A Phase I/IIa Study of DHP107, a Novel Oral Paclitaxel Formulation, in Patients with Advanced Solid Tumors or Gastric Cancer

Lessons Learned

Ideally, patients should have access to an oral formulation of paclitaxel, as well as an intravenous formulation, to allow development of regimens exploring alternate schedules and to avoid reactions to Cremophor EL (BASF Corp., Ludwigshafen, Germany, https://www.basf.com).

DHP107 is a novel oral paclitaxel formulation that is a tolerable and feasible regimen for patients with gastric cancer, with data suggesting efficacy similar to that of intravenous paclitaxel.

Background.

We evaluated the maximum tolerated dose (MTD) of DHP107, a novel oral paclitaxel formulation, and the efficacy and safety of the agent in patients with advanced solid tumors.

Patients and Methods.

Phase I study: cohorts of 3–6 patients with advanced solid tumors received escalating DHP107 doses. Phase IIa study: patients with measurable advanced gastric cancer received DHP107, 200 mg/m² b.i.d., on days 1, 8, and 15 every 4 weeks. Pharmacokinetics, safety, and efficacy were analyzed.

Results.

Phase I: 17 patients received a dose-escalating regimen of DHP107, 150–250 mg/m² b.i.d. Dose-limiting toxicities were neutropenia and febrile neutropenia. The MTD (recommended dose) for phase IIa was 200 mg/m² b.i.d. Phase IIa: 11 patients with measurable advanced gastric cancer in whom first-line therapy failed received DHP107 (MTD). Three confirmed partial responses were observed. Median progression-free survival of gastric cancer patients (n = 16) treated at the MTD was 2.97 (95% confidence interval, 1.67–5.40) months (Fig. 1). The most frequent grade 3/4 adverse events were neutropenia (35.3%) and leukopenia (17.6%) at the MTD (phase I and IIa combined; n = 17).

Conclusion.

DHP107 showed good antitumor efficacy and was tolerable. The MTD (200 mg/m² b.i.d.) is recommended for use in further studies comparing DHP107 with standard intravenous paclitaxel therapy. The Oncologist 2017;22:000–000

http://ift.tt/2ku89Lm

An International Vascular Registry Infrastructure for Medical Device Evaluation and Surveillance

Publication date: Available online 14 February 2017
Source:European Journal of Vascular and Endovascular Surgery
Author(s): A. Sedrakyan, J.L. Cronenwett, M. Venermo, L. Kraiss, D. Marinac-Dabic, M. Björck




http://ift.tt/2ku28OV

Neck muscle fatigue differentially alters scapular and humeral kinematics during humeral elevation in subclinical neck pain participants versus healthy controls

Publication date: Available online 14 February 2017
Source:Journal of Electromyography and Kinesiology
Author(s): Mahboobeh Zabihhosseinian, Michael W.R. Holmes, Samuel Howarth, Brad Ferguson, Bernadette Murphy
BackgroundScapular orientation is highly dependent on axioscapular muscle function. This study examined the impact of neck muscle fatigue on scapular and humeral kinematics in participants with and without subclinical neck pain (SCNP) during humeral elevation.MethodsTen SCNP and 10 control participants performed three unconstrained trials of dominant arm humeral elevation in the scapular plane to approximately 120 degrees before and after neck extensor muscle fatigue. Three-dimensional scapular and humeral kinematics were measured during the humeral elevation trials.ResultsHumeral elevation plane angle showed a significant interaction between groups (SCNP vs controls) and trial (pre- vs post-fatigue) (p=.001). Controls began the unconstrained humeral elevation task after fatigue in a more abducted position, (p=.002). Significant baseline differences in scapular rotation existed between the two groups (Posterior/Anterior tilt, p=.04; Internal/External Rotation, p=.001).DiscussionSCNP contributed to altered scapular kinematics. Neck muscle fatigue influenced humeral kinematics in controls but not the SCNP group; suggesting that altered scapular motor control in the SCNP group resulted in an impaired adaption further to the neck muscle fatigue.



http://ift.tt/2l57OR9

Individualized selection of beam angles and treatment isocenter in tangential breast IMRT

Publication date: Available online 14 February 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Joan Penninkhof, Sara Spadola, Sebastiaan Breedveld, Margreet Baaijens, Nico Lanconelli, Ben Heijmen
Purpose/objectivePropose a novel method for individualized selection of beam angles and treatment isocenter in tangential breast IMRT.Methods and MaterialsFor each patient, beam and isocenter selection starts with the fully automatic generation of a large database of IMRT plans (up to 847 in this study), each of these plans belongs to a unique combination of isocenter position, lateral beam angle, and medial beam angle. The imposed hard planning constraint on patient maximum dose may result in plans with unacceptable target dose delivery. Such plans are excluded from further analyses. Due to differences in beam set-up, database plans differ in mean doses in organs-at-risk (OARs). These mean doses are used to construct 2-dimensional graphs, showing relationships between 1) contralateral breast dose and ipsilateral lung dose, and 2) contralateral breast dose and heart dose (analyzed only for left-sided). The graphs can be used for selection of the isocenter and beam angles with the optimal, patient-specific trade-offs between the mean OAR doses. For 30 previously treated patients (15 left-sided and 15 right-sided tumors), graphs were generated considering only the clinically applied isocenter with 121 tangential beam angle pairs. For 20 of the 30 patients, 6 alternative isocenters were investigated as well.ResultsComputation time for automatic generation of 121 IMRT plans took on average 30 minutes. The generated graphs demonstrated large variations in trade-offs between conflicting OAR objectives, depending on beam angles and patient anatomy. For patients with isocenter optimization, 847 IMRT plans were considered. Adding isocenter position optimization next to beam angle optimization had a small impact on the final plan quality.ConclusionA method is proposed for individualized selection of beam angles in tangential breast IMRT. This may be especially important for patients with cardiac risk factors or an enhanced risk for development of contralateral breast cancer.

Teaser

A method for individualized selection of beam angles and treatment isocenter in tangential breast IMRT, based on graphical representations of mean OAR doses in a large database of automatically generated IMRT plans, is presented. The method may be especially useful for patients with cardiac risk factors or an enhanced risk for induction of a tumor in the contralateral breast.


http://ift.tt/2ktFJRL

Salvage treatment options for recurrent seminoma? Expert Opinion Commentary

Publication date: Available online 14 February 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Peter Chung, Padraig Warde




http://ift.tt/2ldlQmg

Development of a Quality and Safety Competency Curriculum for Radiation Oncology Residency: An International Delphi Study

Publication date: Available online 14 February 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Jenna Adleman, Caitlin Gillan, Amanda Caissie, Carol-Anne Davis, Brian Liszewski, Andrea McNiven, Meredith Giuliani
PurposeThe purpose of this study was to develop an entry-to-practice quality and safety competency profile for radiation oncology (RO) residency.Methods and MaterialsA comprehensive list of potential quality and safety competency items was generated from public and professional resources and interprofessional focus groups. Redundant or out-of-scope items were eliminated through investigator consensus. Remaining items were subjected to an international two-round modified Delphi process involving experts in RO, radiation therapy, and medical physics. During Round One, each item was scored independently on a 9-point Likert scale indicating appropriateness for inclusion in the competency profile. Items indistinctly ranked for inclusion or exclusion were reevaluated through web-conference discussion and re-ranked in Round Two.ResultsAn initial 1,211 items were compiled from 32 international sources and distilled to 105 unique potential quality and safety competency items. Fifteen of the 50 invited experts participated in Round One: 10 radiation oncologists, four radiation therapists, and one medical physicist from 13 centres in five countries. Round One rankings resulted in 80 items included, one item excluded, and 24 items indeterminate. Two areas emerged more prominently within the latter group: change management and human factors. Web-conference with five participants resulted in nine of these 24 items edited for content or clarity. In Round Two, 12 participants rescored all indeterminate items resulting in 10 items ranked for inclusion. The final 90 enabling competency items were organized into thematic groups consisting of 18 key competencies under headings adapted from Deming's System of Profound Knowledge.ConclusionsThis quality and safety competency profile may inform minimum training standards for RO residency programs.

Teaser

The purpose of this study was to develop an entry-to-practice quality and safety competency profile for radiation oncology (RO) residency education. An international 2-round modified Delphi process was conducted with participation from 15 experts in radiation oncology representing 13 centres in five countries. Ninety of the initial 105 items were ranked for inclusion in the final competency profile. This profile may form the basis of quality and safety training standards in RO residency programs.


http://ift.tt/2ktKQBc

Predicting patient-specific dosimetric benefits of proton therapy for skull-base tumors using a geometric knowledge-based method

Publication date: Available online 14 February 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): David C. Hall, Alexei V. Trofimov, Brian A. Winey, Norbert J. Liebsch, Harald Paganetti
PurposeTo predict the organ-at-risk (OAR) dose levels achievable with proton beam therapy (PBT), solely based upon the geometric arrangement of the target volume in relation to the OARs. Comparison to an alternative therapy yields a prediction of the patient-specific benefits offered by PBT. This could enable a physician at a hospital without proton capabilities to make a better-informed referral decision, or aid patient selection in model-based clinical trials.Methods and MaterialsSkull-base tumors were chosen to test the method, owing to their geometric complexity and multitude of nearby OARs. By exploiting correlations between dose and distance-to-target in existing PBT plans, models were independently trained for six types of OAR: brainstem, cochlea, optic chiasm, optic nerve, parotid gland and spinal cord. Once trained, the models could estimate the feasible dose-volume histogram and generalized equivalent uniform dose (gEUD) for OAR structures of new patients. Models were trained using 20 patients and validated with a further 21 patients. Validation was achieved by comparing the predicted gEUD to that of the actual PBT plan.ResultsThe predicted and planned gEUD were in good agreement: considering all OARs, the prediction error was +1.4 ± 5.1 Gy (mean ± SD) and Pearson's correlation coefficient was 93%. When compared to an IMRT plan, the model could classify whether an OAR structure would experience a gain with a sensitivity of 93% (95% CI: 87% – 97%) and a specificity of 63% (95% CI: 38% – 84%).ConclusionsWe trained and validated models that quickly and accurately predict the patient-specific benefits of PBT for skull-base tumors. Similar models could be developed for other tumor sites. Such models are useful when an estimation of the feasible benefits of PBT is desired, but the experience and/or resources required for treatment planning are unavailable.

Teaser

This work aims to develop models that can predict the patient-specific benefits offered by proton therapy, solely based upon a patient's geometry. A knowledge-based method trains the models upon geometric patterns observed in a set of existing proton treatment plans for skull base tumors. The models were validated yielding a Pearson's correlation coefficient of 93%; similar models could be trained for other tumor sites and be used to make better-informed referral decisions.


http://ift.tt/2ldpX1E

Open-label study of etanercept treatment in patients with moderate to severe plaque psoriasis who lost a satisfactory response to adalimumab

Summary

Background

Some plaque psoriasis patients experience secondary failure of tumour necrosis factor inhibitor therapy.

Objectives

To evaluate efficacy, safety, and patient-reported outcomes (PROs) with etanercept in patients with secondary adalimumab failure.

Methods

This phase 4, open-label, single-arm, estimation study (NCT01543204) enrolled patients on adalimumab who had achieved static physician global assessment (sPGA) score 0/1 (clear/almost clear). Patients subsequently lost response, defined as sPGA ≥3 or loss of 50% improvement in Psoriasis Area and Severity Index (PASI 50). At baseline, patients had involved body surface area ≥10%, sPGA ≥3, and PASI ≥10. Anti-adalimumab antibodies (ADA) were measured at screening. Patients received etanercept 50mg twice weekly for 12 weeks followed by 50mg weekly. Primary endpoint was sPGA 0/1 at week 12 (intent-to-treat analysis; no hypothesis tested). Additional outcomes included rates of sPGA 0/1, PASI responses, safety, PROs of itch, pain, and flaking, Dermatology Life Quality Index (DLQI), treatment satisfaction, and Work Productivity and Activity Impairment (WPAI).

Results

Sixty-four patients enrolled; 67% had ADA. Week 12 sPGA 0/1 rates (95% confidence interval) were 39.7% (27.6%-52.8%; primary endpoint); and 45.0% (29.3%–61.5%) for ADA-positive and 35.0% (15.4%–59.2%) for ADA-negative patients. Week 12 PASI 75 response rates (95% CI) were 47.5% (31.5%–63.9%) for ADA-positive and 50.0% (27.2%–72.8%) for ADA-negative patients. No new safety signals were observed. PROs of itch, pain, and flaking consistently improved at week 12 and were maintained through week 24.

Conclusions

Psoriasis patients with secondary failure of adalimumab achieved satisfactory response to etanercept regardless of ADA status.

This article is protected by copyright. All rights reserved.

http://ift.tt/2lMFwKs

IFNAR1 Degradation: A New Mechanism for Tumor Immune Evasion?

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Romina E. Araya, Romina S. Goldszmid
Type I interferons have been shown to play a major role in anti-cancer immunity. In this issue of Cancer Cell, Katlinski et al. describe tumor-induced degradation of type I interferon receptor IFNAR1 chain as a new immune-evasion mechanism in colorectal cancers. Stabilizing IFNAR1 inhibits tumor growth and improves immunotherapy efficacy.

Teaser

Type I interferons have been shown to play a major role in anti-cancer immunity. In this issue of Cancer Cell, Katlinski et al. describe tumor-induced degradation of type I interferon receptor IFNAR1 chain as a new immune-evasion mechanism in colorectal cancers. Stabilizing IFNAR1 inhibits tumor growth and improves immunotherapy efficacy.


http://ift.tt/2ldrqVJ

An Oncogenic Role for the Ubiquitin Ligase UBE2O by Targeting AMPK-α2 for Degradation

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): D. Grahame Hardie
There has been controversy regarding the role of AMPK in cancer, some of which may be due to functional differences between isoforms. In this issue of Cancer Cell, Vila et al. report that UBE2O, a ubiquitin ligase overexpressed in some human cancers, specifically triggers the ubiquitination and degradation of AMPK-α2.

Teaser

There has been controversy regarding the role of AMPK in cancer, some of which may be due to functional differences between isoforms. In this issue of Cancer Cell, Vila et al. report that UBE2O, a ubiquitin ligase overexpressed in some human cancers, specifically triggers the ubiquitination and degradation of AMPK-α2.


http://ift.tt/2ktI52Z

Singling Out Chromosome Gains in Tumor Evolution

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Ryan M. Naylor, Jan M. van Deursen
In this issue of Cancer Cell, Sheltzer et al. shed new light on Theodor Boveri's century-old hypothesis by demonstrating that aneuploidy characterized by single-chromosome gains acts to suppress tumorigenesis and that aneuploidy itself is a nidus for genomic instability.

Teaser

In this issue of Cancer Cell, Sheltzer et al. shed new light on Theodor Boveri's century-old hypothesis by demonstrating that aneuploidy characterized by single-chromosome gains acts to suppress tumorigenesis and that aneuploidy itself is a nidus for genomic instability.


http://ift.tt/2ldixM7

Nuclear PKCι-ECT2-Rac1 and Ribosome Biogenesis: A Novel Axis in Lung Tumorigenesis

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Martin J. Baker, Mariana Cooke, Marcelo G. Kazanietz
The RhoGEF Ect2 controls cell division and exerts oncogenic functions in multiple cancers. In this issue of Cancer Cell, Justilien et al. report that Ect2 is required for lung tumorigenesis and identified a role for this GEF in ribosomal RNA (rRNA) synthesis that is mediated by Rac1 and PKCι-dependent phosphorylation.

Teaser

The RhoGEF Ect2 controls cell division and exerts oncogenic functions in multiple cancers. In this issue of Cancer Cell, Justilien et al. report that Ect2 is required for lung tumorigenesis and identified a role for this GEF in ribosomal RNA (rRNA) synthesis that is mediated by Rac1 and PKCι-dependent phosphorylation.


http://ift.tt/2ktFEgY

Awakening of “Schlafen11” to Tackle Chemotherapy Resistance in SCLC

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Katrien Berns, Anton Berns
Chemotherapy resistance arises invariably in small cell lung cancer (SCLC). In this issue of Cancer Cell, Gardner et al. find that in some SCLC, EZH2 mediates resistance via downregulation of Schlafen11 (SLFN11). Combining EZH2 inhibition with chemotherapy effectively overcomes drug resistance of xenografted SCLC, holding promise for new treatment paradigms.

Teaser

Chemotherapy resistance arises invariably in small cell lung cancer (SCLC). In this issue of Cancer Cell, Gardner et al. find that in some SCLC, EZH2 mediates resistance via downregulation of Schlafen11 (SLFN11). Combining EZH2 inhibition with chemotherapy effectively overcomes drug resistance of xenografted SCLC, holding promise for new treatment paradigms.


http://ift.tt/2ldg6cd

Pheochromocytomas and Paragangliomas, Genetically Diverse and Minimalist, All at Once!

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Patricia L.M. Dahia
Pheochromocytomas and paragangliomas are infrequent, genetically heterogeneous neuroendocrine tumors. In this issue of Cancer Cell, Fishbein et al. report novel driver genes, pathogenic mechanisms, and markers of malignancy. Notably, the new findings support the long-held view that these tumors distinctively arise from a single driver event, either inherited or acquired.

Teaser

Pheochromocytomas and paragangliomas are infrequent, genetically heterogeneous neuroendocrine tumors. In this issue of Cancer Cell, Fishbein et al. report novel driver genes, pathogenic mechanisms, and markers of malignancy. Notably, the new findings support the long-held view that these tumors distinctively arise from a single driver event, either inherited or acquired.


http://ift.tt/2ktMXoX

Liquid Biopsies, What We Do Not Know (Yet)

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Alberto Bardelli, Klaus Pantel
The inherent molecular heterogeneity of metastatic tumors and the ability of cancer genomes to dynamically evolve are not properly captured by tissue specimens. Analysis of cell-free DNA and circulating tumor cells has the potential to change clinical practice by exploiting blood rather than tissue as a source of information. Liquid biopsies are already used to monitor disease response and track the emergence of drug resistance. The suitability of blood-based molecular profiles for early detection and monitoring minimal residual disease is being evaluated. In this review, we address open questions in this fast-evolving field of research.

Teaser

The inherent molecular heterogeneity of metastatic tumors and the ability of cancer genomes to dynamically evolve are not properly captured by tissue specimens. Analysis of cell-free DNA and circulating tumor cells has the potential to change clinical practice by exploiting blood rather than tissue as a source of information. Liquid biopsies are already used to monitor disease response and track the emergence of drug resistance. The suitability of blood-based molecular profiles for early detection and monitoring minimal residual disease is being evaluated. In this review, Bardelli and Pantel address open questions in this fast-evolving field of research.


http://ift.tt/2ldndS6

Inactivation of Interferon Receptor Promotes the Establishment of Immune Privileged Tumor Microenvironment

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Kanstantsin V. Katlinski, Jun Gui, Yuliya V. Katlinskaya, Angelíca Ortiz, Riddhita Chakraborty, Sabyasachi Bhattacharya, Christopher J. Carbone, Daniel P. Beiting, Melanie A. Girondo, Amy R. Peck, Ellen Puré, Priya Chatterji, Anil K. Rustgi, J. Alan Diehl, Constantinos Koumenis, Hallgeir Rui, Serge Y. Fuchs
Refractoriness of solid tumors, including colorectal cancers (CRCs), to immunotherapies is attributed to the immunosuppressive tumor microenvironment that protects malignant cells from cytotoxic T lymphocytes (CTLs). We found that downregulation of the type I interferon receptor chain IFNAR1 occurs in human CRC and mouse models of CRC. Downregulation of IFNAR1 in tumor stroma stimulated CRC development and growth, played a key role in formation of the immune-privileged niche, and predicted poor prognosis in human CRC patients. Genetic stabilization of IFNAR1 improved CTL survival and increased the efficacy of the chimeric antigen receptor T cell transfer and PD-1 inhibition. Likewise, pharmacologic stabilization of IFNAR1 suppressed tumor growth providing the rationale for upregulating IFNAR1 to improve anti-cancer therapies.

Graphical abstract

Teaser

Katlinski et al. show reduced type I interferon receptor chain IFNAR1 in colorectal cancer (CRC) stroma, which is important in forming the immune-privileged niche to support CRC development and growth. Stabilization of IFNAR1 improves cytotoxic T lymphocyte survival and suppresses tumor growth.


http://ift.tt/2ktLvCK

Characterization of Human Cancer Cell Lines by Reverse-phase Protein Arrays

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Jun Li, Wei Zhao, Rehan Akbani, Wenbin Liu, Zhenlin Ju, Shiyun Ling, Christopher P. Vellano, Paul Roebuck, Qinghua Yu, A. Karina Eterovic, Lauren A. Byers, Michael A. Davies, Wanleng Deng, Y.N. Vashisht Gopal, Guo Chen, Erika M. von Euw, Dennis Slamon, Dylan Conklin, John V. Heymach, Adi F. Gazdar, John D. Minna, Jeffrey N. Myers, Yiling Lu, Gordon B. Mills, Han Liang
Cancer cell lines are major model systems for mechanistic investigation and drug development. However, protein expression data linked to high-quality DNA, RNA, and drug-screening data have not been available across a large number of cancer cell lines. Using reverse-phase protein arrays, we measured expression levels of ∼230 key cancer-related proteins in >650 independent cell lines, many of which have publically available genomic, transcriptomic, and drug-screening data. Our dataset recapitulates the effects of mutated pathways on protein expression observed in patient samples, and demonstrates that proteins and particularly phosphoproteins provide information for predicting drug sensitivity that is not available from the corresponding mRNAs. We also developed a user-friendly bioinformatic resource, MCLP, to help serve the biomedical research community.

Graphical abstract

Teaser

Li et al. analyze the levels of cancer-related total and phosphorylated proteins using RPPA in a large set of human cancer cell lines, many also with DNA, RNA, and drug-screening data available. These proteins can recapitulate mutational patterns seen in patients and show ability to predict drug sensitivity.


http://ift.tt/2ktI4Mt

Chemosensitive Relapse in Small Cell Lung Cancer Proceeds through an EZH2-SLFN11 Axis

Publication date: 13 February 2017
Source:Cancer Cell, Volume 31, Issue 2
Author(s): Eric E. Gardner, Benjamin H. Lok, Valentina E. Schneeberger, Patrice Desmeules, Linde A. Miles, Paige K. Arnold, Andy Ni, Inna Khodos, Elisa de Stanchina, Thuyen Nguyen, Julien Sage, John E. Campbell, Scott Ribich, Natasha Rekhtman, Afshin Dowlati, Pierre P. Massion, Charles M. Rudin, John T. Poirier
Small cell lung cancer is initially highly responsive to cisplatin and etoposide but in almost every case becomes rapidly chemoresistant, leading to death within 1 year. We modeled acquired chemoresistance in vivo using a series of patient-derived xenografts to generate paired chemosensitive and chemoresistant cancers. Multiple chemoresistant models demonstrated suppression of SLFN11, a factor implicated in DNA-damage repair deficiency. In vivo silencing of SLFN11 was associated with marked deposition of H3K27me3, a histone modification placed by EZH2, within the gene body of SLFN11, inducing local chromatin condensation and gene silencing. Inclusion of an EZH2 inhibitor with standard cytotoxic therapies prevented emergence of acquired resistance and augmented chemotherapeutic efficacy in both chemosensitive and chemoresistant models of small cell lung cancer.

Graphical abstract

Teaser

By generating paired chemonaive and chemoresistant small cell lung cancer (SCLC) patient-derived xenograft models, Gardner et al. find that EZH2 promotes chemoresistance by epigenetically silencing SLFN11. EZH2 inhibition prevents acquisition of chemoresistance and improves chemotherapeutic efficacy in SCLC.


http://ift.tt/2ktIqm6

Shape-aware Surface Reconstruction from Sparse 3D Point-Clouds

Publication date: Available online 14 February 2017
Source:Medical Image Analysis
Author(s): Florian Bernard, Luis Salamanca, Johan Thunberg, Alexander Tack, Dennis Jentsch, Hans Lamecker, Stefan Zachow, Frank Hertel, Jorge Goncalves, Peter Gemmar
The reconstruction of an object's shape or surface from a set of 3D points plays an important role in medical image analysis, e.g. in anatomy reconstruction from tomographic measurements or in the process of aligning intra-operative navigation and preoperative planning data. In such scenarios, one usually has to deal with sparse data, which significantly aggravates the problem of reconstruction. However, medical applications often provide contextual information about the 3D point data that allow to incorporate prior knowledge about the shape that is to be reconstructed. To this end, we propose the use of a statistical shape model (SSM) as a prior for surface reconstruction. The SSM is represented by a point distribution model (PDM), which is associated with a surface mesh. Using the shape distribution that is modelled by the PDM, we formulate the problem of surface reconstruction from a probabilistic perspective based on a Gaussian Mixture Model (GMM). In order to do so, the given points are interpreted as samples of the GMM. By using mixture components with anisotropic covariances that are "oriented" according to the surface normals at the PDM points, a surface-based fitting is accomplished. Estimating the parameters of the GMM in a maximum a posteriori manner yields the reconstruction of the surface from the given data points. We compare our method to the extensively used Iterative Closest Points method on several different anatomical datasets/SSMs (brain, femur, tibia, hip, liver) and demonstrate superior accuracy and robustness on sparse data.

Graphical abstract

http://ift.tt/2lMiseH

Food and Beverage Selection Patterns among Menu Label Users and Nonusers: Results from a Cross-Sectional Study

Publication date: Available online 13 February 2017
Source:Journal of the Academy of Nutrition and Dietetics
Author(s): Jessie Gruner, Punam Ohri-Vachaspati
BackgroundBy May 5, 2017, restaurants with 20 or more locations nationwide will be required to post calorie information on menus and menu boards. Previous research shows that those who use menu labels purchase fewer calories, but how users are saving calories is unknown.ObjectiveTo assess food and beverage selection patterns among menu label users and nonusers.DesignSecondary, cross-sectional analysis using data from a study examining sociodemographic disparities in menu label usage at a national fast-food restaurant chain.Participants/settingParticipants were recruited outside restaurant locations, using street-intercept survey methodology. Consenting customers submitted receipts and completed a brief oral survey. Receipt data were used to categorize food and beverage purchases.Main outcome measureSide, beverage, and entrée purchases. Sides and beverages were classified as healthier and less-healthy options consistent with the 2015 Dietary Guidelines for Americans. Healthier options contained items promoted in the guidelines, such as whole fruits, vegetables, low-fat dairy, and 100% fruit juice; less-healthy options contained solid fat or added sugar. Entrées were categorized as lower-, medium-, and higher-calorie options, based on quartile cutoffs.Statistical analysesMultinomial logistic regression models were used to estimate prevalence ratios (PRs) for purchases among menu label users and nonusers, controlling for sociodemographic characteristics and total price paid.ResultsHealthier sides were selected by 7.5% of users vs 2.5% of nonusers; healthier beverages were selected by 34.0% of users vs 11.6% of nonusers; and lowest-calorie entrées were selected by 28.3% of users vs 30.1% of nonusers. Compared with nonusers (n=276), users (n=53) had a higher probability of purchasing healthier sides (PR=5.44; P=0.034), and healthier beverages (PR=3.37; P=0.005). No significant differences were seen in the purchasing patterns of entrées.ConclusionsTargeting educational campaigns to side and beverage purchasing behaviors may increase the effectiveness of menu labeling.



http://ift.tt/2l4LfvY