Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.405
Filtrar
1.
Br J Radiol ; 93(1114): 20190710, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32706981

RESUMO

OBJECTIVE: Limited visibility of post-resection muscle-invasive bladder cancer (MIBC) on CT hinders radiotherapy dose escalation of the residual tumour. Diffusion-weighted MRI (DW-MRI) visualises areas of high tumour burden and is increasingly used within diagnosis and as a biomarker for cancer. DW-MRI could, therefore, facilitate dose escalation, potentially via dose-painting and/or accommodating response. However, the distortion inherent in DW-MRI could limit geometric accuracy. Therefore, this study aims to quantify DW-MRI distortion via imaging of a bladder phantom. METHODS: A phantom was designed to mimic MIBC and imaged using CT, DW-MRI and T2W-MRI. Fiducial marker locations were compared across modalities and publicly available software was assessed for correction of magnetic susceptibility-related distortion. RESULTS: Fiducial marker locations on CT and T2W-MRI agreed within 1.2 mm at 3 T and 1.8 mm at 1.5 T. The greatest discrepancy between CT and apparent diffusion coefficient (ADC) maps was 6.3 mm at 3 T, reducing to 1.8 mm when corrected for distortion. At 1.5 T, these values were 3.9 mm and 1.7 mm, respectively. CONCLUSIONS: Geometric distortion in DW-MRI of a model bladder was initially >6 mm at 3 T and >3 mm at 1.5 T; however, established correction methods reduced this to <2 mm in both cases. ADVANCES IN KNOWLEDGE: A phantom designed to mimic MIBC has been produced and used to show distortion in DW-MRI can be sufficiently mitigated for incorporation into the radiotherapy pathway. Further investigation is therefore warranted to enable individually adaptive image-guided radiotherapy of MIBC based upon DW-MRI.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Aumento da Imagem/métodos , Imagens de Fantasmas , Radioterapia Guiada por Imagem , Neoplasias da Bexiga Urinária/diagnóstico por imagem , Neoplasias da Bexiga Urinária/radioterapia , Marcadores Fiduciais , Humanos , Invasividade Neoplásica , Tomografia Computadorizada por Raios X , Neoplasias da Bexiga Urinária/patologia
2.
Am Surg ; 86(8): 1029-1031, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32721172

RESUMO

BACKGROUND: Breast cancer is the most commonly diagnosed noncutaneous malignancy and remains the second leading cause of cancer deaths in women. The Savi Scout (Cianna Medical, Merit Medical Systems, Inc. South Jordan, UT) is a wireless, nonradioactive, wave reflection implant system that enables surgeons to remove targeted breast lesions. Our study aims to be the largest comparison of wire and Savi Scout localization techniques for positive margin, complication, and reoperation rates. METHODS: Single-institution retrospective review of 512 patients that had Savi Scout Surgical Guidance System breast lesion biopsy or wire localized breast biopsy from May 2017 to December 2018. A RedCaps database was created and reviewed for outcomes. RESULTS: For 320 Savi scout patients, margins were positive or less than 1 mm in 18 cases (5.6%). 17 (5.3%) patients required reoperation. Surgical site occurrence was found in 7 (2.1%) patients, and 2 patients required intervention (0.6%). For 175 wire localization patients, margins were positive or less than 1 mm in 24 patients, and all required reoperation (13.7%). A surgical site occurrence was found in 13 (7.4%) patients and 5 patients required intervention (2.8%). DISCUSSION: In our series, the Savi Scout localization system resulted in a lower rate of positive margins, reoperation, and surgical site occurrence. These data suggest that Savi Scout localization is a reasonable replacement to wire localization for breast lesions and might produce superior results.


Assuntos
Neoplasias da Mama/cirurgia , Mama/patologia , Carcinoma Ductal de Mama/cirurgia , Marcadores Fiduciais , Mastectomia Segmentar/métodos , Radar , Cirurgia Assistida por Computador/instrumentação , Adulto , Idoso , Biópsia , Mama/diagnóstico por imagem , Mama/cirurgia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Margens de Excisão , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Cirurgia Assistida por Computador/métodos
3.
Br J Radiol ; 93(1111): 20200241, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32463291

RESUMO

OBJECTIVE: This study evaluated the performance of the novel liquid fiducial marker (BioXmark®) in IGRT for bladder cancer. METHODS: 20 patients with muscle invasive bladder cancer were entered in this prospective, single center, Phase I-II study. The novel BioXmark® liquid markers were injected around the tumor using a flexible cystoscopy. Visibility and stability of the markers were evaluated on planning-CT and CBCT. Prospectively defined threshold for success was set at a visibility of 75%. RESULTS: In total, 76 markers were implanted in 20 patients. Of those, 60 (79% 95% CI ± 9%) were visible on CT scan. Due to the learning curve of the technique, the visibility improved in the last 75% of patients (86% visibility) compared to the first 25% of patients with 58% visibility. Concerning stability of the BioXmark® marker, all visible markers after CT acquisition were still detectable at the last CBCT without displacement. In 15/20 (75%) of the patients, three or more markers were visible on CT. No BioXmark® related adverse events were reported. CONCLUSION: The success rate of this novel fiducial marker was 79%, which is above the prospectively defined threshold rate. A distinct learning curve of the injection of the liquid marker was seen over the study period. The marker showed sustained visibility and positional stability during treatment phases and also appears to be safe and easy to inject. ADVANCES IN KNOWLEDGE: This novel liquid BioXmark® marker seems to be a very promising tool in daily-adaptive IGRT for bladder preserving chemoradiotherapy in muscle invasive bladder cancer.


Assuntos
Marcadores Fiduciais , Neoplasias Musculares/radioterapia , Neoplasias da Bexiga Urinária/radioterapia , Idoso , Idoso de 80 Anos ou mais , Cistoscopia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Segurança do Paciente , Estudos Prospectivos , Radioterapia Guiada por Imagem/métodos , Resultado do Tratamento
4.
Curr Gastroenterol Rep ; 22(6): 27, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32350629

RESUMO

PURPOSE OF REVIEW: The aim of this review is to evaluate the emerging role of endoscopic ultrasound (EUS) in the guidance of tumor-targeted therapies for patients with pancreatic cancer (PC). RECENT FINDINGS: EUS-guided ablation, brachytherapy, fiducial marker placement, and antitumor agent injection have been described to date. EUS-guided fiducial placement for SBRT in pancreatic cancer has entered the clinical practice and is performed at many centers clinically without a research protocol. EUS-guided brachytherapy and RFA have been shown to be feasible and safe procedures, and potentially offer local disease control. Other potential techniques of EUS-guided treatment of pancreatic cancer are still considered experimental, with many of them appearing to be safe and reasonably well tolerated. However, their effectiveness and exact role in oncological treatment have yet to be established. Clinical trials with many of the techniques/agents described are underway and multicentric randomized trials with prospective design are eagerly awaited.


Assuntos
Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/terapia , Endossonografia/métodos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/terapia , Técnicas de Ablação/métodos , Antineoplásicos/administração & dosagem , Braquiterapia , Marcadores Fiduciais , Humanos , Injeções Intralesionais , Ultrassonografia de Intervenção/métodos
5.
Phys Med Biol ; 65(13): 13NT02, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32428876

RESUMO

A dynamically compressible phantom of the human abdomen that simulates organ motion with breathing is being developed for possible testing of image-gated beam delivery in radiotherapy. The polyvinyl chloride plastisol (PVCP) phantom features a cavity that can contain a deformable normoxic polyacrylamide gel (nPAG) dosimeter that is intended for use with MRI to provide dosimetric data. The phantom has been improved by the inclusion of new components that are more realistic anatomically and exhibit CT values similar to those of the tissues they mimic. Component organs were made from 3D-printed molds developed from CT contours of a real patient and their radiodensities adjusted by varying the mass ratios of the PVCP hardener and softener during manufacture. To make the phantom more compatible with ultrasound imaging a graphite scatterer was mixed into some of the phantom components to produce a background speckle pattern. This provided contrast between the body and a moving anatomical target intended for motion tracking. Phantom insert motion magnitude and repeatibility was assessed using CT by imaging two phantom inserts, one containing fiducial markers and the other containing iodinated gelatin, at the same position after repeated cycles of deformation. The maximum motion of a phantom fiducial at the position of the phantom treatment target was found to be 12.2 mm. The phantom design resulted in dosimeter motion with a point-to-point repatability within 0.3 mm on average and contour repeatability resulting in Dice coefficients exceeding 0.98 on average.


Assuntos
Abdome/diagnóstico por imagem , Fracionamento da Dose de Radiação , Imagens de Fantasmas , Radioterapia Guiada por Imagem/instrumentação , Marcadores Fiduciais , Humanos , Movimento , Radiometria , Reprodutibilidade dos Testes , Respiração , Tomografia Computadorizada por Raios X , Ultrassonografia
6.
Br J Radiol ; 93(1111): 20190956, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32302215

RESUMO

OBJECTIVE: To compare two kinds of metal markers for preoperative localization of ground glass nodules (GGNs). METHODS: We retrospectively investigated data from 198 cases of GGN localization and compared the success rate and complications of both approaches. RESULTS: In the hook wire and coil groups, the success rates of CT-guided localization for GGNs were 99.2 and 98.7%, respectively (p = 1.000). The success rates of video-assisted thoracoscopic surgery in both groups were 100% without transthoracic surgery. The post-localization complication rates in the hook wire group and coil group were 36.9 and 32.9% (p = 0.568), and the postoperative complication rates in the hook wire and coil groups were 13.9 and 11.8%, respectively (p = 0.672). CONCLUSIONS: Preoperative localization of GGNs with both hook wire and coil methods proved to be useful and effective. Both methods have acceptable preoperative and postoperative complication rates, but the localization and operation times were shorter for the hook wire group than the coil group. ADVANCES IN KNOWLEDGE: Most of previous articles studied a single preoperative localization method. Few studies have compared the preoperative and postoperative methods for metal markers. This paper compared two preoperative localization methods for GGNs to provide clinical guidance.


Assuntos
Neoplasias Pulmonares/cirurgia , Nódulos Pulmonares Múltiplos/cirurgia , Cirurgia Torácica Vídeoassistida/métodos , Feminino , Marcadores Fiduciais , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Cuidados Pré-Operatórios/instrumentação , Cuidados Pré-Operatórios/métodos , Radiografia Intervencionista , Estudos Retrospectivos , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Instrumentos Cirúrgicos , Cirurgia Torácica Vídeoassistida/instrumentação , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
7.
J Prosthodont ; 29(5): 409-414, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32237001

RESUMO

PURPOSE: Image registration of the optical intraoral scan to computed tomography image is essential for computer-guided implant surgery. The remaining teeth, which are considered to be congruent structures observed in the scan and radiographic images, are used to perform the image registration. The purpose of this study was to evaluate the effects of the distribution of matching fiducial points on the accuracy of the image registration. MATERIALS AND METHODS: A partially edentulous model with three anterior remaining teeth was prepared. Two mini dental implants were inserted in the posterior edentulous areas on both sides, and computed tomography and surface scan data were obtained. Three groups were set according to the distribution of the image matching points used: localized distribution, unilateral distribution, and bilateral distribution. Fifteen graduate students performed the registration process in each group using the same image matching method. The accuracy of image registration was evaluated by measuring the geometric discrepancies between the radiographic and registered scan images in the anterior, middle, and posterior regions. One-way and two-way analysis of variance with the Tukey HSD post hoc test were used for statistical analysis (α = 0.05) RESULTS: In general, the registration discrepancy was lowest in the bilateral distribution group, followed by the unilateral distribution and localized distribution groups (p< 0.001). In the regional analysis, the registration error tended to increase as the measurement region moved farther from the matching points. The distribution of the matching points and measurement regions had a statistical interaction in the accuracy of image registration. CONCLUSION: The accuracy of image registration of the surface scan to the computed tomography is affected by the matching point distribution that can be improved by placing artificial markers in the edentulous areas.


Assuntos
Implantes Dentários , Boca Edêntula , Cirurgia Assistida por Computador , Marcadores Fiduciais , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Tomografia Computadorizada por Raios X
8.
Health Phys ; 118(4): 438-442, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32126060

RESUMO

Radioactive seed localization procedures, using I seeds of typical activity 3.7 MBq and higher, are performed to localize nonpalpable lesions in the breast for surgical excision and pathology analysis. This study evaluated the use and dosimetry of I seeds of activity <3.7 MBq in radioactive seed localization procedures through retrospective health record review, Monte Carlo simulation, and experimental detection. An average seed strength at the time of specimen excision of 2.48 ± 0.629 MBq was used in 295 radioactive seed localization procedures at Gundersen Health System in La Crosse, Wisconsin, US. The average explanted seed activity served as a basis for Monte Carlo simulation of an I IsoAid Advantage seed embedded in soft tissue, which scored the dose deposited to soft tissue. Tabulated values of the dose to postsurgical residual tissue as a function of explanted tumor radius were shown and compared with previously published results. Use of seeds of activity from 1.44 to 3.7 MBq at the time of excision did not adversely affect seed detection and excision. The absorbed dose to residual tissue calculated using Monte Carlo was an average of 1.4 times larger than previously published results when scaled to identical seed strengths. This study demonstrates that seeds of activity <3.7 MBq can be used for radioactive seed localization procedures with no loss in efficacy and a benefit of reduced radiation dose to patients. This is important because the estimated radiation dose to residual tissue is approximately 1.4 times higher than previously indicated.


Assuntos
Mama/cirurgia , Radioisótopos do Iodo , Marcadores Fiduciais , Humanos , Método de Monte Carlo , Doses de Radiação , Fatores de Tempo
9.
Gen Thorac Cardiovasc Surg ; 68(5): 453-458, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32146580

RESUMO

Coronary artery bypass grafting (CABG) is one of the most common procedures in the United States as many Americans suffer from coronary heart disease and undergo CABG each year. While CABG has been performed for decades, questions remain regarding the benefits graft marker placement provides for patient therapy and outcomes. Markers at the proximal graft anastomosis aim to improve the efficiency and reduce the risks of subsequent, post-coronary artery bypass grafting coronary angiography by decreasing fluoroscopy time and contrast volume used. Graft markers have been shown to reduce fluoroscopy time and contrast volume, but concerns exist regarding their potentially negative impact on patient outcomes by increasing procedural time and possibly affecting graft patency. The relationship between graft markers and graft patency has not been studied in depth, and there is little evidence to show that graft patency is determined by graft marker placement. Because of the potential benefits to patients and the limited risks, it is important to continue studying graft marker usage and their effects on long-term outcomes.


Assuntos
Ponte de Artéria Coronária , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Marcadores Fiduciais , Grau de Desobstrução Vascular , Anastomose Cirúrgica , Meios de Contraste , Angiografia Coronária , Doença das Coronárias/cirurgia , Marcadores Fiduciais/estatística & dados numéricos , Fluoroscopia , Humanos , Duração da Cirurgia
10.
Cancer Radiother ; 24(2): 99-105, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32201058

RESUMO

PURPOSE: During radiotherapy (RT) for prostate cancer (PCa), interfraction and intrafraction movements can lead to decreased target dose coverage and unnecessary over-exposure of organs at risk. New image-guided RT techniques accuracy allows planning target volume (PTV) margins reduction. We aim to assess the feasibility of a kilovoltage intrafraction monitoring (KIM) to track the prostate during RT. METHODS AND MATERIALS: Between November 2017 and April 2018, 44 consecutive patients with PCa were included in an intrafraction prostate motion study using the Truebeam Auto Beam Hold® tracking system (Varian Medical Systems, United State) triggered by gold fiducials localization on kilovoltage (kV) imaging. A 5-mm PTV was considered. A significant gating event (SGE) was defined as the occurrence of an automatic beam interruption requiring patient repositioning following the detection of one fiducial outside a 5-mm target area around the marker during more than 45seconds. RESULTS: Six patients could not benefit from the KIM because of technical issues (loss of one fiducial marker=1, hip prosthesis=4, morbid obesity causing table movements=1). The mean rate of SGE per patient was 14±19%, and the fraction average delivery time was increased by 146±86seconds. For a plan of 39 fractions of 2Gy, the additional radiation dose increased by 0.13±0.09Gy. The mean rates of SGE were 2% and 18% (P=0.002) in patients with planned fraction<90 and>90seconds respectively, showing that duration of the session strongly interfered with prostate intrafraction movements. No other significant clinical and technical parameter was correlated with the occurrence of SGE. CONCLUSION: Automated intrafraction kV imaging can effectively perform autobeam holds due to intrafraction movement of the prostate in the large majority of patients. The additional radiation dose and delivery time are acceptable. This technique may be a cost-effective alternative to electromagnetic transponder guidance.


Assuntos
Movimentos dos Órgãos , Próstata/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Idoso , Idoso de 80 Anos ou mais , Fracionamento da Dose de Radiação , Estudos de Viabilidade , Marcadores Fiduciais , Ouro , Humanos , Masculino , Pessoa de Meia-Idade , Posicionamento do Paciente , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada/métodos , Glândulas Seminais , Fatores de Tempo , Incerteza
11.
Am Surg ; 86(2): 90-94, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32167041

RESUMO

We aimed to evaluate the surgical margin outcomes and re-excision rates in patients undergoing bracketed seed localization of biopsy-proven breast cancer detected on screening mammogram. After approval by our Institutional Review Board, we retrospectively identified patients who had undergone iodine-125 seed localized lumpectomy at our institution from January 2010 to June 2017 by one of two fellowship-trained breast surgeons. Of those patients, a subset of 25 patients were identified who had undergone bracketed seed localization, defined as two or more seeds used to delineate the radiographic borders of the area of concern. All patients had originally presented with calcifications identified on screening mammogram that were subsequently diagnosed as ductal carcinoma in situ and/or invasive ductal carcinoma by image-guided biopsy performed at our institution. Eight patients had one positive margin on final surgical pathology and required re-excision (32%). One patient was converted to mastectomy. Of the patients requiring re-excision, the average maximum linear extent of calcifications was 3.4 cm (SD 0.97), whereas it was 3.1 cm (SD 1.2) in patients with negative surgical margins (P = 0.5). Bracketing calcifications with radioactive seeds can potentially allow more patients to undergo breast conservation surgery.


Assuntos
Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/cirurgia , Carcinoma Intraductal não Infiltrante/cirurgia , Radioisótopos do Iodo/administração & dosagem , Mastectomia Segmentar/métodos , Tratamentos com Preservação do Órgão/métodos , Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Carcinoma Ductal de Mama/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Feminino , Marcadores Fiduciais , Humanos , Biópsia Guiada por Imagem , Mamografia , Margens de Excisão , Reoperação/estatística & dados numéricos , Estudos Retrospectivos
12.
Zhonghua Wai Ke Za Zhi ; 58(3): 165-169, 2020 Mar 01.
Artigo em Chinês | MEDLINE | ID: mdl-32187919

RESUMO

Image-guided percutaneous placement of breast tissue marker clip (breast marker) is mainly used for precisely marking and localizing breast cancer lesion and metastatic axillary lymph node. Until now, there is no clinical guideline in the field worldwide. This consensus established by Chinese Society of Breast Surgery, Chinese Surgical Society of Chinese Medical Association is based on our clinical practice and literature review, and particularly focuses on indications and contraindications, key placement procedures and evaluation methods, complications prevention and treatment, to provide guidance for the safe and standard clinical applications of breast marker.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Mama/diagnóstico por imagem , Marcadores Fiduciais , Linfonodos/diagnóstico por imagem , Axila , Consenso , Feminino , Humanos , Instrumentos Cirúrgicos
13.
World Neurosurg ; 137: 71-77, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32032794

RESUMO

BACKGROUND: This work attempts to simulate a robot-based autonomous targeted neurosurgical procedure such as biopsy on a vegetable specimen. The objective of the work is to validate the robot-based autonomous neuroregistration and neuronavigation for neurosurgery in terms of stereotactic navigation and target accuracy. CASE DESCRIPTION: A vegetable (carrot) fixed in a tray was used as a model. The tray was affixed with multiple markers. The robot autonomously registers the subject precisely and subsequently accesses the target. The navigation trajectory closely follows the path from the entry point to the target point, as specified in the medical image. The replication of procedures reveals that the target accuracies are within 1 mm. The results based on the case studies are presented. Intricate cases in terms of entry hole size, depth, and size of the target are considered for both phantom and vegetable trials. CONCLUSIONS: The results of the case studies show enhanced and consistent performance characteristics in terms of accuracy, precision, and repeatability with the added advantage of the economy of time. The case studies serve as validation for a high precision robot-assisted neuroregistration and neuronavigation task for neurosurgery and pave the way for further animal and human trials.


Assuntos
Neuronavegação/normas , Procedimentos Cirúrgicos Robóticos/normas , Técnicas Estereotáxicas/normas , Desenho de Equipamento , Marcadores Fiduciais , Humanos , Modelos Anatômicos , Neuronavegação/instrumentação , Neuronavegação/métodos , Imagens de Fantasmas , Procedimentos Cirúrgicos Robóticos/instrumentação , Procedimentos Cirúrgicos Robóticos/métodos , Técnicas Estereotáxicas/instrumentação , Instrumentos Cirúrgicos
14.
Phys Med Biol ; 65(8): 085005, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32053811

RESUMO

Fiducial markers are nowadays a common tool for patient positioning verification before radiotherapy treatment. These markers should be visible on x-ray projection imaging, produce low streak artifacts on CTs and induce small dose perturbations due to edge-scattering effects during the ion-beam therapy treatment. In this study, the latter effect was investigated and the perturbations created by the markers were evaluated with a new measurement method using a tracker system composed of six CMOS pixel sensors. The present method enables the determination of the particle trajectory before and after the target. The experiments have been conducted at the Marburg Ion Beam Therapy Center with carbon ion beams and the measurement concept was validated by comparison with radiochromic films. This work shows that the new method is very efficient and precise to measure the perturbations due to fiducial markers with a tracker system. Three dimensional fluence distributions of all particle trajectories were reconstructed and the maximum cold spots due to the markers and their position along the beam axis were quantified. In this study, four small commercial markers with different geometries and materials (gold and carbon-coated ZrO2) were evaluated. The gold markers showed stronger perturbations than the lower density ones. However, it is important to consider that low density and low atomic number fiducial markers are not always visible on x-ray projections.


Assuntos
Marcadores Fiduciais , Radioterapia com Íons Pesados/normas , Posicionamento do Paciente , Espalhamento de Radiação , Artefatos , Ouro , Humanos , Planejamento da Radioterapia Assistida por Computador
15.
Can Assoc Radiol J ; 71(1): 58-62, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32062988

RESUMO

OBJECTIVES: To assess the benefits associated with radioactive seed localization (RSL) in comparison to conventional wire localization (WL) for nonpalpable breast lesions. METHODS: Radioactive seed localization was initiated at our institution in July 2013. Retrospective review of all WL performed between June 2012 and July 2013 (2013) and all RSL performed during June 2015 and July 2016 (2016). Patients who received neoadjuvant therapy or did not undergo their planned surgeries and WL performed in 2016 were excluded. The following data were collected: final pathology, resection margins for malignant lesions, time to surgery, seed migration, and number of localized lumpectomies performed by each surgeon. RESULTS: A total of 292 WL procedures (288 women) in 2013 and 194 RSL procedures (186 women) in 2016 were eligible for the study. All WLs were inserted the day of surgery. Mean time from RSL insertion to surgery was 4.0 ± 2.8 days (range: 1-17 days). There was no difference in specimen size for malignant lesions (6.8 ± 2.8 cm for WL and 6.9 ± 2.9 cm for RSL; P = .5). Specimen radiographs were obtained in 233 (80%) of 292 WL compared to 194 (100%) of 194 RSL (P < .001). For malignant lesions, positive margins were present in 34 (17.2%) of 198 with WL compared to 15 (10.3%) of 146 with RSL (P < .001). Close margins (≤1 mm) were present in 31 (15.6%) of 198 with WL compared to 1 (0.6%) of 146 with RSL (P < .001). The seed fell out of the specimen during surgery in 6 (3.1%) of 194. No seed loss was recorded. The surgeons (n = 4) who transitioned to RSL increased the number of surgeries per month from a mean of 4.4 ± 2.6 in 2013 to 6.9 ± 3.5 in 2016, equivalent to a 41% increase (P = .003). CONCLUSIONS: The use of RSL, as compared to conventional WL, resulted in a reduction in the number of pathologically involved surgical margins and was associated with an increased number of surgeries. Furthermore, RSL can be performed up to 14 days prior to surgery, which may improve scheduling flexibility in the radiology department.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Marcadores Fiduciais , Adulto , Idoso , Feminino , Humanos , Radioisótopos do Iodo , Mamografia , Mastectomia Segmentar , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Br J Radiol ; 93(1109): 20190571, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32017601

RESUMO

OBJECTIVE: (1) To evaluate the value of CT-guided microcoil implantation for localizing pulmonary ground-glass nodules (GGNs) before video-assisted thoracoscopic surgery (VATS). (2) To evaluate the feasibility, safety and accuracy of cephalic-caudal oblique approach for lesions difficult to access on axial images owing to overlying bony structures, large vessels or interlober fissures. METHODS: From June 2016 to March 2019, all patients with GGNs resected by VATS after marking using CT-guided microcoil implantation in China-Japan friendship hospital were enrolled and clinical and imaging data were retrospectively analyzed. According to the microcoil marked path, the GGNs were divided into cephalic-caudal oblique group (oblique group) and non-oblique group. The success rate of marking, the time required for marking and the incidence of complications between the two groups were compared. RESULTS: 258 GGNs from 215 consecutive patients were included in this study. The diameter of GGNs was 1.22 ± 0.50 cm, and the shortest distance from GGNs to the pleura was 1.56 ± 1.09 cm. All 258 GGNs were successfully resected by VATS under the guidance of implanted microcoils, and no case was converted to thoracotomy. During CT-guided microcoil implantation, cephalic- caudal oblique approach was taken in 56 GGNs (oblique group) to avoid bone, interlobar fissure and blood vessels. The time required for marking was significantly longer for oblique group compared with non-oblique group (16.6 ± 2.4 vs. 13.1 ± 1.9 min, p<0.01). No significant differences in the success rate of marking (94.6% vs 91.6%), the incidence of pneumothorax (19.6% vs 17.8%), the bleeding rate (10.7% vs 8.9%), and the hemoptysis rate (1.8% vs 1.5%) were observed between the two groups. CONCLUSION: CT-guided microcoil implantation can effectively guide VATS to resect GGNs. For GGNs difficult to access on axial images, CT-guided cephalic-caudal oblique approach is feasible, safe, and accurate. ADVANCES IN KNOWLEDGE: CT-guided microcoil implantation can effectively guide VATS to resect GGNs. The marked path with cephalic-caudal obliquity can effectively avoid bone, interlobar fissure and blood vessels, successfully mark GGNs difficult to access on axial images, while keeping the distance from the pleura to the lesion on the marked path as short as possible at the same time.


Assuntos
Neoplasias Pulmonares/cirurgia , Nódulos Pulmonares Múltiplos/cirurgia , Cirurgia Torácica Vídeoassistida/métodos , Estudos de Viabilidade , Feminino , Marcadores Fiduciais , Humanos , Masculino , Pessoa de Meia-Idade , Implantação de Prótese , Radiografia Intervencionista , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
17.
J Sports Sci ; 38(5): 518-527, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31900052

RESUMO

The purpose of this study was to investigate the effects of slope on three-dimensional running kinematics at high speed. Thirteen male sprinters ran at high speed (7.5 m/s) on a motorised treadmill in each a level and a 5.0% slope condition. Three-dimensional motion analysis was conducted to compare centre of mass (CoM) energetics, pelvis segment and lower limb joints kinematics. We found that contact time was not affected by the slope, whereas flight time and step length were significantly shorter in uphill compared to level running. Uphill running reduced negative CoM work and increased positive CoM work compared to level running. Ankle, knee and hip joints were more flexed at initial ground contact, but only the knee was more extended at the end of stance in uphill compared to level running. Additionally, the hip joint was more abducted, and the free leg side of the pelvis was more elevated at the end of stance in uphill running. Our results demonstrate that joint motion must be developed from a more flexed/adducted position at initial contact through a greater range of motion compared to level running in order to meet the greater positive CoM work requirements in uphill running at high speed.


Assuntos
Articulação do Tornozelo/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Corrida/fisiologia , Fenômenos Biomecânicos/fisiologia , Teste de Esforço , Marcadores Fiduciais , Marcha , Humanos , Imageamento Tridimensional , Masculino , Movimento/fisiologia , Amplitude de Movimento Articular/fisiologia , Adulto Jovem
18.
PLoS One ; 15(1): e0226648, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31995610

RESUMO

In clinical gait analysis, measurement errors impede the reliability and repeatability of the measurements. This extrinsic variability can potentially mislead the clinical interpretation of the analysis and should thus be minimised. Skin marker misplacement has been identified as the largest source of extrinsic variability between measurements. The goal of this study was to test whether the fusion of motion capture and 3D medical imaging could reduce extrinsic variability due to skin marker misplacement. The fusion method consists in using anatomical landmarks identified with 3D medical imaging to correct marker misplacements. To assess the reduction of variability accountable to the fusion method, skin marker misplacements were voluntarily introduced in the measurement of the pelvis and hip kinematics during gait for two patients scheduled for unilateral hip arthroplasty and two patients that underwent unilateral hip arthroplasty. The root mean square deviation was reduced by -78 ± 15% and the range of variability by -80 ± 16% for the pelvis and hip kinematics in average. These results showed that the fusion method could significantly reduce the extrinsic variability due to skin marker misplacement and thus increase the reliability and repeatability of motion capture measurements. However, the identification of anatomical landmarks via medical imaging is a new source of extrinsic variability that should be assessed before considering the fusion method for clinical applications.


Assuntos
Marcadores Fiduciais , Marcha/fisiologia , Articulação do Quadril/fisiologia , Imageamento Tridimensional/métodos , Movimento , Pelve/fisiologia , Pele/metabolismo , Idoso , Artroplastia de Quadril/métodos , Fenômenos Biomecânicos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Modelos Biológicos , Amplitude de Movimento Articular
19.
PLoS One ; 15(1): e0227286, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31910228

RESUMO

In order to unravel rapid mechano-chemical feedback mechanisms in sprouting angiogenesis, we combine selective plane illumination microscopy (SPIM) and tailored image registration algorithms - further referred to as SPIM-based displacement microscopy - with an in vitro model of angiogenesis. SPIM successfully tackles the problem of imaging large volumes while upholding the spatial resolution required for the analysis of matrix displacements at a subcellular level. Applied to in vitro angiogenic sprouts, this unique methodological combination relates subcellular activity - minute to second time scale growing and retracting of protrusions - of a multicellular systems to the surrounding matrix deformations with an exceptional temporal resolution of 1 minute for a stack with multiple sprouts simultaneously or every 4 seconds for a single sprout, which is 20 times faster than with a conventional confocal setup. Our study reveals collective but non-synchronised, non-continuous activity of adjacent sprouting cells along with correlations between matrix deformations and protrusion dynamics.


Assuntos
Imageamento Tridimensional/métodos , Microscopia Intravital/métodos , Neovascularização Fisiológica/fisiologia , Imagem com Lapso de Tempo , Algoritmos , Técnicas de Cultura de Células/métodos , Colágeno Tipo I , Marcadores Fiduciais , Células Endoteliais da Veia Umbilical Humana , Humanos , Hidrogéis , Microscopia de Fluorescência/métodos , Microesferas
20.
Int J Radiat Oncol Biol Phys ; 106(3): 630-638, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31759076

RESUMO

PURPOSE: Intensity modulated proton therapy (IMPT) of locally advanced prostate cancer can spare the bowel considerably compared with modern photon therapy, but simultaneous treatment of the prostate (p), seminal vesicles (sv), and lymph nodes is challenging owing to day-to-day organ motion and range uncertainties. Our purpose was, therefore, to generate a plan library for use in adaptive IMPT to mitigate these uncertainties. METHODS AND MATERIALS: We retrospectively included 27 patients with a series of computed tomography scans throughout their treatment representing day-to-day variation. In 18 of the patients, target motion was analyzed using rigid shifts of prostate gold markers relative to bony anatomy. A plan library with different p and sv planning target volume (p/sv-PTV) positions was defined from the distribution and direction of these shifts. Delivery of IMPT using plan selection from the library was simulated for image guidance on bony anatomy, in the remaining patients and compared with nonadaptive IMPT. RESULTS: The plan library consisted of 3 small margin p/sv-PTVs: (1) p/sv-PTV shifted 1.5 systematic error (Σ) of the population mean in the anterior and cranial directions, (2) p/sv-PTV shifted 1.5Σ in the posterior and caudal directions, and (3) p/sv-PTV in the planning position. The conventional p/sv-PTV was also available for backup. Plan selection compared with nonadaptive IMPT resulted in a reduction of the rectum volume receiving 60 Gy relative biological effect (RBE) (V60GyRBE) from on average 12 mL to 9 mL. For the bladder the average V45GyRBE was reduced from 36% to 30%. Large and small bowel doses were also reduced, whereas target coverage was comparable or improved compared with nonadaptive IMPT. CONCLUSIONS: Plan selection based on a population model of rigid target motion was feasible for all patients. Compared with conventional IMPT, plan selection resulted in significant dosimetric sparing of rectum and bladder without compromising target coverage.


Assuntos
Movimentos dos Órgãos , Neoplasias da Próstata/radioterapia , Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada/métodos , Pontos de Referência Anatômicos/diagnóstico por imagem , Marcadores Fiduciais , Ouro , Humanos , Bibliotecas Digitais , Linfonodos/diagnóstico por imagem , Irradiação Linfática/métodos , Masculino , Tratamentos com Preservação do Órgão/métodos , Órgãos em Risco/diagnóstico por imagem , Próstata/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Guiada por Imagem/métodos , Reto/diagnóstico por imagem , Estudos Retrospectivos , Glândulas Seminais/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Incerteza , Bexiga Urinária/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA