Skin3D: Detection and longitudinal tracking of pigmented skin lesions in 3D total-body textured meshes

We present an automated approach to detect and longitudinally track skin lesions on 3D total-body skin surface scans. The acquired 3D mesh of the subject is unwrapped to a 2D texture image, where a trained objected detection model, Faster R-CNN, localizes the lesions within the 2D domain. These detected skin lesions are mapped back to the 3D surface of the subject and, for subjects imaged multiple times, we construct a graph-based matching procedure to longitudinally track lesions that considers the anatomical correspondences among pairs of meshes and the geodesic proximity of corresponding lesions and the inter-lesion geodesic distances.We evaluated the proposed approach using 3DBodyTex, a publicly available dataset composed of 3D scans imaging the coloured skin (textured meshes) of 200 human subjects. We manually annotated locations that appeared to the human eye to contain a pigmented skin lesion as well as tracked a subset of lesions occurring on the same subject imaged in different poses. Our results, when compared to three human annotators, suggest that the trained Faster R-CNN detects lesions at a similar performance level as the human annotators. Our lesion tracking algorithm achieves an average matching accuracy of 88% on a set of detected corresponding pairs of prominent lesions of subjects imaged in different poses, and an average longitudinal accuracy of 71% when encompassing additional errors due to lesion detection. As there currently is no other large-scale publicly available dataset of 3D total-body skin lesions, we publicly release over 25,000 3DBodyTex manual annotations, which we hope will further research on total-body skin lesion analysis.     

Aqueous outflow channels and its lymphatic association: A review

The human eye has a unique immune architecture and behavior. While the conjunctiva is known to have a well-defined lymphatic drainage system, the cornea, sclera, and uveal tissues were historically considered “alymphatic” and thought to be immune privileged. The very fact that the aqueous outflow channels carry a clear fluid (aqueous humor) along the outflow pathway makes it hard to ignore its lymphatic-like characteristics. The development of novel lymphatic lineage markers and expression of these markers in aqueous outflow channels and improved imaging capabilities has sparked a renewed interest in the study of ocular lymphatics. Ophthalmic lymphatic research has had a directional shift over the last decade, offering an exciting new physiological platform that needs further in-depth understanding. The evidence of a presence of distinct lymphatic channels in the human ciliary body is gaining significant traction. The uveolymphatic pathway is an alternative new route for aqueous outflow and adds a new dimension to pathophysiology and management of glaucoma. Developing novel animal models, markers, and non-invasive imaging tools to delineate the core anatomical structure and physiological functions may help pave some crucial pathways to understand disease pathophysiology and help develop novel targeted therapeutic approaches for glaucoma.     

Directional-TV algorithm for image reconstruction from limited-angular-range data

Investigation of image reconstruction from data collected over a limited-angular range in X-ray CT remains a topic of active research because it may yield insight into the development of imaging workflow of practical significance. This reconstruction problem is well-known to be challenging, however, because it is highly ill-conditioned. In the work, we investigate optimization-based image reconstruction from data acquired over a limited-angular range that is considerably smaller than the angular range in short-scan CT. We first formulate the reconstruction problem as a convex optimization program with directional total-variation (TV) constraints applied to the image, and then develop an iterative algorithm, referred to as the directional-TV (DTV) algorithm for image reconstruction through solving the optimization program. We use the DTV algorithm to reconstruct images from data collected over a variety of limited-angular ranges for breast and bar phantoms of clinical- and industrial-application relevance. The study demonstrates that the DTV algorithm accurately recovers the phantoms from data generated over a significantly reduced angular range, and that it considerably diminishes artifacts observed otherwise in reconstructions of existing algorithms. We have also obtained empirical conditions on minimal-angular ranges sufficient for numerically accurate image reconstruction with the DTV algorithm.     

A comprehensive method for calculating total body irradiation

PurposeTo provide means for calculating the dose received by various tissues of the patient, calculate lung shield, and verify received dose using a phantom as a tool for quality assurance for a planned Total Body Irradiation (TBI) procedure in radiotherapy.MethodUsing Microsoft Visual Basic, MATLAB, and Python, a program for Total Body Irradiation Calculation in Radiotherapy (TBICR) is constructed. It uses patient translation and beam zone method for total body irradiation calculations to compute the proper dose received by the patient and determine the lung shield thickness. There are three main user-friendly interfaces in the application. The first one allows the user to upload the TBI topography and estimate the distances needed for TBI calculations. The second one enables the user to count the number of beam zones needed for each point and estimate the effective area (A_eff) for each level. The third interface estimates the velocity required to deliver the relative dose depending on patient separation, Monitor Units (MU), couch speed and travel distance. It allows the user to compute the required lung shield thickness, read any patient's CT DICOM file and acquire dose in any distinct location using machine learning model to predict the dose.ResultsThe TBICR software has been successfully validated by reproducing all of the manual calculations in an exact and timely manner. TBICR generated more accurate results and confirmed the absorbed dose to patient through measurements on Anderson phantom.ConclusionsA computer program for the calculation of total body irradiation (TBI) is described in full. The dose received at each point on the patient, the calculation of lung shield and the determination of the velocity and time required for the couch movement are all made possible using the software. The ease of use, precision, data storage and printing are some important features of the present software.     

Patient engagement in the Continuing Professional Development programs within the department of radiation oncology at the University of Toronto (UTDRO): A qualitative study

IntroductionThere is little research regarding patient engagement (PE) in Continuing Professional Development (CPD) programs in radiation oncology. This study aims to understand the barriers and enablers to PE in the design and implementation process of CPD programs, and advance PE in these programs moving forward.MethodsThis qualitative study involved 17 semi-structured interviews, with 5 cancer patients and 12 educators, conducted from June 2019 to April 2020. Interview data identified common themes, such as: the current state of PE in CPD programming, and key barriers and recommendations on how to engage patients in meaningful and practical ways.ResultsSix themes were identified related to PE: the concept of PE, ethical considerations, barriers, key considerations in planning resources, and the anticipated impact of PE on curriculum planning.ConclusionBoth patients and educators emphasized that creating and sustaining meaningful educator-patient relationships and giving patients an active and effective role in CPD planning would improve curriculum content. The University of Toronto Department of Radiation Oncology (UTDRO) should consider building this initiative into its strategic CPD priorities and ensure the appropriate infrastructure is in place.     

Vascular and Chronological Age in Subjects with Erectile Dysfunction: A Cross-Sectional Study

IntroductionVascular age, as derived from the SCORE project algorithm for cardiovascular (CV) risk estimation, is an effective way for communicating CV risk. However, studies on its clinical correlates are scanty.AimTo evaluate if the difference between vascular and chronological age (Δage), in a population of subjects with erectile dysfunction (ED), can identify men with a worse risk profile.MethodsA consecutive series of 2,853 male patients attending the outpatient clinic for erectile dysfunction (ED) for the first time was retrospectively studied. Among them, 85.4% (n = 2,437) were free of previous MACE and were analyzed.Main Outcome MeasuresSeveral clinical, biochemical, and penile color Doppler parameters were studied. Vascular age was derived from the SCORE project algorithm, and the Δage was considered.ResultsHigher Δage is associated with several conventional (family history of CV diseases, hyperglycemia, elevated triglycerides, and increased prevalence of metabolic syndrome) and unconventional (severity of ED, frequency of sexual activity, alcohol abuse, lower education level, fatherhood, extramarital affairs, compensated hypogonadism, and low prolactin levels) risk factors. Δage is inversely related to penile color Doppler parameters, including flaccid and dynamic peak systolic velocity and flaccid acceleration (β = −0.125, −0.113, and −0.134, respectively, all P < 0.0001).ConclusionsIn subjects referring for ED without a personal history of CV events, Δage is associated with an adverse cardio-metabolic profile and worse penile color Doppler ultrasound parameters. Δage provides a simple method for identifying high-risk men that must undergo significant modification in their lifestyle and risk factors. In addition, it can be considered a simple, inexpensive, and safe surrogate marker of penile arterial damage.