Wire Markers Research Articles

Demystifying the Quandary of Ostial Stenting.

Accurate stent placement is known to be hampered by the anatomical nature of percutaneous coronary intervention (PCI) of ostial lesions, such as aorta-ostial lesions and Medina 001 bifurcation lesions. The Ostial Pro device, the aorta floating wire technique, the stent pull-back technique, the Szabo (tail-wire) techniques, the marker wire technique, the T-stent and small protrusion technique, the cross-over 1-stent technique, and new dedicated ostial stents are some of the techniques used to achieve perfection in precise ostial stent placement. The current state of knowledge about ostial PCI and novel approaches for optimizing these procedures are compiled in this review.

Correlation between AI-based CT organ features and normal lung dose in adjuvant radiotherapy following breast-conserving surgery: a multicenter prospective study

BackgroundRadiation pneumonitis (RP) is one of the common side effects after adjuvant radiotherapy in breast cancer. Irradiation dose to normal lung was related to RP. We aimed to propose an organ features based on deep learning (DL) model and to evaluate the correlation between normal lung dose and organ features.MethodsPatients with pathology-confirmed invasive breast cancer treated with adjuvant radiotherapy following breast-conserving surgery in four centers were included. From 2019 to 2020, a total of 230 patients from four nationwide centers in China were screened, of whom 208 were enrolled for DL modeling, and 22 patients from another three centers formed the external testing cohort. The subset of the internal testing cohort (n = 42) formed the internal correlation testing cohort for correlation analysis. The outline of the ipsilateral breast was marked with a lead wire before the scanning. Then, a DL model based on the High-Resolution Net was developed to detect the lead wire marker in each slice of the CT images automatically, and an in-house model was applied to segment the ipsilateral lung region. The mean and standard deviation of the distance error, the average precision, and average recall were used to measure the performance of the lead wire marker detection model. Based on these DL model results, we proposed an organ feature, and the Pearson correlation coefficient was calculated between the proposed organ feature and ipsilateral lung volume receiving 20 Gray (Gy) or more (V20).ResultsFor the lead wire marker detection model, the mean and standard deviation of the distance error, AP (5 mm) and AR (5 mm) reached 3.415 ± 4.529, 0.860, 0.883, and 4.189 ± 8.390, 0.848, 0.830 in the internal testing cohort and external testing cohort, respectively. The proposed organ feature calculated from the detected marker correlated with ipsilateral lung V20 (Pearson correlation coefficient, 0.542 with p < 0.001 in the internal correlation testing cohort and 0.554 with p = 0.008 in the external testing cohort).ConclusionsThe proposed artificial Intelligence-based CT organ feature was correlated with normal lung dose in adjuvant radiotherapy following breast-conserving surgery in patients with invasive breast cancer.Trial registrationNCT05609058 (08/11/2022).

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This review examines the reported impacts of three major linear infrastructure developments, namely railways, roads and power lines on avifauna. These infrastructures are proliferating worldwide posing serious threats to wildlife including avifauna. The major impacts involved with linear infrastructures are habitat degradation, fragmentation, direct mortality by collision and electrocution. The factors affecting collision mortality can be divided into intrinsic and extrinsic factors. The intrinsic factors include species morphology and species behavior whereas the extrinsic factors are the external factors such as weather, landscape features and the technical aspects of the infrastructure. Power lines affect a large number of birds, killing more than one billion birds globally each year. Studies suggest the implementation of anti-collision devices such as wire markers; flight diverters and physical barriers like trees, diversion poles or noise barriers are effective mitigation measures to reduce bird mortality due to the linear infrastructures. Therefore, understanding the overall impact of linear infrastructures is crucial for effectively managing their impacts on avifauna and helping make future developments less destructive and more sustainable.

TCTAP C-075 Retrograde Kissing Wire Marker as a Plan B of Antegrade CTO Procedure

TCTAP C-075 Retrograde Kissing Wire Marker as a Plan B of Antegrade CTO Procedure

The Evaluation of a Cost-Effective Method for Tumour Marking Prior to Neo-Adjuvant Chemotherapy Using Silver Rods.

The lack of objective documentation of pre-neoadjuvant chemotherapy (NAC) tumour margins is a major constraint in performing safe breast conserving surgery (BCS) in patients with breast cancer. Using a novel method of marking pre-NACT tumour margins with indigenous silver wire markers, this retrospective observational study attempted to assess the feasibility of safe BCS in breast cancer patients by performing excision wide of the marked pre-NACT margins. This retrospective observational study was conducted on breast cancer patients who were attending our oncology centre between May, 2015 and April, 2022. All patients had received NAC followed by surgery as recommended by our multidisciplinary team. All the patients had a primary operable solitary breast cancer. We used radiopaque metallic rods made from silver to localize tumour margins prior to NAC. Sixty-four breast cancer patients were included; none had marker-related complications. Following NAC, BCS could be easily performed in 60 patients guided by the silver markers, which were used as temporary implants and removed during surgery. Only 2 patients were seen with positive margins and were converted to mastectomy. Breast cancer localization using sterile silver markers before the initiation of NAC is safe, easy, inexpensive, and effective, causing no morbidity or significant pain to the patients.

Conversational hypnosis versus standard of care to reduce anxiety in patients undergoing marker placement under radiographic control prior to breast cancer surgery: A randomized, multicenter trial.

Surgery is a cornerstone of breast cancer management. Prior to surgery, a wire marker is placed at the site of the tumor, to enable the surgeon to accurately localize the lesion during later surgery. This procedure can generate considerable anxiety for many patients. We investigated the value of conversational hypnosis (CH) in reducing anxiety in patients undergoing preoperative wire placement under radiographic control. Randomized, multicentre study in 7 centers in France. Inclusion criteria were patients aged >18 years with an Eastern Cooperative Oncology Group performance status ≤2, scheduled to undergo preoperative wire placement in one or several breast lesions. Patients were randomized in a 1:1 ratio, stratified by center to undergo preoperative wire placement with or without the use of CH by a radiological technician trained in the CH technique. The primary endpoint was the percentage of patients with an anxiety score ≥ 6 on a visual analog scale ranging from 0 (absence of anxiety) to 10 (maximal anxiety). Secondary endpoints were pain score, perceived duration reported by the patient, technician satisfaction with their relationship with the patient, and ease of marker insertion reported by the radiologist. Semi-structured interviews were performed with patients to assess their perception of the marker placement procedure. The trial was prematurely interrupted for futility after a planned interim analysis after accrual of 167 patients, i.e., half the planned sample size. Prior to marker placement, 29.3% (n = 24) of patients in the control group had an anxiety score ≥ 6, versus 42.3% (n = 33) in the CH group (p = 0.08). After marker placement, the change of anxiety score was not significantly different between groups (11.0% (n = 9) versus 14.3% (n = 11), p = 0.615). There was no significant difference in any of the secondary endpoints. In the interviews, patients from both groups frequently spoke of a feeling of trust. This study failed to show a benefit of conversational hypnosis on anxiety in patients undergoing marker placement prior to surgery for breast cancer. The fact that some caregivers had learned this personalized therapeutic communication technique may have had a positive impact on the whole caregiving team. The study was registered with ClinicalTrials.gov (NCT02867644).

PHSPP02 Presentation Time: 2:40 PM: Automated Channel Identification for Efficient Brachytherapy Treatment Planning

<h3>Purpose</h3> For interstitial brachytherapy, channel reconstruction during the process of brachytherapy treatment planning can be an arduous and time-consuming task, which becomes more difficult and error-prone when 20 to 30 different catheters with curvatures are involved and overlap in 3D in the patient anatomy. The goal of this project is to develop an artificial intelligence-based approach for automated channel identification using patient CT scans, reducing both the time and potential for human error in brachytherapy treatment planning. <h3>Materials and Methods</h3> Three sets of CT scans were used as well as a baseline model for training, which were acquired with a set of binary-coded "dummy wires" markers <i>in situ</i>. Each of the 12 available dummy wires was designed with a unique pattern of radio-opaque markers and/or spacing strands which was mapped to a channel identification array. An identification algorithm was developed which involved first manually specifying the 3D DICOM coordinates of the centroids of each of the marker strands within the dummy wires. A nearest neighbor search was performed using a k-d tree method for each centroid acting as a potential starting point within a channel. Using the knowledge from the baseline model of each of the 12 potential dummy wire markers, the system predicted the most probable trajectory through the centroids. Then, to assign the proper channel number, the identified pattern of the applicable neighboring points was correlated with the channel identification array defined previously. This process was repeated until the entire configuration of channel identities was determined. Finally, a process of elimination was used to output the correct channel labels and locations. <h3>Results</h3> In this feasibility study, the developed algorithm was able to suitably provide channel identities and return the locations to the user when the proper centroid locations were input into the model. The model ran within seconds and required no training data other than the layout and spacing of the strands within the coded dummy-wire marker system. The final output was able to be graphically represented as labeled reconstructions of the catheters in a 3D space. <h3>Conclusions</h3> The outcomes of this preliminary work suggested that there is a future for automated aid in the channel identification process based on coded dummy-wire markers for more efficient treatment planning in brachytherapy. Using only the centroids of the markers, the channels could be accurately reconstructed. Future work will involve creating a 3D CT scan-based image detection algorithm to automate the process of defining the centroid locations without any <i>a priori</i> knowledge.

Marker Wire Technique for Precise LAD Ostium Stenting

The ostial left anterior descending coronary artery (LAD) lesion is an important target for coronary revascularization because its location subtends a large territory of myocardium1. Accurate stent placement is, however, mandatory for optimal results, but this is often difficult to achieve with the guidance of traditional angiography. We present a case of precise LAD ostium stenting with simple innovative marker wire technique. Ostial PCI requires very precise stent positioning to obtain full lesion coverage, yet avoid unnecessary proximal extension which may result in obstruction of major vessels. Excessive stent movement occurs with cardiac contraction. Our case shows that with simple marker wire technique, precise LAD ostium stenting can be done with good results.

Zero contrast angioplasty of LAD ostium by marker wire technique

Zero contrast Angioplasty brings new hope and new era in treating patient with chronic kidney disease (CKD). It is technically very promising approach for the prevention of contrast induced nephropathy (CIN). Contrast induced nephropathy (CIN) is a common iatrogenic complication associated with adverse outcome including need for Renal replacement therapy (RRT). Zero contrast PCI is creating new era in the field of coronary intervention specially treating those patients with CKD who are suffering from refractory angina and not indicated or fit for Cardiac Bypass surgery. Besides treating simple lesion, challenging case like LAD ostial PCI with placement of stent precisely in LAD ostium can be done by zero contrast or minimal contrast. In this case, for the first time marker wire technique had been used with applying some innovative approach in placing stent precisely in ostium successfully.

Multidisciplinary approach to endobronchial HDR brachytherapy as an alternative to external beam radiation for palliating malignant airway obstruction.

132 Background: Concerns over the safety of high-dose-rate (HDR) endobronchial brachytherapy (EBB) has limited its widespread use in palliating pulmonary airway obstruction. Morbidity following EBB is commonly attributed to fatal hemoptysis and fistula formation. We implemented a procedure to deliver EBB under general anesthesia to minimize procedure risks, while maintaining treatment effectiveness. We hereby report outcomes of consecutive patients treated using this approach to palliate airway obstruction. Methods: We retrospectively reviewed charts of consecutive patients treated with EBB. Treated patients had obstructive lesions &gt;2cm distal to the carina and central structures, who were deemed candidates for EBB by a multidisciplinary team of interventional pulmonologists (IP) and radiation oncologists (RO). All patients were treated under general anesthesia. Bronchoscopy and localization of target lesions was performed by IP. HDR catheters carrying a marker wire were advanced past obstructive lesion. CT simulation was performed to confirm catheter placement, and perform CT-based 3D treatment planning. A dose of 6 -7 Gy/fraction was prescribed at 1 cm from catheter surface. Results: 25 patients (ages 29 -71, mean 52 years) were treated with EPP. 5 had previously received external beam radiation (EBRT) and 3 had concurrent EBRT and EPP. Overall, a total of 76 EBB treatments were performed, with a median of 3 weekly fractions per patient (range 1-6) to total dose of 18Gy. There were no incidences of major bleeding (&gt;50 mL) or fatal hemoptysis in the 30 days following EPP. Moreover, there were no cases of severe (Grade 3 or higher) CTCAE toxicity reported. After a median follow up of 30 months (range 4-42) only 1 out of 17 patients treated with EPP alone required additional EBRT for airway obstruction, 12 months following EPP. Conclusions: Our data suggest the safety and efficacy of an expert multidisciplinary approach to palliating pulmonary airway obstruction using EPP. This approach provides effective palliation of airway obstruction and decreased the need for additional EBRT in majority of treated patients.

Wednesday, September 26, 2018 1:00 PM – 2:00 PM Navigation and Intraoperative Monitoring: 49. Novel technology for C-arm based pedicle navigation

Wednesday, September 26, 2018 1:00 PM – 2:00 PM Navigation and Intraoperative Monitoring: 49. Novel technology for C-arm based pedicle navigation

Radiation Dose to Heart and Great Vessels During Esophageal HDR Brachytherapy

Esophageal cancer patients’ initial treatment is high dose rate (HDR) intraluminal brachytherapy. The treatments are often given as 1800cGy over 3 fractions. Currently, post-treatment CT scans are not required for brachytherapy. During a given treatment fraction, the cranial and caudal extent of the disease is identified under fluoroscopic guidance and a predetermined treatment plan is selected based on the clinical observations. A fraction dose of 600cGy is prescribed at 1cm from the centre axis of the treatment catheter. This will inevitably result in the heart being irradiated. The aim of this study is to assess radiation dose received by the heart and great vessels during HDR intraluminal brachytherapy of esophageal cancers. This study evaluated the treatment plans of 11 patients who underwent a CT scan with the catheter in place following intraluminal HDR brachytherapy of the esophagus. A marker wire was placed into the catheter for better visualization. Post-treatment CT data were imported into the Eclipse BrachyVision planning system. Contours of heart and great vessels (aorta, pulmonary artery, superior vena cava) were drawn. The catheter was digitized and all treatment parameters were reproduced in the planning system resulting in the delivered 3-dimensional dose distribution. Homogeneous and heterogeneous dose calculations were performed and the resulting DVHs analyzed for maximum point doses and volume doses. Comparisons were made with Timmerman’s 3-fraction hypofractionated dose constraint recommendations for normal tissues. Volume doses of organs at risk (OARs) were well below the Timmerman dose constraints; however, maximum point doses calculated in the heart greatly exceeded the respective constraint. The dose to the heart was related to the proximity of the heart to the tumour and hence treatment catheter. Differences in calculated OAR doses using homogeneous and heterogeneous dose calculation engines were minimal. The study’s assessment of dose received to the heart and great vessels validated the accuracy of standardized planning of esophageal HDR brachytherapy. Therefore, current protocols without post-treatment CT are satisfactory and heterogeneous dose calculations are not necessary.

Correction of radiographic measurements of acetabular cup wear for variations in pelvis orientation.

Radiographic measurement of two-dimensional acetabular cup wear is usually carried out on a series of follow-up radiographs of the patient’s pelvis. Since the orientation of the pelvis might not be consistent at every X-ray examination, the resulting change in view of the wear plane introduces error into the linear wear measurement. This effect is amplified on some designs of cup in which the centre of the socket is several millimetres below the centre of the cup or circular wire marker. This study describes the formulation of a mathematical method to correct radiographic wear measurements for changes in pelvis orientation. A mathematical simulation of changes in cup orientation and wear vectors caused by pelvic tilt was used to confirm that the formulae corrected the wear exactly if the radiographic plane of the reference radiograph was parallel to the true plane of wear. An error analysis showed that even when the true wear plane was not parallel to the reference radiographic plane, the formulae could still provide a useful correction. A published correction formula was found to be ineffective.

Investigation of electron boost radiotherapy in patients with breast cancer: Is a direct electron field optimal?

PurposeHistorically, electron boost dose mainly was delivered by a direct field in adjuvant radiotherapy of breast cancer. In this prospective study, we investigated direct electron field, in terms of optimal coverage of tumour bed volume following localization using ultrasound and surgical clips. Material and methodsFirst, for all 24 patients, a breast sonographer drew perimeter of tumour bed on the breast skin. Then an electron boost field was outlined on the demarcated territory, and a lead wire marker compatible with CT scan was placed on the field borders by a 2cm margin. After CT scan simulation, all patients underwent adjuvant whole breast irradiation with 3D-conformal radiotherapy to 50Gy in 25 fractions. Then for boost radiotherapy, lead wire in CT images was countoured as electron boost field. Also, the tumour bed was contoured based on surgical clips (true clinical target volume and true planning target volume). Electron treatment planning was done for electron boost field. Finally isodose coverages for true planning target volume investigated. ResultsOn average, 16.68% of clips planning target volume (true planning target volume; range: 0.00 to 95%) received 90% oor more of the prescribed dose when the electron treatment plan was made. Isodose curves does not provide adequate coverage on the tumour bed (clips planning target volume) when electron boost treatment planning was generated for electron boost field (en face electron field). In fact, a part of target (planning target volume-c) is missed and more doses is absorbed in normal tissue. ConclusionsElectron boost treatment planning (an en face electron field) following tumour bed localization using ultrasonography does not provide an optimized coverage of tumour bed volume.

An in vitro study to evaluate the accuracy of orthopantomograph as an aid to determine condylar guidance.

Purpose:The study was conducted to evaluate the accuracy of orthopantomograph (OPG) as an aid to determine condylar guidance.Methodology:The condylar guidance was measured using the impressions of glenoid fossae and radiographs (OPG) on thirty dried human skulls. Frankfurt horizontal plane (FHP) was used as a reference plane in both the methods and wire markers were adapted to make the contours of glenoid fossae discernible for both the methods. The condylar inclination angle was measured between FHP and a line joining the most concave point on the glenoid fossa with the most inferior point on the articular eminence on both right and left sides.Results:Pearson correlation was used for statistical analysis, and it showed a strong correlation between anatomic and radiographic methods (r = 0.864 for the left side, r = 0.873 for the right side) as well as between right and left sides (r = 0.830). The data were also subjected to regression analysis (linear and panel estimation approach) which showed that OPG could be effectively used to predict the condylar guidance (r2 = 0.6160).Conclusion:Although OPG shows a higher value than anatomic method, it can be used as an aid to set condylar guidance on semi-adjustable articulator.

Technique for treating complex aneurysms with Hercules stent graft modified by the surgeon

Endovascular treatment of thoracoabdominal aneurysms with fenestrated stent grafts expands its applicability because of good technical results. However, stent graft customization requires an average of 6 to 12 weeks, which makes this technique ineligible for symptomatic or ruptured aneurysms. Authors advocate perioperative fenestration by the surgeon, allowing this technique to be used for emergency cases with good results and favorable prognosis. This article describes a technique for intraoperative changes of the Hercules stent graft (MicroPort Scientific Corporation, Shanghai, China) to include the ostia of visceral arteries by making fenestrations and scallops, with a temporary diameter-reducing wire as a further modification to facilitate positioning and catheterization of fenestrations with guidewires.

Investigating the use of image thresholding in brachytherapy catheter reconstruction

This study evaluated the accuracy of image thresholding in the reconstruction of catheters in brachytherapy treatment planning systems. Six test cases including four planar catheter configurations, an interstitial prostate and an intracavitary treatment plan were made use of in this study. The four planar CT scanned catheter arrangements included; catheters placed approximately 1, 0.5cm apart, catheters closely arranged in a plan (<0.5cm apart) and a loop arrangement. The intracavitary plan consisted of catheters arranged inside a mould configuration. All reconstruction methods were based on tracking wire markers placed inside the plastic catheters. Each of these catheter arrangements was reconstructed using an existing window adjustment technique (manual reconstruction) in the treatment planning system followed by a CT-based automated thresholding technique available in the same planning system. A corresponding reconstructed catheter was created using a segmented catheter structure using image thresholding from another planning system within the same department. Co-ordinates from all the reconstructed catheters were compared against each other to assess the geometric shift between manual and threshold based reconstruction on each transaxial image using in-house software and the maximum variations were recorded for assessment. It was observed in general that automated thresholding technique could assist in catheter reconstruction for catheters which are greater than 0.5cm apart. The segmented thresholding method reported smaller variations when compared to the manual reconstruction using window adjustment technique. Automated reconstruction saves time in the brachytherapy planning, however it was noted that it is not feasible for closely spaced catheters. Segmented catheter reconstruction although time consuming, did provide a better alternative in most cases.

Quality Assurance of Sterile, Single Use Savi(TM) Applicators at the Time of Simulation to Verify That Channel Positions Do Not Deviate from Their Expected Locations

Quality Assurance of Sterile, Single Use Savi(TM) Applicators at the Time of Simulation to Verify That Channel Positions Do Not Deviate from Their Expected Locations

Intravascular US–Guided Portal Vein Access: Improved Procedural Metrics during TIPS Creation

PurposeTo evaluate transjugular intrahepatic portosystemic shunt (TIPS) outcomes and procedure metrics with the use of three different image guidance techniques for portal vein (PV) access during TIPS creation. Materials and MethodsA retrospective review of consecutive patients who underwent TIPS procedures for a range of indications during a 28-month study period identified a population of 68 patients. This was stratified by PV access techniques: fluoroscopic guidance with or without portography (n = 26), PV marker wire guidance (n = 18), or intravascular ultrasound (US) guidance (n = 24). Procedural outcomes and procedural metrics, including radiation exposure, contrast agent volume used, procedure duration, and PV access time, were analyzed. ResultsNo differences in demographic or procedural characteristics were found among the three groups. Technical success, technical success of the primary planned approach, hemodynamic success, portosystemic gradient, and procedure-related complications were not significantly different among groups. Fluoroscopy time (P = .003), air kerma (P = .01), contrast agent volume (P = .003), and total procedural time (P = .02) were reduced with intravascular US guidance compared with fluoroscopic guidance. Fluoroscopy time (P = .01) and contrast agent volume (P = .02) were reduced with intravascular US guidance compared with marker wire guidance. ConclusionsIntravascular US guidance of PV access during TIPS creation not only facilitates successful TIPS creation in patients with challenging anatomy, as suggested by previous investigations, but also reduces important procedure metrics including radiation exposure, contrast agent volume, and overall procedure duration compared with fluoroscopically guided TIPS creation.

Improved source path localisation in ring applicators and the clinical impact for gynecological brachytherapy.

PurposeThe path of subsequent dwell positions of an afterloader source being moved through a ring applicator for cervix cancer brachytherapy deviates from an ideal circle and the position of marker wires. This can lead to deviations of several millimetres between real and assumed dwell positions for treatment planning with simplified source path models. The aim of this study was to test video- and autoradiography-based methods for source path determination, and to study the influence of dwell position accuracy on dose-volume histogram (DVH)-parameters.Material and methodsVideos of the exact motion of the source wire through three different (r = 26, 30, 34 mm) computed tomography/magnetic resonance (CT/MR) compatible plastic ring applicators were recorded. Observed dwell positions covering the whole length of each applicators channel were used to adjust the circular source path model. The agreement of the true source positions derived from video analysis with those of the corrected circular source path was verified using autoradiography. The impact of an accurate source path definition on dose planning was analysed by simulating clinically relevant uncertainties in 10 clinical treatment plans.ResultsDepending on the ring size, source path diameters had to be increased by 0.5-1.0 mm in order to achieve acceptable maximum differences between observed and corrected dwell positions (1.3-2.0 mm). Autoradiography analysis showed a positional accuracy within ± 3 mm (extended standard deviation k = 2). For shifts of ± 2.5 mm for even all dwell positions, the systematic and random variation of the D2cm3 for bladder, rectum, and sigmoid was within 3%, while the impact on DVH uncertainties was much smaller for clinical target volume (CTV)HR and gross tumour volume (GTV).ConclusionsIt is strongly advised to verify the real source path for ring applicators during acceptance testing in order to assure accurate source path definition and dose planning. Autoradiography can be used for source path verification with acceptable accuracy for treatment planning and dose reporting.