Targeting for stereotactic radiosurgical thalamotomy based on tremor treatment response

2021 ◽  
pp. 1-8
Author(s):  
Guozhen Luo ◽  
Brent D. Cameron ◽  
Li Wang ◽  
Hong Yu ◽  
Joseph S. Neimat ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Target Location ◽  
Diffusion Tensor ◽  
Red Nucleus ◽  
Target Range ◽  
Slice Thickness ◽  
Dose Volume ◽  
Optimal Target ◽  
Ventral Intermediate Nucleus ◽  
Tractography Data

OBJECTIVE Stereotactic radiosurgery (SRS) treats severe, medically refractory essential tremor and tremor-dominant Parkinson disease. However, the optimal target for SRS treatment within the thalamic ventral intermediate nucleus (VIM) is not clearly defined. This work evaluates the precision of the physician-selected VIM target, and determines the optimal SRS target within the VIM by correlation between early responders and nonresponders. METHODS Early responders and nonresponders were assessed retrospectively by Elements Basal Ganglia Atlas autocontouring of the VIM on the pre–SRS-treatment 1-mm slice thickness T1-weighted MRI and correlating the center of the post–SRS-treatment lesion. Using pre- and posttreatment diffusion tensor imaging, the fiber tracking package in the Elements software generated tremor-related tracts from autosegmented motor cortex, thalamus, red nucleus, and dentate nucleus. Autocontouring of the VIM was successful for all patients. RESULTS Among 23 patients, physician-directed SRS targets had a medial–lateral target range from +2.5 mm to −2.0 mm from the VIM center. Relative to the VIM center, the SRS isocenter target was 0.7–0.9 mm lateral for 6 early responders and 0.9–1.1 mm medial for 4 nonresponders (p = 0.019), and without differences in the other dimensions: 0.2 mm posterior and 0.6 mm superior. Dose–volume histogram analyses for the VIM had no significant differences between responders and nonresponders between 20 Gy and 140 Gy, mean or maximum dose, and dose to small volumes. Tractography data was obtained for 4 patients. CONCLUSIONS For tremor control in early responders, the Elements Basal Ganglia Atlas autocontour for the VIM provides the optimal SRS target location that is 0.7–0.9 mm lateral to the VIM center.

Evaluation of influence of target location on robot repeatability

Robotica ◽  
2000 ◽  
Vol 18 (4) ◽  
pp. 443-449 ◽  
Author(s):  
Raziel Riemer ◽  
Yael Edan
Keyword(s):  
Error Analysis ◽  
Target Location ◽  
Kinematic Model ◽  
Three Dimensional ◽  
Experimental Results ◽  
Target Point ◽  
Analysis Model ◽  
Significant Statistical Difference ◽  
Optimal Target ◽  
Set Up

This paper evaluates the influence of target location on robot repeatability. An experiment was set up to analyze the effect of the three-dimensional target location on robot repeatability. An error-analysis model to determine repeatability based on the robot's kinematic model and known robot parameters was developed. Experimental results indicated that there was a significant statistical difference between repeatability at different locations in the workspace and that the height of the target point influenced repeatability. Experimental results tended to those derived from the error-analysis kinematic model. Hence, to determine the optimal target location, there is no need for extensive experimentation; instead, only a few target points can be sampled and compared to an error-analysis model.

3D DCT Based Filtering of Color and Multichannel Images

2008 ◽  
Vol 67 (15) ◽  
pp. 1369-1392 ◽  
Author(s):  
N. N. Ponomarenko ◽  
V. V. Lukin ◽  
A. A. Zelensky ◽  
P. T. Koivisto ◽  
Karen O. Egiazarian
Keyword(s):  
Multichannel Images

Comparison between different boost dose delivery techniques to the tumor bed of right sided breast cancer patients.

2017 ◽  
Vol 13 (1) ◽  
pp. 4605-4617
Author(s):  
Aly Mahmoud El-Hdidy
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Target Location ◽  
Breast Cancer Patients ◽  
Photon Beams ◽  
Lung Dose ◽  
Dose Volume Histograms ◽  
Tumor Bed ◽  
Boost Dose ◽  
Treatment Plans

Comparisons between three different techniques by which the boost dose was delivered to the tumor bed were carried out , aiming to present the best technique of treatment for right breast cancer patients.In this study, ten right sided breast cancer computed tomography (CT) scans were selected for ten early right breast cancer patients. We made three different treatment plans for each patient CT using three different irradiation techniques to deliver a prescribed boost dose of 10 Gy in 5 fractions to the boost PTV. In the first technique, two tangential photon beams were used, in the second technique we, two oblique photon beams were used and in the third technique, a single electron beam was used. The comparative analyses between the three techniques were performed by comparing the boost PTV- dose volume histograms (DVHs), the ipsilateral breast (right breast) DVHs, the ipsilateral lung (right lung) DVHs and the heart DVHs of the three techniques for each patient. Furthermore the dose that covering 100% , 95% of the volume (D100% , D95%) and the volume covered by 95% of the dose (V95%)of  the boost PTV of all techniques, were calculated for each patient to investigate the dose coverage of the target.Results showed that there were variations of the dose received by tumor bed, right breast and OARs depending on the technique used and the target location and size. A decrease of D100% than 90% of the prescribed dose was observed with the 3rd technique for patients 8, 9 and 10, and was observed with the 2nd technique for patient 5. A reduction of right breast dose was observed when the 3rd technique was use in comparison with the 1st and the 2nd techniques for patients 1, 2, 3, 4, 6 and 8.  Also reduction of right breast was observed when the 2nd technique used in comparison with 1st technique. An increase of lung dose was observed with the 3rd technique for patients 1, 2, 5 and 6, also was observed with 2nd technique in patient 3, 5 and 7. A decrease of lung dose was observed with the 1st technique for patients 2, 4, 5, 6, 7, 8 and 9An individualized treatment, several plans using different irradiation techniques should be developed for each patient individually to reach the best boost PTV dose coverage with minimal OARs’ dose. 

Spatial suppression due to statistical regularities is driven by distractor suppression not by target activation

2018 ◽  
Author(s):  
Michel Failing ◽  
Benchi Wang ◽  
Jan Theeuwes
Keyword(s):  
High Probability ◽  
Target Location ◽  
Target Selection ◽  
Visual Space ◽  
Alternative Interpretation ◽  
Distractor Location ◽  
Target Presentation ◽  
Statistical Regularities ◽  
Low Probability ◽  
Presentation Experiment

Where and what we attend to is not only determined by what we are currently looking for but also by what we have encountered in the past. Recent studies suggest that biasing the probability by which distractors appear at locations in visual space may lead to attentional suppression of high probability distractor locations which effectively reduces capture by a distractor but also impairs target selection at this location. However, in many of these studies introducing a high probability distractor location was tantamount to increasing the probability of the target appearing in any of the other locations (i.e. the low probability distractor locations). Here, we investigate an alternative interpretation of previous findings according to which attentional selection at high probability distractor locations is not suppressed. Instead, selection at low probability distractor locations is facilitated. In two visual search tasks, we found no evidence for this hypothesis: neither when there was only a bias in target presentation but no bias in distractor presentation (Experiment 1), nor when there was only a bias in distractor presentation but no bias in target presentation (Experiment 2). We conclude that recurrent presentation of a distractor in a specific location leads to attentional suppression of that location through a mechanism that is unaffected by any regularities regarding the target location.

The Novel TEM Sample Preparation Approach for Targeted via with Barrier/Cu Seed Layer Inspection

2009 ◽  
Author(s):  
Wen-Fei Hsieh ◽  
Shih-Hsiang Tseng ◽  
Bo Min She
Keyword(s):  
Sample Preparation ◽  
Cross Section ◽  
Seed Layer ◽  
Target Location ◽  
Process Development ◽  
Process Integration ◽  
Ion Beam ◽  
Main Tool ◽  
Dual Beam ◽  
Sample Preparation Procedure

Abstract In this study, an FIB-based cross section TEM sample preparation procedure for targeted via with barrier/Cu seed layer is introduced. The dual beam FIB with electron beam for target location and Ga ion beam for sample milling is the main tool for the targeted via with barrier/Cu seed layer inspection. With the help of the FIB operation and epoxy layer protection, ta cross section TEM sample at a targeted via with barrier/Cu seed layer could be made. Subsequent TEM inspection is used to verify the quality of the structure. This approach was used in the Cu process integration performance monitor. All these TEM results are very helpful in process development and yield improvement.

Differential Drug Target Selection in Blood Coagulation: What can we get from Computational Systems Biology Models?

2020 ◽  
Vol 26 (18) ◽  
pp. 2109-2115 ◽  
Author(s):  
Mikhail A. Panteleev ◽  
Anna A. Andreeva ◽  
Alexey I. Lobanov
Keyword(s):  
Blood Coagulation ◽  
Biological Network ◽  
Target Selection ◽  
Anticoagulation Therapy ◽  
Differential Regulation ◽  
Coagulation Cascade ◽  
Computational Systems Biology ◽  
Analysis Strategies ◽  
Optimal Target ◽  
Computational Systems

Discovery and selection of the potential targets are some of the important issues in pharmacology. Even when all the reactions and the proteins in a biological network are known, how does one choose the optimal target? Here, we review and discuss the application of the computational methods to address this problem using the blood coagulation cascade as an example. The problem of correct antithrombotic targeting is critical for this system because, although several anticoagulants are currently available, all of them are associated with bleeding risks. The advantages and the drawbacks of different sensitivity analysis strategies are considered, focusing on the approaches that emphasize: 1) the functional modularity and the multi-tasking nature of this biological network; and 2) the need to normalize hemostasis during the anticoagulation therapy rather than completely suppress it. To illustrate this effect, we show the possibility of the differential regulation of lag time and endogenous thrombin potential in the thrombin generation. These methods allow to identify the elements in the blood coagulation cascade that may serve as the targets for the differential regulation of this system.

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