Linac-based stereotactic radiosurgery (SRS) with planning target volume (PTV) margins <1 mm has become increasingly common in recent years. Optical surface imaging for surface-guided radiation therapy (SGRT) is often used for intra-fraction motion monitoring during these treatments to facilitate the use of a smaller PTV margin by providing real-time quantitative patient positioning information. However, rotating the couch introduces errors to SGRT-reported translations and rotations that can be problematic for SRS treatments with non-coplanar arcs and very small PTV margins.
View Article and Find Full Text PDFA 74-year-old woman with pathologic T4a N1 M0 adenocarcinoma of the cecum, initially treated with right hemicolectomy, developed rising serum carcinoembryonic antigen levels while receiving adjuvant chemotherapy. Re-staging investigations demonstrated two soft tissue metastases in the right abdomen comprised of a retrocolic lesion immediately posterior to the colon and a retroperitoneal lesion with no other sites of metastases. The patient was treated with stereotactic ablative radiotherapy (SABR) to a dose of 40 Gy in five daily fractions to both pericolonic soft tissue metastases simultaneously.
View Article and Find Full Text PDFPurpose: To evaluate the feasibility of an open-source, semi-automated, and reproducible vertex placement tool to improve the efficiency of lattice radiotherapy (LRT) planning. We used polymer gel dosimetry with a Cone Beam CT (CBCT) readout to commission this LRT technique.
Material And Methods: We generated a volumetric modulated arc therapy (VMAT)-based LRT plan on a 2 L NIPAM polymer gel dosimeter using our Eclipse Acuros version 15.
Symbolic numeracy first emerges as children learn the meanings of number words and how to use them to precisely count sets of objects. This development starts before children enter school and forms a foundation for lifelong mathematics achievement. Despite its importance, exactly how children acquire this basic knowledge is unclear.
View Article and Find Full Text PDFThe vertebrate retina is a tractable system for studying control of cell neurogenesis and cell fate specification. During embryonic development, retinal neurogenesis is under strict temporal regulation, with cell types generated in fixed but overlapping temporal intervals. The temporal sequence and relative numbers of retinal cell types generated during development are robust and show minimal experience-dependent variation.
View Article and Find Full Text PDFTo develop and benchmark a novel 3D dose verification technique consisting of polymer gel dosimetry (PGD) with cone-beam-CT (CBCT) readout through a two-institution study. The technique has potential for wide and robust applicability through reliance on CBCT readout..
View Article and Find Full Text PDFZebrafish possess the ability to regenerate dying neurons in response to retinal injury, with both Müller glia and microglia playing integral roles in this response. Resident Müller glia respond to damage by reprogramming and undergoing an asymmetric cell division to generate a neuronal progenitor cell, which continues to proliferate and differentiate into the lost neurons. In contrast, microglia become reactive, phagocytose dying cells, and release inflammatory signals into the surrounding tissue following damage.
View Article and Find Full Text PDFPurpose: Deep learning-based auto-segmentation algorithms can improve clinical workflow by defining accurate regions of interest while reducing manual labor. Over the past decade, convolutional neural networks (CNNs) have become prominent in medical image segmentation applications. However, CNNs have limitations in learning long-range spatial dependencies due to the locality of the convolutional layers.
View Article and Find Full Text PDFMRI-guided neuro interventions require rapid, accurate, and reproducible segmentation of anatomical brain structures for identification of targets during surgical procedures and post-surgical evaluation of intervention efficiency. Segmentation algorithms must be validated and cleared for clinical use. This work introduces a methodology for shape-constrained deformable brain segmentation, describes the quantitative validation used for its clinical clearance, and presents a comparison with manual expert segmentation and FreeSurfer, an open source software for neuroimaging data analysis.
View Article and Find Full Text PDFParents are considered a major resource in children's numeracy development. The relative role of cognitive and motivational parenting practices, however, is unclear given that the two types of practices have largely been studied in isolation. The current study simultaneously estimated the contributions of several cognitive and motivational parenting practices hypothesized to be important, but which may have overlapping effects.
View Article and Find Full Text PDFAims: Most patients experience stable quality of life (QoL) after stereotactic ablative radiotherapy (SABR) treatment for oligometastases. However, a subset of patients experience clinically relevant declines in QoL on post-treatment follow-up. This study aimed to identify risk factors for QoL decline.
View Article and Find Full Text PDFFollowing acute retinal damage, zebrafish possess the ability to regenerate all neuronal subtypes through Müller glia (MG) reprogramming and asymmetric cell division that produces a multipotent Müller glia-derived neuronal progenitor cell (MGPC). This raises three key questions. First, do MG reprogram to a developmental retinal progenitor cell (RPC) state? Second, to what extent does regeneration recapitulate retinal development? And finally, does loss of different retinal cell subtypes induce unique MG regeneration responses? We examined these questions by performing single-nuclear and single-cell RNA-Seq and ATAC-Seq in both developing and regenerating retinas.
View Article and Find Full Text PDFAims: To evaluate longitudinal patient-reported quality of life (QoL) in patients treated with stereotactic ablative radiotherapy (SABR) for oligometastases.
Materials And Methods: The SABR-5 trial was a population-based single-arm phase II study of SABR to up to five sites of oligometastases, conducted in six regional cancer centres in British Columbia, Canada from 2016 to 2020. Prospective QoL was measured using treatment site-specific QoL questionnaires at pre-treatment baseline and at 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after treatment.
Damage to light-sensing photoreceptors (PRs) occurs in highly prevalent retinal diseases. As humans cannot regenerate new PRs, these diseases often lead to irreversible blindness. Intriguingly, animals, such as the zebrafish, can regenerate PRs efficiently and restore functional vision.
View Article and Find Full Text PDFFollowing acute retinal damage, zebrafish possess the ability to regenerate all neuronal subtypes. This regeneration requires Müller glia (MG) to reprogram and divide asymmetrically to produce a multipotent Müller glia-derived neuronal progenitor cell (MGPC). This raises three key questions.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
November 2023
Primary and secondary septa formed during lung development contain a double-layered capillary network. To improve gas exchange, the capillary network is remodeled into a single-layered one, a process that is called microvascular maturation (MVM). It takes place during classical and continued alveolarization.
View Article and Find Full Text PDFAdv Exp Med Biol
August 2023
Nearly a billion people worldwide are affected by vision-impairing conditions, with retinal degenerative diseases being a major cause of blindness. Unfortunately, such diseases are often permanent and progressive, resulting in further degeneration and loss of sight, due to the human retina possessing little, if any, regenerative capacity. Despite numerous efforts and great progress being made to understand the molecular mechanisms of these diseases and possible therapies, the majority of investigations focused on cell-intrinsic factors.
View Article and Find Full Text PDFThe human infant brain automatically extracts number from the environment. A new study recovers an abstract code for number from the brain electrophysiology of sleeping infants.
View Article and Find Full Text PDFChildren appear to have some arithmetic abilities before formal instruction in school, but the extent of these abilities as well as the mechanisms underlying them are poorly understood. Over two studies, an initial exploratory study of preschool children in the U.S.
View Article and Find Full Text PDF. The development of radiation-induced fibrosis after stereotactic ablative radiotherapy (SABR) can obscure follow-up images and delay detection of a local recurrence in early-stage lung cancer patients. The objective of this study was to develop a radiomics model for computer-assisted detection of local recurrence and fibrosis for an earlier timepoint (<1 year) after the SABR treatment.
View Article and Find Full Text PDFThis article describes the dataset applied in the research reported in NeuroImage article "Patient-specific solution of the electrocorticography forward problem in deforming brain" [1] that is available for download from the Zenodo data repository (https://zenodo.org/record/7687631) [2]. Preoperative structural and diffusion-weighted magnetic resonance (MR) and postoperative computed tomography (CT) images of a 12-year-old female epilepsy patient under evaluation for surgical intervention were obtained retrospectively from Boston Children's Hospital.
View Article and Find Full Text PDFBackground: The recent trend toward 10 MV for volumetric radiotherapy treatment such as volumetric modulated arc therapy (VMAT), stereotactic radiosurgery (SRS), and stereotactic ablative body radiotherapy (SABR) introduces photoneutron production, with implications for non-therapeutic patient dose and additional shielding requirements for treatment room design. The sharply nonlinear drop-off in photoneutron production below 10 MV to negligible at 6 MV has scarcely been characterized quantitatively, yet can elucidate important practical insights.
Purpose: To measure photoneutron yields in a medical linac at 8 MV, which may strike a reasonable balance between usefully increased beam penetration and dose rate as compared to 6 MV while reducing photoneutron production which is present at 10 MV.