Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
1.
Brain Stimul ; 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34610480
2.
Artigo em Inglês | MEDLINE | ID: mdl-34545610

RESUMO

We investigated the impact of new systemic therapies approved in Canada for colorectal cancer on the frequency, intensity and duration of oncology clinic and infusion visits over five treatment phases from diagnosis (P1, P3) to treatment (P2, P4) of primary and metastatic disease, respectively, and during the last 6 months of life (P5). In total, 15,157 adult patients with newly diagnosed colorectal cancer and referred between 2000 and 2012 to any cancer clinic in British Columbia, Canada, were included. Frequency, intensity and duration of medical oncology clinic visits (CVs), oncology infusions (OIs) and oncology prescriptions (OPs) were measured by treatment phase. Mean, total and adjusted total duration for CVs increased for P1-5. CVs increased in P1-5, and in P1-4 when adjusted by treatment length. Adjusted and unadjusted OIs decreased in P1 coinciding with the introduction of an oral treatment option, but increased in P2-5. Mean OI duration increased in P1-5, while total and adjusted total decreased in P1 and increased in P2-5. OPs increased in P2-4, but were unchanged in P1 and P5. Multi-fold increases in resources and time required per patient were also observed, which have significant implications for demand projections in cancer care planning and delivery. In conclusion, patients required more visits in almost all treatment phases, visits on average took longer and patients were in treatment for longer periods of time.

3.
Can J Surg ; 64(5): E467-E472, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34467751

RESUMO

Summary: General surgery remains a broad and unclearly defined specialty in small and medium-sized communities, where general surgeons perform more subspecialty and non-core procedures than their urban counterparts. It is unclear what specific procedures are being performed or whether today's residents are being trained to meet community needs. We surveyed the members of the British Columbia (BC) Surgical Society and found that only 3% of BC's surgeons believe today's graduates are "definitely prepared" for a broad-based community practice. We also identified several non-core procedures performed more frequently by general surgeons in small and medium-sized communities. General surgery residency is narrowing its focus despite the fact that community general surgeons are maintaining a broad-based practice. To meet the needs of smaller communities, residency programs need to address the discrepancies that exist between the emphasis within the current training structure and the practice of our community surgeons.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34467443

RESUMO

PURPOSE: Immediate breast reconstruction (IBR) following mastectomy remains controversial for locally advanced breast cancer over concerns regarding recurrence and complications which may delay adjuvant therapies. This study aimed to compare the oncologic outcomes and surgical safety of IBR following mastectomy with mastectomy alone (MA) for locally advanced breast cancer. METHODS: All patients treated at the Providence Breast Center between 2012 and 2017 for biopsy-proven locally advanced breast cancer, AJCC (8th edition) clinical stages (IIB-IIIC), were included. Primary outcomes were overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS). Secondary outcomes included recurrence rate, adjuvant therapy use, and reoperation. RESULTS: 267 patients (112 IBR, 155 MA) were included. On average, IBR patients were younger (48.82 years vs 61.42 years, P < 0.001). Median study follow-up was 50.7 months. OS was higher among IBR patients (86.6% vs 73.5%, P < 0.05). However, no significant differences were found in DSS (87.5% vs 84.5%, P = 0.34), DFS (79.5% vs 78.7%, P = 0.55), local recurrence (0% vs 1.9%, P = 0.194), adjuvant therapy use (95.5% vs 91.6%, P = 0.155), or reoperation (1.8% vs 1.3%, P = 0.559). CONCLUSION: IBR is a safe option for patients with locally advanced breast cancer and does not negatively impact survival, cancer recurrence rates, and use of adjuvant therapy.

6.
Brain Stimul ; 14(5): 1095-1105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34332155

RESUMO

INTRODUCTION: Theta burst pattern repetitive transcranial magnetic stimulation (TBS) is increasingly applied to treat depression. TBS's brevity is well-suited to application in accelerated schedules. Sizeable trials of accelerated TBS are lacking; and optimal TBS parameters such as stimulation intensity are not established. METHODS: We conducted a three arm, single blind, randomised, controlled, multi-site trial comparing accelerated bilateral TBS applied at 80 % or 120 % of the resting motor threshold and left unilateral 10 Hz rTMS. 300 patients with treatment-resistant depression (TRD) were recruited. TBS arms applied 20 bilateral prefrontal TBS sessions over 10 days, while the rTMS arm applied 20 daily sessions of 10 Hz rTMS to the left prefrontal cortex over 4 weeks. Primary outcome was depression treatment response at week 4. RESULTS: The overall treatment response rate was 43.7 % and the remission rate was 28.2 %. There were no significant differences for response (p = 0.180) or remission (p = 0.316) across the three groups. Response rates between accelerated bilateral TBS applied at sub- and supra-threshold intensities were not significantly different (p = 0.319). Linear mixed model analysis showed a significant effect of time (p < 0.01), but not rTMS type (p = 0.680). CONCLUSION: This is the largest accelerated bilateral TBS study to date and provides evidence that it is effective and safe in treating TRD. The accelerated application of TBS was not associated with more rapid antidepressant effects. Bilateral sequential TBS did not have superior antidepressant effect to unilateral 10 Hz rTMS. There was no significant difference in antidepressant efficacy between sub- and supra-threshold accelerated bilateral TBS.

7.
Urol Oncol ; 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34247909

RESUMO

BACKGROUND: While multiparametric MRI (mpMRI) has high sensitivity for detection of clinically significant prostate cancer (CSC), false positives and negatives remain common. Calculators that combine mpMRI with clinical variables can improve cancer risk assessment, while providing more accurate predictions for individual patients. We sought to create and externally validate nomograms incorporating Prostate Imaging Reporting and Data System (PIRADS) scores and clinical data to predict the presence of CSC in men of all biopsy backgrounds. METHODS: Data from 2125 men undergoing mpMRI and MR fusion biopsy from 2014 to 2018 at Stanford, Yale, and UAB were prospectively collected. Clinical data included age, race, PSA, biopsy status, PIRADS scores, and prostate volume. A nomogram predicting detection of CSC on targeted or systematic biopsy was created. RESULTS: Biopsy history, Prostate Specific Antigen (PSA) density, PIRADS score of 4 or 5, Caucasian race, and age were significant independent predictors. Our nomogram-the Stanford Prostate Cancer Calculator (SPCC)-combined these factors in a logistic regression to provide stronger predictive accuracy than PSA density or PIRADS alone. Validation of the SPCC using data from Yale and UAB yielded robust AUC values. CONCLUSIONS: The SPCC combines pre-biopsy mpMRI with clinical data to more accurately predict the probability of CSC in men of all biopsy backgrounds. The SPCC demonstrates strong external generalizability with successful validation in two separate institutions. The calculator is available as a free web-based tool that can direct real-time clinical decision-making.

8.
Am J Surg ; 221(6): 1172-1176, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33795126

RESUMO

BACKGROUND: Contralateral prophylactic mastectomy (CPM) is not recommended for average-risk women with breast cancer due to lack of evidence for survival benefit, yet recent studies demonstrate increasing CPM rates. METHODS: We identified patients with breast cancer treated with unilateral mastectomy (UM) with or without CPM. Rates of malignancy in CPM specimens and factors in CPM rates were assessed. RESULTS: From 2013 to 2017, 1353 patients had UM and 355 had CPM. Our institution's occult malignancy detection rate was 5.04%. CPM rates decreased from 31.6% to 17.3% (p < 0.001) over 5 years. Compared to patients receiving UM only, patients receiving CPMs had significantly higher reconstruction rates (p < 0.001), which did not significantly change over time (p = 0.551) and tended to be younger (p < 0.001). CONCLUSIONS: Patients having UM have low risk of contralateral malignancy. CPM is associated with younger age and breast reconstruction, suggesting factors to identify for patient and provider education.


Assuntos
Neoplasias da Mama/cirurgia , Mastectomia Profilática/estatística & dados numéricos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Canadá , Feminino , Humanos , Mamoplastia/estatística & dados numéricos , Mastectomia/estatística & dados numéricos , Pessoa de Meia-Idade , Fatores de Risco
9.
Am J Surg ; 221(6): 1167-1171, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33810833

RESUMO

BACKGROUND: Surgical decisions for ductal carcinoma in situ (DCIS) are based on lesion sizes. This study aims to determine the accuracy of pre-operative imaging in estimating the size of DCIS. METHODS: This was a retrospective review of clinicopathologic data of patients treated for DCIS with breast conserving surgery (BCS) between 2012 and 2018. Mammographic and sonographic lesion sizes were compared with final pathology sizes. RESULTS: For the 152 lesions visible on mammography, mean size on imaging was significantly smaller when compared to final pathology (2.3 vs. 3.6 cm, p < 0.001). The mean difference of 1.3 cm was a significant underestimation with a correlation coefficient of 0.367 (p < 0.001). For 48 sonographically visible lesions, the radiologic size was significantly smaller than pathologic size (1.7 vs. 4.1 cm, p < 0.001), but the degree of underestimation was not significantly correlated (p = 0.379). CONCLUSION: DCIS size was significantly underestimated by imaging. This must be taken into consideration during surgical planning.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Carcinoma Intraductal não Infiltrante/diagnóstico por imagem , Mamografia , Ultrassonografia Mamária , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Mama/diagnóstico por imagem , Mama/patologia , Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
J Urol ; 206(3): 604-612, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33878887

RESUMO

PURPOSE: Targeted biopsy improves prostate cancer diagnosis. Accurate prostate segmentation on magnetic resonance imaging (MRI) is critical for accurate biopsy. Manual gland segmentation is tedious and time-consuming. We sought to develop a deep learning model to rapidly and accurately segment the prostate on MRI and to implement it as part of routine magnetic resonance-ultrasound fusion biopsy in the clinic. MATERIALS AND METHODS: A total of 905 subjects underwent multiparametric MRI at 29 institutions, followed by magnetic resonance-ultrasound fusion biopsy at 1 institution. A urologic oncology expert segmented the prostate on axial T2-weighted MRI scans. We trained a deep learning model, ProGNet, on 805 cases. We retrospectively tested ProGNet on 100 independent internal and 56 external cases. We prospectively implemented ProGNet as part of the fusion biopsy procedure for 11 patients. We compared ProGNet performance to 2 deep learning networks (U-Net and holistically-nested edge detector) and radiology technicians. The Dice similarity coefficient (DSC) was used to measure overlap with expert segmentations. DSCs were compared using paired t-tests. RESULTS: ProGNet (DSC=0.92) outperformed U-Net (DSC=0.85, p <0.0001), holistically-nested edge detector (DSC=0.80, p <0.0001), and radiology technicians (DSC=0.89, p <0.0001) in the retrospective internal test set. In the prospective cohort, ProGNet (DSC=0.93) outperformed radiology technicians (DSC=0.90, p <0.0001). ProGNet took just 35 seconds per case (vs 10 minutes for radiology technicians) to yield a clinically utilizable segmentation file. CONCLUSIONS: This is the first study to employ a deep learning model for prostate gland segmentation for targeted biopsy in routine urological clinical practice, while reporting results and releasing the code online. Prospective and retrospective evaluations revealed increased speed and accuracy.


Assuntos
Aprendizado Profundo , Processamento de Imagem Assistida por Computador/métodos , Próstata/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico , Conjuntos de Dados como Assunto , Estudos de Viabilidade , Humanos , Biópsia Guiada por Imagem/métodos , Imagem por Ressonância Magnética Intervencionista , Masculino , Imagem Multimodal/métodos , Imageamento por Ressonância Magnética Multiparamétrica , Estudo de Prova de Conceito , Estudos Prospectivos , Próstata/patologia , Neoplasias da Próstata/patologia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Software , Fatores de Tempo , Ultrassonografia de Intervenção/métodos
11.
Med Phys ; 48(6): 2960-2972, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33760269

RESUMO

PURPOSE: While multi-parametric magnetic resonance imaging (MRI) shows great promise in assisting with prostate cancer diagnosis and localization, subtle differences in appearance between cancer and normal tissue lead to many false positive and false negative interpretations by radiologists. We sought to automatically detect aggressive cancer (Gleason pattern ≥ 4) and indolent cancer (Gleason pattern 3) on a per-pixel basis on MRI to facilitate the targeting of aggressive cancer during biopsy. METHODS: We created the Stanford Prostate Cancer Network (SPCNet), a convolutional neural network model, trained to distinguish between aggressive cancer, indolent cancer, and normal tissue on MRI. Ground truth cancer labels were obtained by registering MRI with whole-mount digital histopathology images from patients who underwent radical prostatectomy. Before registration, these histopathology images were automatically annotated to show Gleason patterns on a per-pixel basis. The model was trained on data from 78 patients who underwent radical prostatectomy and 24 patients without prostate cancer. The model was evaluated on a pixel and lesion level in 322 patients, including six patients with normal MRI and no cancer, 23 patients who underwent radical prostatectomy, and 293 patients who underwent biopsy. Moreover, we assessed the ability of our model to detect clinically significant cancer (lesions with an aggressive component) and compared it to the performance of radiologists. RESULTS: Our model detected clinically significant lesions with an area under the receiver operator characteristics curve of 0.75 for radical prostatectomy patients and 0.80 for biopsy patients. Moreover, the model detected up to 18% of lesions missed by radiologists, and overall had a sensitivity and specificity that approached that of radiologists in detecting clinically significant cancer. CONCLUSIONS: Our SPCNet model accurately detected aggressive prostate cancer. Its performance approached that of radiologists, and it helped identify lesions otherwise missed by radiologists. Our model has the potential to assist physicians in specifically targeting the aggressive component of prostate cancers during biopsy or focal treatment.


Assuntos
Neoplasias da Próstata , Humanos , Imageamento por Ressonância Magnética , Masculino , Gradação de Tumores , Prostatectomia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia
12.
Am J Surg ; 221(6): 1228-1232, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33766412

RESUMO

BACKGROUND: Enhanced recovery pathways aim to reduce postoperative opioid use and opioid-related complications. These pathways often include epidural analgesia (EA). This study examines postoperative opioid use after elective laparotomy with and without EA. METHODS: Retrospective chart review of elective laparotomies performed by General Surgery at a tertiary academic center during 2017 was completed. Primary outcome was postoperative opioid usage. Secondary outcomes were time to mobilization, duration of urinary catheterization and postoperative ileus. RESULTS: Among 236 patients, 213 (90%) received EA. There was no significant difference in mean total oral morphine equivalent (OME) usage between EA and non-EA groups. Mean OME use on postoperative day three was higher in the EA group (38.0 vs 22.4 mg, p = 0.02). On multivariate analysis, preoperative opioid use was associated with increased postoperative OME consumption (regression coefficient 147.5, p < 0.001). CONCLUSIONS: In this cohort, epidural analgesia did not reduce postoperative opioid consumption.


Assuntos
Analgesia Epidural , Analgésicos Opioides/uso terapêutico , Procedimentos Cirúrgicos Eletivos , Laparotomia , Dor Pós-Operatória/prevenção & controle , Analgesia Epidural/métodos , Colúmbia Britânica , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Hospitais Gerais/estatística & dados numéricos , Humanos , Laparotomia/efeitos adversos , Laparotomia/métodos , Masculino , Pessoa de Meia-Idade , Morfina/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Estudos Retrospectivos
13.
Am J Surg ; 221(6): 1177-1181, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33773749

RESUMO

BACKGROUND: We assessed the cancer upstage rate of Radial Scars (RS), and Complex Sclerosing Lesions (CSL), and risk-stratified lesions based on radiological and pathological features. METHODS: Characteristics of RS/CSL treated from 2013 to 2018 were examined for features associated with cancer. RESULTS: 78 RS/CSL were found on core needle biopsy (CNB) and surgically excised. 9 (11.5%) lesions were upstaged. Upstaged patients were older (66 vs 51, p = 0.033). More upstaged lesions were accompanied by a mass on both mammography (87.5% vs. 30.0%, p = 0.005) and ultrasound (100.0% vs. 62.8%, p = 0.043). 20.5% of lesions biopsied under ultrasound guidance with small needles (14-18G) were upstaged, but no lesions biopsied under stereotactic guidance with large needles (9-12 G) with vacuum assistance were upstaged (p = 0.009). CONCLUSIONS: Excision of RS/CSL seen on CNB is warranted, especially if the patient is older, the CNB is performed under ultrasound guidance with small needles, or if a mass is present on imaging.


Assuntos
Biópsia com Agulha de Grande Calibre , Doenças Mamárias/diagnóstico , Neoplasias da Mama/diagnóstico , Cicatriz/diagnóstico , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças Mamárias/diagnóstico por imagem , Doenças Mamárias/epidemiologia , Doenças Mamárias/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Cicatriz/diagnóstico por imagem , Cicatriz/epidemiologia , Cicatriz/patologia , Feminino , Humanos , Mamografia , Pessoa de Meia-Idade , Esclerose , Adulto Jovem
14.
Cancer Discov ; 11(7): 1754-1773, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33608386

RESUMO

Cancer genotyping has identified a large number of putative tumor suppressor genes. Carcinogenesis is a multistep process, but the importance and specific roles of many of these genes during tumor initiation, growth, and progression remain unknown. Here we use a multiplexed mouse model of oncogenic KRAS-driven lung cancer to quantify the impact of 48 known and putative tumor suppressor genes on diverse aspects of carcinogenesis at an unprecedented scale and resolution. We uncover many previously understudied functional tumor suppressors that constrain cancer in vivo. Inactivation of some genes substantially increased growth, whereas the inactivation of others increases tumor initiation and/or the emergence of exceptionally large tumors. These functional in vivo analyses revealed an unexpectedly complex landscape of tumor suppression that has implications for understanding cancer evolution, interpreting clinical cancer genome sequencing data, and directing approaches to limit tumor initiation and progression. SIGNIFICANCE: Our high-throughput and high-resolution analysis of tumor suppression uncovered novel genetic determinants of oncogenic KRAS-driven lung cancer initiation, overall growth, and exceptional growth. This taxonomy is consistent with changing constraints during the life history of cancer and highlights the value of quantitative in vivo genetic analyses in autochthonous cancer models.This article is highlighted in the In This Issue feature, p. 1601.

15.
Am J Surg ; 221(4): 813-818, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32334802

RESUMO

INTRODUCTION: Pancreatic cystic neoplasms (PCNs) are being incidentally detected at an increased rate due to increased CT and MRI usage. EUS is an emerging tool that can differentiate between benign and malignant features of pancreatic cysts. We hoped to identify the specific cross-sectional imaging findings and patient characteristics that warrant EUS referral. METHODS: We conducted a retrospective case-control chart review, evaluating patients, who were diagnosed with pancreatic cysts and underwent EUS between January 1, 2010 and December 31, 2017. RESULTS: EUS was found to change management when CT imaging found cyst size > 4 cm (OR = 4.07, p < 0.01), cyst size > 3 cm (OR = 3.79, p < 0.001) and associated solid component to the cyst (OR = 5.95, p < 0.01). Additionally, patient characteristics, including age less than 50 years, male sex and 10-pack year smoking history were significantly associated with EUS change in management. DISCUSSION: Our findings suggest that EUS referral should be coordinated based on the findings of specific HRFs, with support from high risk patient characteristics, rather than the accumulation of multiple HRFs, as suggested by existing guidelines.


Assuntos
Endossonografia , Cisto Pancreático/diagnóstico por imagem , Cisto Pancreático/terapia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/terapia , Fatores Etários , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores Sexuais , Fumar
16.
Australas Psychiatry ; 29(1): 26-30, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33043677

RESUMO

OBJECTIVE: To examine psychological distress in healthcare workers (HCWs) during the COVID-19 pandemic in April-May 2020. METHODS: A cross-sectional survey examining demographic, employment and mental health characteristics of HCWs in a large metropolitan hospital in Australia. RESULTS: HCWs showed significant symptoms of moderate-severe level depression (21%), anxiety (20%) and posttraumatic stress disorder (PTSD; 29%), associated with burnout, prior psychiatric history, profession and resilience. CONCLUSION: Despite low levels of COVID contact, moderate to high levels of psychological distress were reported. Continued monitoring and support for HCWs' mental well-being is warranted as the COVID-19 pandemic develops.


Assuntos
Transtornos de Ansiedade/epidemiologia , Esgotamento Profissional/epidemiologia , COVID-19 , Transtorno Depressivo/epidemiologia , Hospitais Urbanos/estatística & dados numéricos , Recursos Humanos em Hospital/estatística & dados numéricos , Angústia Psicológica , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Adulto , Austrália/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
HPB (Oxford) ; 23(8): 1185-1195, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33334675

RESUMO

BACKGROUND: Conflicting data persists for use of wound protectors in pancreatoduodenectomy (PD) to prevent surgical site infection (SSI). We aimed to examine, at a multi-institutional level, the effect of wound protectors on superficial or deep SSI following elective open PD. METHODS: The American College of Surgeons National Surgical Quality Improvement Program pancreatectomy procedure targeted participant use file was queried from 2016 to 2018. Planned open PD procedures were extracted. Univariable, multivariable, and propensity score matched analyses were conducted. RESULTS: 11,562 patients undergoing PD were evaluated, 27% of which used wound protectors. Wound protectors decreased superficial or deep SSI risk in all patients (5.7% vs. 9.5%, P < 0.001), patients who have (6.6% vs. 12.2%, P < 0.001) and who did not have (4.6% vs. 6.5%, P = 0.011) a biliary stent. Propensity score matched analysis confirms such results (OR = 0.56, 95% CI: 0.46-0.69, P < 0.001 overall, OR = 0.66, 95% CI: 0.46-0.95, P = 0.03 without biliary stent, OR = 0.57, 95% CI: 0.44-0.73, P < 0.001 with biliary stent). CONCLUSIONS: Wound protectors reduce risk of superficial or deep SSI in patients undergoing PD, yet only a quarter of PD were associated with their use. This protective effect is seen whether patients have or have not had preoperative biliary stenting.

18.
J Neurosurg Pediatr ; : 1-8, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33260138

RESUMO

OBJECTIVE: Imaging evaluation of the cerebral ventricles is important for clinical decision-making in pediatric hydrocephalus. Although quantitative measurements of ventricular size, over time, can facilitate objective comparison, automated tools for calculating ventricular volume are not structured for clinical use. The authors aimed to develop a fully automated deep learning (DL) model for pediatric cerebral ventricle segmentation and volume calculation for widespread clinical implementation across multiple hospitals. METHODS: The study cohort consisted of 200 children with obstructive hydrocephalus from four pediatric hospitals, along with 199 controls. Manual ventricle segmentation and volume calculation values served as "ground truth" data. An encoder-decoder convolutional neural network architecture, in which T2-weighted MR images were used as input, automatically delineated the ventricles and output volumetric measurements. On a held-out test set, segmentation accuracy was assessed using the Dice similarity coefficient (0 to 1) and volume calculation was assessed using linear regression. Model generalizability was evaluated on an external MRI data set from a fifth hospital. The DL model performance was compared against FreeSurfer research segmentation software. RESULTS: Model segmentation performed with an overall Dice score of 0.901 (0.946 in hydrocephalus, 0.856 in controls). The model generalized to external MR images from a fifth pediatric hospital with a Dice score of 0.926. The model was more accurate than FreeSurfer, with faster operating times (1.48 seconds per scan). CONCLUSIONS: The authors present a DL model for automatic ventricle segmentation and volume calculation that is more accurate and rapid than currently available methods. With near-immediate volumetric output and reliable performance across institutional scanner types, this model can be adapted to the real-time clinical evaluation of hydrocephalus and improve clinician workflow.

19.
Front Surg ; 7: 517375, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33195383

RESUMO

Introduction: Surgical resection of brain tumors is often limited by adjacent critical structures such as blood vessels. Current intraoperative navigations systems are limited; most are based on two-dimensional (2D) guidance systems that require manual segmentation of any regions of interest (ROI; eloquent structures to avoid or tumor to resect). They additionally require time- and labor-intensive processing for any reconstruction steps. We aimed to develop a deep learning model for real-time fully automated segmentation of the intracranial vessels on preoperative non-angiogram imaging sequences. Methods: We identified 48 pediatric patients (10-months to 22-years old) with high resolution (0.5-1 mm axial thickness) isovolumetric, pre-operative T2 magnetic resonance images (MRIs). Twenty-eight patients had anatomically normal brains, and 20 patients had tumors or other lesions near the skull base. Manually segmented intracranial vessels (internal carotid, middle cerebral, anterior cerebral, posterior cerebral, and basilar arteries) served as ground truth labels. Patients were divided into 80/5/15% training/validation/testing sets. A modified 2-D Unet convolutional neural network (CNN) architecture implemented with 5 layers was trained to maximize the Dice coefficient, a measure of the correct overlap between the predicted vessels and ground truth labels. Results: The model was able to delineate the intracranial vessels in a held-out test set of normal and tumor MRIs with an overall Dice coefficient of 0.75. While manual segmentation took 1-2 h per patient, model prediction took, on average, 8.3 s per patient. Conclusions: We present a deep learning model that can rapidly and automatically identify the intracranial vessels on pre-operative MRIs in patients with normal vascular anatomy and in patients with intracranial lesions. The methodology developed can be translated to other critical brain structures. This study will serve as a foundation for automated high-resolution ROI segmentation for three-dimensional (3D) modeling and integration into an augmented reality navigation platform.

20.
Elife ; 92020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33025906

RESUMO

Cell-cell interactions influence all aspects of development, homeostasis, and disease. In cancer, interactions between cancer cells and stromal cells play a major role in nearly every step of carcinogenesis. Thus, the ability to record cell-cell interactions would facilitate mechanistic delineation of the role of the cancer microenvironment. Here, we describe GFP-based Touching Nexus (G-baToN) which relies upon nanobody-directed fluorescent protein transfer to enable sensitive and specific labeling of cells after cell-cell interactions. G-baToN is a generalizable system that enables physical contact-based labeling between various human and mouse cell types, including endothelial cell-pericyte, neuron-astrocyte, and diverse cancer-stromal cell pairs. A suite of orthogonal baToN tools enables reciprocal cell-cell labeling, interaction-dependent cargo transfer, and the identification of higher order cell-cell interactions across a wide range of cell types. The ability to track physically interacting cells with these simple and sensitive systems will greatly accelerate our understanding of the outputs of cell-cell interactions in cancer as well as across many biological processes.


Assuntos
Comunicação Celular/fisiologia , Proteínas de Fluorescência Verde/metabolismo , Microscopia/métodos , Animais , Linhagem Celular , Técnicas de Cocultura , Proteínas de Fluorescência Verde/química , Humanos , Lentivirus , Camundongos , Transporte Proteico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...