The effect of intra- and inter-fractional motion on target coverage and margins in proton therapy for uveal melanoma.

This study aims to assess the effective lateral margin requirements for target coverage in ocular proton therapy (OPT), considering the unique challenges posed by eye motion and hypofractionation. It specifically addresses the previously unaccounted-for uncertainty contribution of intra-fractional motion, in conjunction with setup uncertainties, on dosimetric determination of lateral margin requirements.The methodology integrates dose calculations from the in-house developed treatment planning system OCULARIS with measured intra-fractional motion, patient models from EyePlan and Monte Carlo (MC) sampling of setup uncertainties.

Multi-camera optical tracking and fringe pattern analysis for eye surface profilometry in ocular proton therapy.

Background And Purpose: An optical tracking system for high-precision measurement of eye position and orientation during proton irradiation of intraocular tumors was designed. The system performed three-dimensional (3D) topography of the anterior eye segment using fringe pattern analysis based on Fourier Transform Method (FTM).

Materials And Methods: The system consisted of four optical cameras and two projectors.

MRI and FUNDUS image fusion for improved ocular biometry in Ocular Proton Therapy.

Introduction: Ocular biometry in Ocular Proton Therapy (OPT) currently relies on a generic geometrical eye model built by referencing surgically implanted markers. An alternative approach based on image fusion of volumetric Magnetic Resonance Imaging (MRI) and panoramic fundus photography was investigated.

Materials And Methods: Eighteen non-consecutive uveal melanoma (UM) patients, who consented for an MRI and had their tumour base visible on panoramic fundus photography, were included in this comparative analysis.

Non-invasive recognition of eye torsion through optical imaging of the iris pattern in ocular proton therapy.

The introduction of non-invasive imaging techniques such as MRI imaging for treatment planning and optical eye tracking for in-room eye localization would obviate the requirement of clips implantation for many patients undergoing ocular proton therapy. This study specifically addresses the issue of torsional eye movement detection during patient positioning. Non-invasive detection of eye torsion is performed by measuring the iris pattern rotations using a beams eye view optical camera.

Development and validation of a new set-up simulator dedicated to ocular proton therapy at CNAO.

An Eye Tracking System (ETS) is used at CNAO for providing a stable and reproducible ocular proton therapy (OPT) set-up, featuring a fixation light (FL) and monitoring stereo-cameras embedded in a rigid case. The aim of this work is to propose an ETS set-up simulation algorithm, that automatically provides the FL positioning in space, according to patient-specific gaze direction and avoiding interferences with patient, beam and collimator. Two configurations are provided: one in the CT room for acquiring images required for treatment planning with the patient lying on a couch, and one related to the treatment room with the patient sitting in front of the beam.

Commissioning and quality assurance of a novel solution for respiratory-gated PBS proton therapy based on optical tracking of surface markers.

We present the commissioning and quality assurance of our clinical protocol for respiratory gating in pencil beam scanning proton therapy for cancer patients with moving targets. In a novel approach, optical tracking has been integrated in the therapy workflow and used to monitor respiratory motion from multiple surrogates, applied on the patients' chest. The gating system was tested under a variety of experimental conditions, specific to proton therapy, to evaluate reaction time and reproducibility of dose delivery control.

Technical Note: Benchmarking automated eye tracking and human detection for motion monitoring in ocular proton therapy.

Purpose: Ocular proton therapy is an effective therapeutic option for patients affected with uveal melanomas. An optical eye-tracking system (ETS) aiming at noninvasive motion monitoring was developed and tested in a clinical scenario.

Materials And Methods: The ETS estimates eye position and orientation at 25 frames per second using the three-dimensional position of pupil and cornea curvature centers identified, in the treatment room, through stereoscopic optical imaging and infrared eye illumination.

Time-resolved volumetric MRI in MRI-guided radiotherapy: an in silico comparative analysis.

MRI-treatment units enable 2D cine-MRI centred in the tumour for motion detection in radiotherapy, but they lack 3D information due to spatio-temporal limits. To derive time-resolved 3D information, different approaches have been proposed in the literature, but a rigorous comparison among these strategies has not yet been performed. The goal of this study is to quantitatively investigate five published strategies that derive time-resolved volumetric MRI in MRI-guided radiotherapy: Propagation, out-of-plane motion compensation, Fayad model, ROI-based model and Stemkens model.

A platform for patient positioning and motion monitoring in ocular proton therapy with a non-dedicated beamline.

Purpose: At Centro Nazionale di Adroterapia Oncologica (CNAO, Pavia, Italy) ocular proton therapy (OPT) is delivered using a non-dedicated beamline. This paper describes the novel clinical workflow as well as technologies and methods adopted to achieve accurate target positioning and verification during ocular proton therapy at CNAO.

Method: The OPT clinical protocol at CNAO prescribes a treatment simulation and a delivery phase, performed in the CT and treatment rooms, respectively.

Design and commissioning of the non-dedicated scanning proton beamline for ocular treatment at the synchrotron-based CNAO facility.

Purpose: Only few centers worldwide treat intraocular tumors with proton therapy, all of them with a dedicated beamline, except in one case in the USA. The Italian National Center for Oncological Hadrontherapy (CNAO) is a synchrotron-based hadrontherapy facility equipped with fixed beamlines and pencil beam scanning modality. Recently, a general-purpose horizontal proton beamline was adapted to treat also ocular diseases.

A ROI-based global motion model established on 4DCT and 2D cine-MRI data for MRI-guidance in radiation therapy.

In-room magnetic resonance imaging (MRI) allows the acquisition of fast 2D cine-MRI centered in the tumor for advanced motion management in radiotherapy. To achieve 3D information during treatment, patient-specific motion models can be considered the most viable solution. However, conventional global motion models are built using a single motion surrogate, independently from the anatomical location.

Noninvasive eye localization in ocular proton therapy through optical eye tracking: A proof of concept.

Purpose: Over the last four decades, Ocular Proton Therapy has been successfully used to treat patients affected by intraocular lesions. For this, treatment geometry verification is routinely performed using radiographic images to align a configuration of fiducial radiopaque markers implanted on the sclera outer surface. This paper describes the clinical application of an alternative approach based on optical eye tracking for three-dimensional noninvasive and automatic eye localization.

Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy.

Purpose: External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging.

The effect of two different faculty development interventions on third-year clerkship performance evaluations.

Background And Objectives: Clinical performance evaluations of medical students often fail to identify significant deficiencies. Many physicians are unwilling to give a poor or failing performance evaluation. Consequently, many clinical rotation grades are inflated and do not reflect actual student performance.

Medications for COPD: a review of effectiveness.

Chronic obstructive pulmonary disease (COPD) is a common problem among patients presenting to primary care. This condition has multiple individual and combined treatment regimens. The goals of treatment are to improve quality of life, exercise tolerance, sleep quality, and survival; and to reduce dyspnea, nocturnal symptoms, exacerbations, use of rescue medications, and hospitalizations.

Steroids ineffective for pain in children with pharyngitis.

In children with acute pharyngitis, oral dexamethasone does not provide clinically significant reductions in time to initial or complete pain relief. Reserve its use for children with group A beta-hemolytic streptococcus pharyngitis who have moderate to severe pain, realizing that the benefit is of questionable significance.

Suturing unnecessary for hand lacerations under 2 cm.

Hand lacerations less than 2 cm long without tendon, joint, fracture, or nerve complications and not involving the nail bed can be cleaned and dressed without suturing, with similar cosmetic results and time to resume normal activities. Moreover, managing these uncomplicated hand lacerations conservatively could result in better use of medical resources and improved patient satisfaction due to less pain and less time spent in the emergency department.