scans, achieved average Dice of 0.80 and Hausdorff distance of 5.2 mm in testing datasets. The results demonstrate that knowledge‐based initialization exhibits a marked enhancement in expediting the convergence rate. Our TPS also demonstrates a dominant advantage in dose‐volume‐histogram criteria and execution time in comparison to commercial TPS.
Conclusion
The study proposes an innovative treatment planning system for low‐dose‐rate permanent seed brachytherapy for hepatic malignancies. We show that the generated treatment plans meet clinical requirement.
Background
Type 2 diabetes mellitus (T2DM) is associated with cognitive decline and altered brain structure and function. However, the interhemispheric coordination of T2DM patients is unclear.
...Purpose
To investigate interhemispheric functional and anatomic connectivity in T2DM, and their associations with cognitive performance and endocrine parameters.
Study Type
Prospective.
Subjects
38 T2DM patients and 42 matched controls.
Field Strength/Sequences
3.0 T magnetic resonance imaging (MRI) scanner; magnetization‐prepared rapid acquisition gradient echo sequence; fluid‐attenuated inversion recovery sequence; single‐shot, gradient‐recalled echo‐planar imaging sequence (resting‐state functional MRI); and diffusion‐weighted spin‐echo‐based echo‐planar sequence (diffusion tensor imaging).
Assessment
Voxel‐mirrored homotopic connectivity (VMHC) value was calculated based on the functional images. Fibers passing through the regions with significant VMHC differences were identified using an atlas‐guided track recognition. The mean fractional anisotropy (FA), mean diffusivity (MD), and fiber length were extracted and compared between the two groups. Finally, correlational analyses were performed to examine the relationships between abnormal interhemispheric connectivity, cognitive performances, and endocrine parameters.
Statistical Tests
Two‐sample t‐tests were performed controlling for confounding factors, with partial correlation analysis. False discovery rate (FDR) correction was used for multiple comparisons. A P value <0.05 was considered statistically significant.
Results
T2DM patients exhibited significantly decreased VMHC between bilateral lingual gyrus and sensorimotor cortex. The fibers connecting lingual gyrus in patients showed significantly lower FA (P = 0.011) and shorter fiber length (P < 0.001), while the differences in sensorimotor fibers were insignificant (P = 0.096 for FA, P = 0.739 for fiber length and P = 0.150 for MD). The FA value in the lingual fibers was negatively correlated with insulin resistance (IR) level in T2DM group after FDR correction (R = −0.635).
Data Conclusion
We noted disruptions in interhemispheric coordination in T2DM patients, involving both functional and anatomical connectivities. IR might be a promising therapeutic target in the intervention of T2DM‐related cognitive impairment.
Level of Evidence
2
Technical Efficacy Stage
2
Previous research has shown that type 2 diabetes mellitus (T2DM) is associated with an increased risk of cognitive impairment. Patients with impaired cognition often show decreased spontaneous brain ...activity on resting-state functional magnetic resonance imaging (rs-fMRI). This study used rs-fMRI to investigate changes in spontaneous brain activity among patients with T2DM and to determine the relationship of these changes with cognitive impairment. T2DM patients (n = 29) and age-, sex-, and education-matched healthy control subjects (n = 27) were included in this study. Amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) values were calculated to represent spontaneous brain activity. Brain volume and cognition were also evaluated among these participants. Compared with healthy control subjects, patients with T2DM had significantly decreased ALFF and ReHo values in the occipital lobe and postcentral gyrus. Patients performed worse on several cognitive tests; this impaired cognitive performance was correlated with decreased activity in the cuneus and lingual gyrus in the occipital lobe. Brain volume did not differ between the two groups. The abnormalities of spontaneous brain activity reflected by ALFF and ReHo measurements in the absence of structural changes in T2DM patients may provide insights into the neurological pathophysiology underlying diabetes-associated cognitive decline.
Hearing loss often triggers an inescapable buzz (tinnitus) and causes everyday sounds to become intolerably loud (hyperacusis), but exactly where and how this occurs in the brain is unknown. To ...identify the neural substrate for these debilitating disorders, we induced both tinnitus and hyperacusis with an ototoxic drug (salicylate) and used behavioral, electrophysiological, and functional magnetic resonance imaging (fMRI) techniques to identify the tinnitus-hyperacusis network. Salicylate depressed the neural output of the cochlea, but vigorously amplified sound-evoked neural responses in the amygdala, medial geniculate, and auditory cortex. Resting-state fMRI revealed hyperactivity in an auditory network composed of inferior colliculus, medial geniculate, and auditory cortex with side branches to cerebellum, amygdala, and reticular formation. Functional connectivity revealed enhanced coupling within the auditory network and segments of the auditory network and cerebellum, reticular formation, amygdala, and hippocampus. A testable model accounting for distress, arousal, and gating of tinnitus and hyperacusis is proposed.
Understanding Mott insulators and charge density waves (CDW) is critical for both fundamental physics and future device applications. However, the relationship between these two phenomena remains ...unclear, particularly in systems close to two-dimensional (2D) limit. In this study, we utilize scanning tunneling microscopy/spectroscopy to investigate monolayer 1T-NbSe2 to elucidate the energy of the Mott upper Hubbard band (UHB), and reveal that the spin-polarized UHB is spatially distributed away from the dz2 orbital at the center of the CDW unit. Moreover, the UHB shows a √3 × √3 R30° periodicity in addition to the typically observed CDW pattern. Furthermore, a pattern similar to the CDW order is visible deep in the Mott gap, exhibiting CDW without contribution of the Mott Hubbard band. Based on these findings in monolayer 1T-NbSe2, we provide novel insights into the relation between the correlated and collective electronic structures in monolayer 2D systems.The relationship between Mott state and charge density wave state in two dimensional materials remains unclear. Here, Liu et al. reveal spatial distribution of a Mott-Hubbard band in monolayer 1T-NbSe2 forming a new periodic pattern in addition to the well-known CDW pattern.
Abstract Background Thoracic endovascular aortic repair (TEVAR) has been used in patients with uncomplicated type B acute aortic dissection (B-AAD) to reduce late morbidity and mortality. The ...outcomes of comparisons between TEVAR and best medical treatment (BMT) on patients with uncomplicated type B-AAD are inconsistent in the published reports. Objectives This study sought to further clarify the early and long-term (11-year) outcomes of TEVAR in patients with uncomplicated type B-AAD compared with those with BMT treatment. Methods Between February 2003 and August 2014, 338 patients with uncomplicated type B-AAD were retrospectively identified in 3 tertiary medical centers. Information about baseline characteristics was collected from medical records. Images were retrieved from the imaging archiving system, and the thrombosis status of the false lumen and extent of the dissection were evaluated via computed tomography angiography. Early and late outcomes were recorded and analyzed. Results TEVAR procedures were performed on 184 patients (TEVAR group) and BMT for 154 patients (BMT group). Early events and 30-day mortality were not significantly different between the 2 groups. Patients receiving BMT had significantly higher aortic-related adverse events compared with those in the TEVAR group (p = 0.025). All-cause mortality with TEVAR was significantly lower than that of BMT (p = 0.01). Conclusions This study confirmed the feasibility of TEVAR for uncomplicated type B aortic dissection in the acute setting with fewer aortic-related adverse events and a lower mortality rate compared with BMT.
The augmented intra-operative real-time imaging in vascular interventional surgery, which is generally performed by projecting preoperative computed tomography angiography images onto intraoperative ...digital subtraction angiography (DSA) images, can compensate for the deficiencies of DSA-based navigation, such as lack of depth information and excessive use of toxic contrast agents. 3D/2D vessel registration is the critical step in image augmentation. A 3D/2D registration method based on vessel graph matching is proposed in this study. For rigid registration, the matching of vessel graphs can be decomposed into continuous states, thus 3D/2D vascular registration is formulated as a search tree problem. The Monte Carlo tree search method is applied to find the optimal vessel matching associated with the highest rigid registration score. For nonrigid registration, we propose a novel vessel deformation model based on manifold regularization. This model incorporates the smoothness constraint of vessel topology into the objective function. Furthermore, we derive simplified gradient formulas that enable fast registration. The proposed technique undergoes evaluation against seven rigid and three nonrigid methods using a variety of data - simulated, algorithmically generated, and manually annotated - across three vascular anatomies: the hepatic artery, coronary artery, and aorta. Our findings show the proposed method's resistance to pose variations, noise, and deformations, outperforming existing methods in terms of registration accuracy and computational efficiency. The proposed method demonstrates average registration errors of 2.14 mm and 0.34 mm for rigid and nonrigid registration, and an average computation time of 0.51 s.
To investigate alterations in functional connectivity in the resting brain networks in healthy elderly volunteers and patients with mild, moderate, or severe Alzheimer Disease (AD).
This study was ...approved by the institutional ethics committee, and informed consent was obtained. Forty-six patients with AD and 16 healthy elderly volunteers were prospectively examined. Resting-state functional magnetic resonance imaging was used to detect alterations in posterior cingulate cortex (PCC) functional connectivity through a comparison of the healthy control group with three separate AD groups-mild, moderate, and severe AD. A temporal correlation method was used to obtain PCC connectivity maps.
Dissociated functional connectivity between the PCC and a set of regions, including the visual cortices bilaterally, the inferior temporal cortex, the hippocampus, and especially the medial prefrontal cortex and the precuneus and/or cuneus, was observed in all AD groups. The disruption of connectivity intensified as the stage of AD progression increased. There were also regions that exhibited increased connectivity; these regions extended from left lateralized frontoparietal regions and spread to bilateral frontoparietal regions along with AD progression.
Changes in PCC functional connectivity comprised bidirectional alterations in the resting networks in AD-affected brains, and the impaired resting functional connectivity seemed to change with AD progression. Therefore, alterations in functional connectivity in the default mode network might play a role in the progression of AD.
•Interventional therapy can induce an immunosuppressive microenvironment.•Immune checkpoint inhibitors can increase T cell activity directed against tumor cells.•Interventional therapy combined with ...immune checkpoint inhibitors might lead to a synergistic activity.
Immune checkpoint inhibitors-based immunotherapy offers a new effective modality in the treatment of advanced malignancies. Considering the remarkable efficacy of immune checkpoint inhibitors in clinical trials, the FDA has approved a variety of immune checkpoint inhibitors for the treatment of advanced tumors. However, only limited patients with certain cancers can benefit from monotherapy of immune checkpoint inhibitors. Interventional therapy for cancer can not only destroy the primary tumors, but also regulate the immune system through different mechanisms, which provides a potential possibility for the combination of immune checkpoint inhibitors and interventional modalities in cancer treatment. This article reviews the possible synergistic mechanisms of interventional therapy combined with immune checkpoint inhibitors and summarizes the research progress of the combined therapy in cancer treatment.
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