Minute-scale oscillatory sequences in medial entorhinal cortex.

The medial entorhinal cortex (MEC) hosts many of the brain's circuit elements for spatial navigation and episodic memory, operations that require neural activity to be organized across long durations of experience. Whereas location is known to be encoded by spatially tuned cell types in this brain region, little is known about how the activity of entorhinal cells is tied together over time at behaviourally relevant time scales, in the second-to-minute regime. Here we show that MEC neuronal activity has the capacity to be organized into ultraslow oscillations, with periods ranging from tens of seconds to minutes.

Deep learning MRI-only synthetic-CT generation for pelvis, brain and head and neck cancers.

Background And Purpose: MRI-only planning relies on dosimetrically accurate synthetic-CT (sCT) generation to allow dose calculation. Here we validated the dosimetric accuracy of sCTs generated using a deep learning algorithm for pelvic, brain and head and neck (H&N) cancer sites using variable MRI data from multiple scanners.

Methods: sCT generation models were trained using a cycle-GAN algorithm, using paired MRI-CT patient data.

CBCT-Based Dose Monitoring and Adaptive Planning Triggers in Head and Neck PBS Proton Therapy.

Purpose: To investigate the feasibility of using cone-beam computed tomography (CBCT)-derived synthetic CTs to monitor the daily dose and trigger a plan review for adaptive proton therapy (APT) in head and neck cancer (HNC) patients.

Methods: For 84 HNC patients treated with proton pencil-beam scanning (PBS), same-day CBCT and verification CT (vfCT) pairs were retrospectively collected. The ground truth CT (gtCT) was created by deforming the vfCT to the same-day CBCT, and it was then used as a dosimetric baseline and for establishing plan review trigger recommendations.

An optimized framework for cone-beam computed tomography-based online evaluation for proton therapy.

Background: Clinical evidence has demonstrated that proton therapy can achieve comparable tumor control probabilities compared to conventional photon therapy but with the added benefit of sparing healthy tissues. However, proton therapy is sensitive to inter-fractional anatomy changes. Online pre-fraction evaluation can effectively verify proton dose before delivery to patients, but there is a lack of guidelines for implementing this workflow.

Clinical evaluation of synthetic computed tomography methods in adaptive proton therapy of lung cancer patients.

Background And Purpose: Efficient workflows for adaptive proton therapy are of high importance. This study evaluated the possibility to replace repeat-CTs (reCTs) with synthetic CTs (sCTs), created based on cone-beam CTs (CBCTs), for flagging the need of plan adaptations in intensity-modulated proton therapy (IMPT) treatment of lung cancer patients.

Materials And Methods: Forty-two IMPT patients were retrospectively included.

Object-centered population coding in CA1 of the hippocampus.

Objects and landmarks are crucial for guiding navigation and must be integrated into the cognitive map of space. Studies of object coding in the hippocampus have primarily focused on activity of single cells. Here, we record simultaneously from large numbers of hippocampal CA1 neurons to determine how the presence of a salient object in the environment alters single-neuron and neural-population activity of the area.

Daily dose evaluation based on corrected CBCTs for breast cancer patients: accuracy of dose and complication risk assessment.

Objectives: The goal of this study is to validate different CBCT correction methods to select the superior method that can be used for dose evaluation in breast cancer patients with large anatomical changes treated with photon irradiation.

Materials And Method: Seventy-six breast cancer patients treated with a partial VMAT photon technique (70% conformal, 30% VMAT) were included in this study. All patients showed at least a 5 mm variation (swelling or shrinkage) of the breast on the CBCT compared to the planning-CT (pCT) and had a repeat-CT (rCT) for dose evaluation acquired within 3 days of this CBCT.

Visual stimulus features that elicit activity in object-vector cells.

Object-vector (OV) cells are cells in the medial entorhinal cortex (MEC) that track an animal's distance and direction to objects in the environment. Their firing fields are defined by vectorial relationships to free-standing 3-dimensional (3D) objects of a variety of identities and shapes. However, the natural world contains a panorama of objects, ranging from discrete 3D items to flat two-dimensional (2D) surfaces, and it remains unclear what are the most fundamental features of objects that drive vectorial responses.

Technical Note: Efficient and accurate MRI-only based treatment planning of the prostate using bulk density assignment through atlas-based segmentation.

Purpose: This study investigates the dosimetric accuracy as well as the robustness of a bulk density assignment approach to magnetic resonance imaging (MRI)-only based treatment planning of the prostate, with bulk density regions automatically identified using atlas-based segmentation (ABS).

Methods: Twenty prostate radiotherapy patients received planning computed tomography (CT) and MRI scans and were treated with volumetric modulated arc therapy (VMAT). Two bulk densities were set, one for bone and one for soft tissue.

EndoVAC hybrid therapy for salvage of patients with infected femoral artery reconstructions.

Background: EndoVAC hybrid therapy for infected femoral artery reconstructions consists of endovascular relining with a stent graft, surgical debridement and vacuum-assisted wound closure (VAC), and may be considered as a bailout procedure. The aim of this study was to analyze differences in risk factors of patients receiving EndoVAC compared to standard VAC therapy for perivascular infected femoral artery reconstructions, and to describe the technique, complications and outcome of EndoVAC therapy.

Material And Methods: Retrospective analysis of 183 patients receiving VAC or EndoVAC therapy for perivascular infections in the groin from January 2004 to December 2017 was performed.

Object-vector coding in the medial entorhinal cortex.

The hippocampus and the medial entorhinal cortex are part of a brain system that maps self-location during navigation in the proximal environment. In this system, correlations between neural firing and an animal's position or orientation are so evident that cell types have been given simple descriptive names, such as place cells, grid cells, border cells and head-direction cells. While the number of identified functional cell types is growing at a steady rate, insights remain limited by an almost-exclusive reliance on recordings from rodents foraging in empty enclosures that are different from the richly populated, geometrically irregular environments of the natural world.

MR and CT data with multiobserver delineations of organs in the pelvic area-Part of the Gold Atlas project.

Purpose: We describe a public dataset with MR and CT images of patients performed in the same position with both multiobserver and expert consensus delineations of relevant organs in the male pelvic region. The purpose was to provide means for training and validation of segmentation algorithms and methods to convert MR to CT like data, i.e.

Outcome and Complications Using Negative Pressure Wound Therapy in the Groin for Perivascular Surgical Site Infections after Vascular Surgery.

Background: The aim of this study was to investigate graft preservation, major bleeding, and reinfection rate using negative pressure wound therapy (NPWT) for perivascular surgical site infections (SSIs) in the groin after vascular surgery and factors associated with failure of treatment.

Methods: Retrospective data were collected during 2004-2015. Failure of wound treatment was defined as a wound not healed within 4 months, visible graft material or native artery after 1 month, bleeding from the wound leading to discontinuation of treatment, or death or amputation due to the groin infection.