830 research outputs found
Radiation Maculopathy After Proton Beam Therapy for Uveal Melanoma: Optical Coherence Tomography Angiography Alterations Influencing Visual Acuity.
To analyze microvascular and structural changes in radiation maculopathy and their influence on visual acuity (VA), using optical coherence tomography (OCT) and OCT angiography (OCTA).
This was a retrospective analysis of consecutive patients with radiation maculopathy, 12 months or more after proton-beam irradiation for uveal melanoma, imaged with fluorescein angiography, OCT, and OCTA. Clinical parameters potentially affecting VA were recorded, including OCTA-derived metrics: foveal avascular zone (FAZ) area, vascular density, and local fractal dimension of the superficial (SCP) and deep capillary plexuses (DCP). Nonirradiated fellow eyes served as controls.
Ninety-three patients were included. FAZ was larger, while SCP/DCP capillary density and local fractal dimension were lower in the 35 irradiated than in the 35 fellow eyes (P < 0.0001). Microvascular alterations graded on fluorescein angiography (minimally damaged/disrupted/disorganized) were correlated to FAZ area and SCP/DCP density on OCTA (P < 0.01). By univariate analysis, worse VA was associated to macular detachment at presentation (P = 0.024), total macular irradiation (P = 0.0008), higher central macular thickness (CMT) (P = 0.019), higher absolute CMT variation (P < 0.0001), cystoid edema (P = 0.030), ellipsoid zone disruption (P = 0.002), larger FAZ (P < 0.0001), lower SCP (P = 0.001) and DCP capillary density (P < 0.0001), and lower SCP (P = 0.009) and DCP local fractal dimension (P < 0.0001). Two multivariate models with either capillary density or fractal dimension as covariate showed that younger age (P = 0.014/0.017), ellipsoid zone disruption (P = 0.034/0.019), larger FAZ (P = 0.0006/0.002), and lower DCP density (P = 0.008) or DCP fractal dimension (P = 0.012), respectively, were associated with worse VA.
VA of eyes with radiation maculopathy is influenced by structural and microvascular factors identified with OCTA, including FAZ area and DCP integrity
EIGHTEEN-MONTH RESULTS OF INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR ON VISION AND MICROCIRCULATION IN RADIATION MACULOPATHY.
To evaluate 18 months' results of a strict anti-vascular endothelial growth factor protocol for radiation maculopathy following proton therapy in choroidal melanoma.
Retrospective, comparative, nonrandomized study of 74 radiation maculopathy patients presenting macular lipid deposits, hemorrhages, microaneurysms, cystoid edema, nerve layer infarction, telangiectasia, or capillary nonperfusion. The study group included 52 consecutive patients injected with intravitreal anti-vascular endothelial growth factors (bevacizumab/ranibizumab: 46/6) every two months for the first and every 3 months for the second year, with minimum 12 months' follow-up. The control group consisted of 22 patients having declined this treatment. Best-corrected visual acuity, spectral domain-optical coherence tomography and optical coherence tomography angiography were recorded at baseline, 6, 12, and 18 months. The foveal avascular zone and capillary density were measured at the superficial capillary plexus.
Radiation maculopathy was diagnosed at 2 years (1.5-3.5) after proton therapy. Best-corrected visual acuity at baseline, 12 and 18 months improved in the study group from 0.45, 0.3 to 0.2 logarithm of the minimum angle of resolution, but decreased in the control group from 0.5, 0.9 to 1.0 logarithm of the minimum angle of resolution respectively (P < 0.001 at 12 months). Simultaneously, foveal avascular zone enlargement was less in the study (from 0.377, 0.665 to 0.744 mm2) than control group (from 0.436, 1.463 to 2.638 mm2) (P = 0.05 at 12 months). CMT (280 and 276 µm) and capillary density (37% and 38%, at baseline, respectively) did not evolve significantly different.
Intravitreal anti-vascular endothelial growth factors, every 2 months for the first and every 3 months for the second year, slow down, over up to 18 months, vision loss and anatomical degradation in radiation maculopathy following proton therapy for choroidal melanoma
Proton Therapy for Uveal Melanoma in 43 Juvenile Patients: Long-Term Results.
PURPOSE: To examine the metastatic and survival rates, eye retention probability, and the visual outcomes of juvenile patients after proton beam radiotherapy (PBRT) for uveal melanoma (UM).
DESIGN: Retrospective case-factor matched control study.
PARTICIPANTS AND CONTROLS: Forty-three patients younger than 21 years treated with PBRT for UM were compared with 129 matched adult control patients.
METHODS: Information on patient demographics and clinical characteristics were recorded before and after treatment from patients' files. The control group was composed of adult patients (>21 years) matched for tumor size (largest tumor diameter, ±2 mm; height, ±2 mm) and anterior margin location (iris, ciliary body, pre-equatorial or postequatorial choroid). For each juvenile patient, 3 adults were selected.
MAIN OUTCOME MEASURES: Comparing outcomes of juvenile and adult patients in terms of metastatic and eye retention rates using the log-rank statistic, relative survival using the Hakulinen method, as well as their visual outcomes.
RESULTS: Forty-three juvenile and 129 control cases were reviewed. The metastatic rate at 10 years was significantly lower in juvenile UM patients than in adult controls (11% vs. 34%; P <0.01), with an associated relative survival rate of 93% versus 65% (P = 0.02). Six juvenile patients (14%) demonstrated metastases. One patient underwent enucleation because of a presumed local tumor recurrence and 4 additional patients underwent enucleation because of complications (9.3%). In the adult control group, 27% (n = 35) of matched patients demonstrated metastases, there were 2 cases of local recurrence, and 16% (n = 21) underwent enucleation because of complications. A visual acuity of more than 0.10 was maintained in most cases, without any significant differences before or after treatment observed between both groups.
CONCLUSIONS: After PBRT, metastatic and survival rates are significantly better for juvenile than for adult patients with UM. Clinically, juvenile and adult eyes react similarly to PBRT, with patients having a comparable eye retention probability and maintaining a useful level of vision in most cases. This is the largest case-control study of proton therapy in juvenile eyes to date and further validates PBRT as an appropriate conservative treatment for UM in patients younger than 21 years
An exploratory canonical analysis approach for multinomial populations based on the -divergence measure
summary:In this paper we consider an exploratory canonical analysis approach for multinomial population based on the -divergence measure. We define the restricted minimum -divergence estimator, which is seen to be a generalization of the restricted maximum likelihood estimator. This estimator is then used in -divergence goodness-of-fit statistics which is the basis of two new families of statistics for solving the problem of selecting the number of significant correlations as well as the appropriateness of the model
Chronic Pancreatitis and Neoplasia: Correlation or Coincidence
Any link between pancreatic carcinoma and chronic pancreatitis could reflect the malignant potential of a chronic inflammatory process. Four patients with ductal adenocarcinomas had a long history of pancreatic pain (median duration 5 years) and showed clearcut evidence of chronic pancreatitis “downstream” of the tumour. Four were alcoholics and two heavy smokers. These four cases arose within a surgical series of approximately 250 patients with chronic pancreatitis, giving an incidence of 1.6 per cent. The incidence and anatomical distribution of carcinoma and chronic pancreatitis could possibly be consistent with a casual relationship
UV light signature in conjunctival melanoma; not only skin should be protected from solar radiation.
Beyond Correlation Filters: Learning Continuous Convolution Operators for Visual Tracking
Discriminative Correlation Filters (DCF) have demonstrated excellent
performance for visual object tracking. The key to their success is the ability
to efficiently exploit available negative data by including all shifted
versions of a training sample. However, the underlying DCF formulation is
restricted to single-resolution feature maps, significantly limiting its
potential. In this paper, we go beyond the conventional DCF framework and
introduce a novel formulation for training continuous convolution filters. We
employ an implicit interpolation model to pose the learning problem in the
continuous spatial domain. Our proposed formulation enables efficient
integration of multi-resolution deep feature maps, leading to superior results
on three object tracking benchmarks: OTB-2015 (+5.1% in mean OP), Temple-Color
(+4.6% in mean OP), and VOT2015 (20% relative reduction in failure rate).
Additionally, our approach is capable of sub-pixel localization, crucial for
the task of accurate feature point tracking. We also demonstrate the
effectiveness of our learning formulation in extensive feature point tracking
experiments. Code and supplementary material are available at
http://www.cvl.isy.liu.se/research/objrec/visualtracking/conttrack/index.html.Comment: Accepted at ECCV 201
Multimodale Bildgebung eines retinalen Astrozyten-Hamartoms assoziert mit angeborener Hypertrophie des retinalen Pigmentepithels [Multimodal Imaging of Retinal Astrocytic Hamartoma Associated with Congenital Hypertrophy of Retinal Pigment Epithelium]
Hamartoma is a nodular malformation, with a single or multiple malformations, it is a recognized prenatal developmental abnormality. This benign tumor lesion has the same histological components of normal parenchyma, but these components are arranged haphazardly which disrupts normal function. Hamartomas usually remain connected with the tissue of origin; as is the case with pulmonary hamartoma or the splenic hamartoma. The exact incidence of retinal astrocytic hamartoma (RAH) is not well known, but it is estimated at one case per 100 000 births per year [1]. The astrocytic hamartoma is a neuroglial tissue and produces astrocytes within the optic nerve [2], and consequently it often appears within papillary region
Vacuum-assisted breast biopsy in close proximity to the skin: a case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Incorporating the value of slots in airport slot scheduling decisions
Airport slot allocation is the dominant mechanism for managing capacity at congested airports outside the United States. Current practice is facilitated via expert systems software that apply a complex decision process defined by various criteria, rules and priorities. It is acknowledged that mathematical programming may result in more efficient airport slot schedules. Yet, the incorporation of all the regulations and characteristics of the decision process results in complex mathematical formulations and increased computational times. At the same time, existing models assume that a “slot is a slot” without taking into account the differences in the characteristics and significance of each slot. In this work, through a multi-criteria – multi-stakeholder approach, we introduce a slot valuation index (SVI) that considers the attributes of each airport slot while simultaneously incorporating the preferences of all participating groups of stakeholders. We move beyond the proposal of the SVI by devising a two-stage solution approach that employs the SVI as a relative importance weight in the objective functions of optimisation models. Our approach is able to address additional policy requirements, criteria and slot characteristics while preserving computational tractability
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