Experiences of UK clinical scientists (Physical Sciences modality) with their regulator, the Health and Care Professions Council: results of a 2022 survey.

BACKGROUND: In healthcare, regulation of professions is an important tool to protect the public. With increasing regulation however, professions find themselves under increasing scrutiny. Recently there has also been considerable concern with regulator performance, with high profile reports pointing to cases of inefficiency and bias. Whilst reports have often focused on large staff groups, such as doctors, in the literature there is a dearth of data on the experiences of smaller professional groups such Clinical Scientists with their regulator, the Health and Care Professions Council. This article reports the findings of a survey from Clinical Scientists (Physical Sciences modality) about their experiences with their regulator, and their perception of the quality and safety of that regulation. METHODS: Between July-October 2022, a survey was conducted via the Medical Physics and Engineering mail-base, open to all medical physicists & engineers. Questions covered typical topics of registration, communication, audit and fitness to practice. The questionnaire consisted of open and closed questions. Likert scoring, and thematic analysis were used to assess the quantitative and qualitative data. RESULTS: Of 146 responses recorded, analysis was based on 143 respondents. Overall survey sentiment was significantly more negative than positive, in terms of regulator performance (negative responses 159; positive 106; significant at p < 0.001). Continuous Professional Development audit was rated median 4; other topics were rated as neutral (fitness to practice, policies & procedures); and some as poor (value). CONCLUSIONS: The Clinical Scientist (Physical Sciences) professional registrants rated the performance of their regulator more negatively than other reported assessments (by the Professional Standards Authority). Survey respondents suggested a variety of performance aspects, such as communication and fitness to practice, would benefit from improvement. Indications from this small dataset, suggest a larger survey of HCPC registrants would be useful.

Acoustic Noise and Magnetic Resonance Imaging: A Narrative/Descriptive Review.

Magnetic resonance imaging generates unwanted acoustic noise. This review describes the work characterizing the acoustic noise, and the various solutions to control and attenuate the acoustic noise. There are also discussions about the permissible limits, and guidance regarding acoustic noise exposure for staff, patients, and volunteers. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 1.

Feasibility of image registration and intensity-modulated radiotherapy planning with hyperpolarized helium-3 magnetic resonance imaging for non-small-cell lung cancer.

PURPOSE: To demonstrate the feasibility of registering hyperpolarized helium-3 magnetic resonance images ((3)He-MRI) to X-ray computed tomography (CT) for functionally weighted intensity-modulated radiotherapy (IMRT) planning. METHODS AND MATERIALS: Six patients with non-small-cell lung cancer underwent (3)He ventilation MRI, which was fused with radiotherapy planning CT using rigid registration. Registration accuracy was assessed using an overlap coefficient, calculated as the proportion of the segmented (3)He-MR volume (V(MRI)) that intersects the segmented CT lung volume expressed as a percentage of V(MRI). For each patient, an IMRT plan that minimized the volume of total lung receiving a dose > or = 20 Gy (V(20)) was compared with a plan that minimized the V(20) to well-ventilated lung defined by the registered (3)He-MRI. RESULTS: The (3)He-MRI and CT were registered with sufficient accuracy to enable functionally guided IMRT planning (median overlap, 89%; range, 72-97%). In comparison with the total lung IMRT plans, IMRT constrained with (3)He-MRI reduced the V(20) not only for the well-ventilated lung (median reduction, 3.1%; range, 0.4-5.1%; p = 0.028) but also for the total lung volume (median reduction, 1.6%; range, 0.2-3.7%; p = 0.028). CONCLUSIONS: Statistically significant improvements to IMRT plans are possible using functional information provided by (3)He-MRI that has been registered to radiotherapy planning CT.

An assessment of cone beam CT in the adaptive radiotherapy planning process for non-small-cell lung cancer patients.

OBJECTIVE: To investigate the potential use of cone beam CT (CBCT) in adaptive radiotherapy (ART) planning process for non-small-cell lung cancer (NSCLC). METHODS: 17 retrospective patients with NSCLC Stage T1-T4, who had completed a course of radiotherapy with weekly CBCT imaging were selected for the study. The patients had been delineated and planned for three-dimensional (3D) conformal treatment (prescription: 55 Gy in 20 fractions) based on free-breathing four-dimensional CT data. Of these initial 17 patients, 12 had full quantitative data on gross tumour volume (GTV) position and volume throughout treatment. GTV delineation was carried out on weekly CBCT by a clinical oncologist. For each patient, mean percentage change in GTV and centre of mass (COM) displacement (based on 3D vectors) were calculated throughout treatment. Volume overlap between GTVs was calculated. Correlation of the COM displacement and planning GTV (pGTV) was assessed. A linear mixed model with patients as random effects was fitted to the data to assess potential benefit from using ART for these patients. RESULTS: Comparison of CBCT-based GTV acquired prior to Fraction 1 (cbctGTV1) to pGTV showed mean 20 ± 19% volume increase using a related sample Wilcoxon signed rank test p = 0.04. Correlation was identified between volume reductions and dose delivered (beta = -0.003, p < 0.001)-a highly statistically significant association. Compared with cbctGTV1, the mean ratios ± standard deviation were cbctGTV2, 0.93 ± 0.08; cbctGTV3, 0.84 ± 0.12; and cbctGTV4, 0.75 ± 0.14. The dice similarity coefficient was 0.81 ± 0.14, 0.78 ± 0.17, 0.73 ± 0.19, respectively. The COM was consistent throughout treatment (mean 0.35 ± 0.24 cm). A fitted model predicts that a mean change of 30% volume relative to cbctGTV1 occurs at a dose of approximately 50 Gy. CONCLUSION: Using a 30% reduction in volume, ART would not be of benefit for all radiotherapy-alone-treated patients with NSCLC assessed in this study. For individual patients and patients with atelectasis, CBCT imaging was able to identify volume change. ADVANCES IN KNOWLEDGE: For patients treated with 55 Gy in 20 fractions, target volume changes throughout treatment have been demonstrated using CBCT and can be used to highlight patients who may benefit from ART.

Stereotactic ablative body radiotherapy for non-small-cell lung cancer: setup reproducibility with novel arms-down immobilization.

OBJECTIVE: A clinical evaluation of the intrafraction and interfraction setup accuracy of a novel thermoplastic mould immobilization device and patient position in early-stage lung cancer being treated with stereotactic radiotherapy at the Beatson West of Scotland Cancer Centre, Glasgow, UK. METHODS: 35 patients were immobilized in a novel, arms-down position, with a four-point Klarity™ (Klarity Medical Products, Ohio, US) clear thermoplastic mould fixed to a SinMed (CIVCO Medical solutions, lowa, US) head and neck board. A knee support was also used for patient comfort and support. Pre- and post-treatment kilovoltage cone beam CT (CBCT) images were fused with the planning CT scan to determine intra- and interfraction motion. A total of 175 CBCT scans were analysed in the longitudinal, vertical and lateral directions. RESULTS: The mean intrafraction errors were 0.05 ± 0.77 mm (lateral), 0.44 ± 1.2 mm (superior-inferior) and -1.44 ± 1.35 mm (anteroposterior), respectively. Mean composite three-dimensional displacement vector was 2.14 ± 1.2 mm. Interfraction errors were -0.66 ± 2.35 mm (lateral), -0.13 ± 3.11 mm (superior-inferior) and 0.00 ± 2.94 mm (anteroposterior), with three-dimensional vector 4.08 ± 2.73 mm. CONCLUSION: Setup accuracy for lung image-guided stereotactic ablative radiotherapy using a unique immobilization device, where patients have arms by their sides, has been shown to be safe and favourably comparable to other published setup data where more complex and cumbersome devices were utilised. There was no arm toxicity reported and low arm doses. Advances in knowledge: We report on the accuracy of a novel patient immobilization device.

An assessment of the efficiency of methods for measurement of the computed tomography dose index (CTDI) for cone beam (CBCT) dosimetry by Monte Carlo simulation.

The IEC has introduced a practical approach to overcome shortcomings of the CTDI100 for measurements on wide beams employed for cone beam (CBCT) scans. This study evaluated the efficiency of this approach (CTDIIEC) for different arrangements using Monte Carlo simulation techniques, and compared CTDIIEC to the efficiency of CTDI100 for CBCT. Monte Carlo EGSnrc/BEAMnrc and EGSnrc/DOSXYZnrc codes were used to simulate the kV imaging system mounted on a Varian TrueBeam linear accelerator. The Monte Carlo model was benchmarked against experimental measurements and good agreement shown. Standard PMMA head and body phantoms with lengths 150, 600, and 900 mm were simulated. Beam widths studied ranged from 20-300 mm, and four scanning protocols using two acquisition modes were utilized. The efficiency values were calculated at the centre (εc) and periphery (εp) of the phantoms and for the weighted CTDI (εw). The efficiency values for CTDI100 were approximately constant for beam widths 20-40 mm, where εc(CTDI100), εp(CTDI100), and εw(CTDI100) were 74.7 ± 0.6%, 84.6 ± 0.3%, and 80.9 ± 0.4%, for the head phantom and 59.7 ± 0.3%, 82.1 ± 0.3%, and 74.9 ± 0.3%, for the body phantom, respectively. When beam width increased beyond 40 mm, ε(CTDI100) values fell steadily reaching ~30% at a beam width of 300 mm. In contrast, the efficiency of the CTDIIEC was approximately constant over all beam widths, demonstrating its suitability for assessment of CBCT. εc(CTDIIEC), εp(CTDIIEC), and εw(CTDIIEC) were 76.1 ± 0.9%, 85.9 ± 1.0%, and 82.2 ± 0.9% for the head phantom and 60.6 ± 0.7%, 82.8 ± 0.8%, and 75.8 ± 0.7%, for the body phantom, respectively, within 2% of ε(CTDI100) values for narrower beam widths. CTDI100,w and CTDIIEC,w underestimate CTDI∞,w by ~55% and ~18% for the head phantom and by ~56% and ~24% for the body phantom, respectively, using a clinical beam width 198 mm. The CTDIIEC approach addresses the dependency of efficiency on beam width successfully and correction factors have been derived to allow calculation of CTDI∞.

The influence of MRI scan position on patients with oropharyngeal cancer undergoing radical radiotherapy.

BACKGROUND: The purpose of this study was to demonstrate how magnetic resonance imaging (MRI) patient position protocols influence registration quality in patients with oropharyngeal cancer undergoing radical radiotherapy and the consequences for gross tumour volume (GTV) definition and radiotherapy planning. METHODS AND MATERIALS: Twenty-two oropharyngeal patients underwent a computed tomography (CT), a diagnostic MRI (MRI(D)) and an MRI in the radiotherapy position within an immobilization mask (MRI(RT)). Clinicians delineated the GTV on the CT viewing the MRI(D) separately (GTV(C)); on the CT registered to MRI(D) (GTV(D)) and on the CT registered to MRI(RT) (GTV(RT)). Planning target volumes (PTVs) were denoted similarly. Registration quality was assessed by measuring disparity between structures in the three set-ups. Volumetric modulated arc therapy (VMAT) radiotherapy planning was performed for PTV(C), PTV(D) and PTV(RT). To determine the dose received by the reference PTV(RT), we optimized for PTV(C) and PTV(D) while calculating the dose to PTV(RT). Statistical significance was determined using the two-tailed Mann-Whitney or two-tailed paired student t-tests. RESULTS: A significant improvement in registration accuracy was found between CT and MRI(RT) versus the MRI(D) measuring distances from the centre of structures (geometric mean error of 2.2 mm versus 6.6 mm). The mean GTV(C) (44.1 cm3) was significantly larger than GTV(D) (33.7 cm3, p value = 0.027) or GTV(RT) (30.5 cm3, p value = 0.014). When optimizing the VMAT plans for PTV(C) and investigating the mean dose to PTV(RT) neither the dose to 99% (58.8%) nor 95% of the PTV (84.7%) were found to meet the required clinical dose constraints of 90% and 95% respectively. Similarly, when optimizing for PTV(D) the mean dose to PTV(RT) did not meet clinical dose constraints for 99% (14.9%) nor 95% of the PTV (66.2%). Only by optimizing for PTV(RT) were all clinical dose constraints achieved. CONCLUSIONS: When oropharyngeal patients MRI scans are performed in the radiotherapy position there are significant improvements in CT-MR image registration, target definition and PTV dose coverage.