Patient-specific model-based segmentation of brain tumors in 3D intraoperative ultrasound images

Abstract

Purpose

Intraoperative ultrasound (iUS) imaging is commonly used to support brain tumor operation. The tumor segmentation in the iUS images is a difficult task and still under improvement because of the low signal-to-noise ratio. The success of automatic methods is also limited due to the high noise sensibility. Therefore, an alternative brain tumor segmentation method in 3D-iUS data using a tumor model obtained from magnetic resonance (MR) data for local MR–iUS registration is presented in this paper. The aim is to enhance the visualization of the brain tumor contours in iUS.

Methods

A multistep approach is proposed. First, a region of interest (ROI) based on the specific patient tumor model is defined. Second, hyperechogenic structures, mainly tumor tissues, are extracted from the ROI of both modalities by using automatic thresholding techniques. Third, the registration is performed over the extracted binary sub-volumes using a similarity measure based on gradient values, and rigid and affine transformations. Finally, the tumor model is aligned with the 3D-iUS data, and its contours are represented.

Results

Experiments were successfully conducted on a dataset of 33 patients. The method was evaluated by comparing the tumor segmentation with expert manual delineations using two binary metrics: contour mean distance and Dice index. The proposed segmentation method using local and binary registration was compared with two grayscale-based approaches. The outcomes showed that our approach reached better results in terms of computational time and accuracy than the comparative methods.

Conclusion

The proposed approach requires limited interaction and reduced computation time, making it relevant for intraoperative use. Experimental results and evaluations were performed offline. The developed tool could be useful for brain tumor resection supporting neurosurgeons to improve tumor border visualization in the iUS volumes.

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Cancers, Vol. 10, Pages 19: EpCAM Immunotherapy versus Specific Targeted Delivery of Drugs

Cancers, Vol. 10, Pages 19: EpCAM Immunotherapy versus Specific Targeted Delivery of Drugs

Cancers doi: 10.3390/cancers10010019

Authors: Joanna Macdonald Justin Henri Kislay Roy Emma Hays Michelle Bauer Rakesh Veedu Normand Pouliot Sarah Shigdar

The epithelial cell adhesion molecule (EpCAM), or CD326, was one of the first cancer associated biomarkers to be discovered. In the last forty years, this biomarker has been investigated for use in personalized cancer therapy, with the first monoclonal antibody, edrecolomab, being trialled in humans more than thirty years ago. Since then, several other monoclonal antibodies have been raised to EpCAM and tested in clinical trials. However, while monoclonal antibody therapy has been investigated against EpCAM for almost 40 years as primary or adjuvant therapy, it has not shown as much promise as initially heralded. In this review, we look at the reasons why and consider alternative targeting options, such as aptamers, to turn this almost ubiquitously expressed epithelial cancer biomarker into a viable target for future personalized therapy.

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Cancers, Vol. 10, Pages 17: Advances in Molecular Profiling and Categorisation of Pancreatic Adenocarcinoma and the Implications for Therapy

Cancers, Vol. 10, Pages 17: Advances in Molecular Profiling and Categorisation of Pancreatic Adenocarcinoma and the Implications for Therapy

Cancers doi: 10.3390/cancers10010017

Authors: Rille Pihlak Jamie Weaver Juan Valle Mairéad McNamara

Pancreatic ductal adenocarcinoma (PDAC) continues to be a disease with poor outcomes and short-lived treatment responses. New information is emerging from genome sequencing identifying potential subgroups based on somatic and germline mutations. A variety of different mutations and mutational signatures have been identified; the driver mutation in around 93% of PDAC is KRAS, with other recorded alterations being SMAD4 and CDKN2A. Mutations in the deoxyribonucleic acid (DNA) damage repair pathway have also been investigated in PDAC and multiple clinical trials are ongoing with DNA-damaging agents. Rare mutations in BRAF and microsatellite instability (MSI) have been reported in about 1–3% of patients with PDAC, and agents used in other cancers to target these have also shown some promise. Immunotherapy is a developing field, but has failed to demonstrate benefits in PDAC to date. While many trials have failed to improve outcomes in this deadly disease, there is optimism that by developing a better understanding of the translational aspects of this cancer, future informed therapeutic strategies may prove more successful.

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In This Issue

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Issue Information

Cover of this issue. GFP-positive circulating tumor cells. See also Takakura et al. (pp. 231–240 of this issue).

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Assessment of the permeability properties of cryopreservation outer bags used in NHSBT

Abstract

This study was carried out to investigate leakage/transport across the bag material of six outer cryopreservation bags in common use within NHS Blood and Transplant. In order to do this two different leak testing procedures; coloured dye and hydrogen tracer gas, were used. The data obtained show that a coloured dye cannot permeate through the materials both at room temperature and following storage at liquid nitrogen temperature (− 196 °C). In addition, when filled with the smallest elemental molecule, hydrogen, in the form of a tracer gas, all of the bags only allowed trace amounts of hydrogen to escape, either through the seal or the bag material. The data indicated that each of the bag materials tested would be capable of preventing bacterial or viral cross-contamination as long as the material remained intact.

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IJMS, Vol. 19, Pages 229: The Influence of EGFR Inactivation on the Radiation Response in High Grade Glioma

IJMS, Vol. 19, Pages 229: The Influence of EGFR Inactivation on the Radiation Response in High Grade Glioma

International Journal of Molecular Sciences doi: 10.3390/ijms19010229

Authors: Oana Alexandru Stefana Purcaru Ligia Tataranu Laura Lucan Juan Castro Catalin Folcuţi Stefan-Alexandru Artene Cristian Tuţă Anica Dricu

Lack of effectiveness of radiation therapy may arise from different factors such as radiation induced receptor tyrosine kinase activation and cell repopulation; cell capability to repair radiation induced DNA damage; high grade glioma (HGG) tumous heterogeneity, etc. In this study, we analyzed the potential of targeting epidermal growth factor receptor (EGFR) in inducing radiosensitivity in two human HGG cell lines (11 and 15) that displayed similar growth patterns and expressed the receptor protein at the cell surface. We found that 15 HGG cells that express more EGFR at the cell surface were more sensitive to AG556 (an EGFR inhibitor), compared to 11 HGG cells. Although in line 15 the effect of the inhibitor was greater than in line 11, it should be noted that the efficacy of this small-molecule EGFR inhibitor as monotherapy in both cell lines has been modest, at best. Our data showed a slight difference in the response to radiation of the HGG cell lines, three days after the treatment, with line 15 responding better than line 11. However, both cell lines responded to ionizing radiation in the same way, seven days after irradiation. EGFR inhibition induced radiosensitivity in 11 HGG cells, while, in 15 HGG cells, the effect of AG556 treatment on radiation response was almost nonexistent.

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