A structure-based gamma evaluation method for identifying clinically relevant dose differences in organs at risk.

Gamma evaluation is currently the most widely used dose comparison method for patient specific quality assurance (PSQA). However, existing methods for normalising the dose difference, using either the dose at the global maximum dose point or at each local point, can respectively lead to under- and over-sensitivity to dose differences in organ-at-risk structures. This may be of concern for plan evaluation from clinical perspectives.

Fluoroscopically guided vascular and cardiac transcatheter procedures: a comparison of occupational and patient dose by anatomical region.

X-ray guided procedures are being performed by an increasing variety of medical specialties. Due to improvements in vascular transcatheter therapies, there is an increasing overlap of imaged anatomy between medical specialties. There is concern that non-radiology fluoroscopic operators may not have sufficient training to be well informed of the potential implications of radiation exposure and mitigation strategies to reduce dose.

A comparison of patient dose and occupational eye dose to the operator and nursing staff during transcatheter cardiac and endovascular procedures.

The number and complexity of transcatheter procedures continue to increase, raising concerns regarding radiation exposure to patients and staff. Procedures such as transaortic valve implantations (TAVI) have led to cardiologists adopting higher dose techniques, such as digital subtraction angiography (DSA). This study compared the estimated patient and occupational eye dose during coronary angiography (CA), percutaneous coronary intervention (PCI), TAVI workups (TWU), TAVI, endovascular aneurysm repairs (EVAR), and other peripheral diagnostic (VD) and interventional (VI) vascular procedures.

A publicly available dataset of out-of-field dose profiles of a 6 MV linear accelerator.

An increase in radiotherapy-induced secondary malignancies has led to recent developments in analytical modelling of out-of-field dose. These models must be validated against measurements, but currently available datasets are outdated or limited in scope. This study aimed to address these shortcomings by producing a large dataset of out-of-field dose profiles measured with modern equipment.

Impact of dose reducing software on patient and staff temple dose during fluoroscopically guided pacemaker insertion, closure devices implantation and coronary angiography procedures.

The aim of this study is to investigate the effectiveness of dose reducing software (ClarityIQ) on patient and staff dose during fluoroscopically guided cardiac procedures. Dose measurements were collected in a room without dose reducing software (n = 157) and compared with similar procedures performed in two rooms with the software (n = 1141). Procedures included diagnostic coronary angiography, percutaneous coronary intervention, deployment of cardiac closure devices (for occlusion of atrial septal defect, patent foramen ovale, and atrial appendage) and insertion of permanent pacemakers.

Radiation dose to nurses, cardiologists, and patients during coronary angiography: a comparison of femoral and radial access.

Background: Exposure to radiation during fluoroscopically guided cardiac procedures is a cause for concern for both the patient and staff.

Aims: This study sought to compare the occupational and patient radiation dose during femoral and radially accessed invasive coronary angiography (CA).

Methods And Results: Occupational dose (µSv) was measured at the left temple of the cardiologist (n = 17), scrub (n = 27), and circulator nurse (n = 27) during 761 femoral and 671 radially accessed diagnostic coronary angiograms and percutaneous coronary intervention (PCI) procedures.

Comparison of patient and staff temple dose during fluoroscopically guided coronary angiography, implantable cardiac devices, and electrophysiology procedures.

There is a paucity of literature comparing patient and staff dose during coronary angiography (CA), implantable cardiac devices, permanent pacemakers (PPM) and electrophysiology (EP) procedures and little noting dose to staff other than cardiologists. This study sought to compare patient and occupational dose during a range of fluoroscopically guided cardiac procedures. Radiation dose levels for the patients (n = 1651), cardiologists (n = 24), scrub (n = 32) and scout nurses (n = 35) were measured in a prospective single-centre study between February 2017 and August 2019.

Use oftransit portal images to detect gross inter-fraction patient geometry changes on an O-ring type linear accelerator for pelvis and head/neck patients.

The purpose of this work was to investigate the use of the Varian Portal Dosimetry application in conjunction withmegavoltage portal images on a Varian Halcyon O-ring type linear accelerator as andosimetry constancy (IVDc) tool for pelvis and head/neck patients receiving VMAT treatments. Sensitivity testing was conducted on phantoms with varying thicknesses (0.2 cm-1.

Occupational and Patient Radiation Dose and Quality Implications of Femoral Access Imaging During Coronary Angiography.

Purpose: Cardiologists often perform angiography of the common femoral artery (CFA) access site to evaluate whether the anatomy is suitable for deployment of a vascular closure device or to assess whether iatrogenic vessel damage has occurred. The choice of acquisition mode has radiation dose implications. The objective of this study was to investigate the influence of the selected type of CFA x-ray imaging mode (fluoro save, cine acquisition and digital subtraction angiography (DSA)) and tube angle on patient and staff dose during coronary angiography.

Modelling of a novel technique to improve the visualisation of implanted fiducial markers for intra-fraction MV imaging of prostate VMAT targets.

. This study explored a novel technique to improve the MV imaging based fiducial visibility for a cohort of prostate radiotherapy patients, without compromising the original treatment plan. The study also compared these results to visibility using single MLC control points, as well as short arcs.

The suitability of smartphone camera sensors for detecting radiation.

The advanced image sensors installed on now-ubiquitous smartphones can be used to detect ionising radiation in addition to visible light. Radiation incidents on a smartphone camera's Complementary Metal Oxide Semiconductor (CMOS) sensor creates a signal which can be isolated from a visible light signal to turn the smartphone into a radiation detector. This work aims to report a detailed investigation of a well-reviewed smartphone application for radiation dosimetry that is available for popular smartphone devices under a calibration protocol that is typically used for the commercial calibration of radiation detectors.

Dosimetric evaluation of a patient-specific 3D-printed oral positioning stent for head-and-neck radiotherapy.

As head-and-neck radiotherapy treatments become more complex and sophisticated, and the need to control and stabilise the positioning of intra-oral anatomy becomes more important, leading the increasing use of oral positioning stents during head-and-neck radiotherapy simulation and delivery. As an alternative to the established practice of creating oral positioning stents using wax, this study investigated the use of a 3D printing technique. An Ender 5 3D printer (Creality 3D, Shenzhen, China) was used, with PLA+ "food-safe" polylactic acid filament (3D Fillies, Dandenong South, Australia), to produce a low-density 3D printed duplicate of a conventional wax stent.

Measuring foetal dose from tomotherapy treatments.

Treating pregnant women in the radiotherapy clinic is a rare occurrence. When it does occur, it is vital that the dose received by the developing embryo or foetus is understood as fully as possible. This study presents the first investigation of foetal doses delivered during helical tomotherapy treatments.

Comparison of global and local gamma evaluation results using isodose levels.

The aim of this study is to evaluate the behaviour of global and local gamma analyses with isodose levels. Global and local gamma evaluation were performed on patient-specific quality assurance (PSQA) data from 100 volumetric modulated arc therapy (VMAT) arcs and 100 helical tomotherapy (HT) plans, using an in-house gamma code. Gamma pass rates versus isodose levels were plotted and evaluated.

Exploring the gamma surface: A new method for visualising modulated radiotherapy quality assurance results.

Purpose: This work presents a novel method of visualising the results of patient-specific quality assurance (QA) for modulated radiotherapy treatment plans, using a three-dimensional distribution of gamma pass rates, referred to as the "gamma surface". The method was developed to aid in comparing borderline and failing QA plans, and to better compare patient-specific QA results between departments.

Methods: Gamma surface plots were created for a representative sample of situations encountered during patient-specific QA.

Taller staff occupationally exposed to less radiation to the temple in cardiac procedures, but risk higher doses during vascular cases.

This study aimed to evaluate the effect of nurse and doctor height on occupational dose to the temple during fluoroscopically guided cardiovascular procedures. Additionally, an evaluation of the relationship between doctor height and table height was performed. Staff exposed during fluoroscopic procedures may be at elevated risk of cardiovascular damage or oncogenesis and have demonstrated a higher incidence of subscapular cataracts.

The new Scopus CiteScore formula and the Journal Impact Factor: a look at top ranking journals and middle ranking journals in the Scopus categories of General Physics and Astronomy, Materials Science, General Medicine and Social Sciences.

In June 2020 Elsevier announced that the CiteScore metric of journals underwent a change. This work examines the effect of these changes for 40 journals, chosen from the top five and middle five (ranked by CiteScore) journals in the subject areas of General Physics and Astronomy, Materials Science, Medicine, Social Sciences) and compares to the Journal Impact Factor. It is shown that in the data studied here, the new methodology is less susceptible to influence of the proportion of editorial material in a journal, but tends to favour journals in research fields that publish articles which get cited more quickly.

A review of stereotactic body radiotherapy for the spine.

Radiation therapy of the spine, as recourse for spinal tumours, is an effective method of achieving pain reduction and local control. Hypofractionated techniques like stereotactic body radiation therapy and especially stereotactic radiosurgery are quickly becoming more popular as studies are published demonstrating their superior outcomes. This review concerns aspects of spinal radiotherapy of interest to the clinical medical physicist, with a focus on stereotactic techniques.

Characteristics of inverse gamma histograms.

This work explores the characteristics of the inverse gamma histogram and its potential use as part of the patient specific quality assurance (PSQA) program for volumetric modulated arc therapy (VMAT). ArcCheck measured dose files and TPS predicted dose files were imported and analysed using the in-house inverse gamma code developed in the Python package. Inverse gamma with fixed distance-to-agreement of 2 mm were calculated for 23 VMAT arcs.

Investigating the use of aperture shape controller in VMAT treatment deliveries.

Background: Aperture shape controller (ASC) is a recently introduced leaf sequencer that controls the complexity of multileaf collimator apertures in the Photon Optimizer algorithm of the Eclipse treatment planning system. The aim of this study is to determine if the ASC can reduce plan complexity and improve verification results, without compromising plan quality.

Methods: Thirteen plans grouped into cohorts of head and neck/brain, breast/chest and pelvis were reoptimised using the same optimization as the non-ASC setting for low, moderate and high ASC settings.