Survey of the publics' preferences for communication of medical radiation risk

To comply with the Ionising Radiations (Medical Exposures) Regulations 2017, patients need to be adequately informed of medical radiation risks prior to exposure. This study used a survey developed in partnership with patients and members of the public to explore patient preferences for radiation risk communication. It was distributed through social media between 28/4/2020 and 18/7/2020. All respondents (N = 376) wanted to be informed about radiation risk, though the threshold at which they wished to be informed varied. The current practice of displaying posters in waiting areas does not meet the expressed preference of the patients if used in isolation. Only 6% of respondents were satisfied with the commonly used statement that the 'risk is low' if used in isolation. The majority of respondents (73%) said they would not be concerned about an increase in the risk of cancer of less than 1 in 10 000. The level of risk at which patients express a concern and the methodology for risk communication has been evaluated and based on these findings, and pre-existing literature, a graded approach to radiation risk communication based on modality is proposed. Patients must be involved throughout the evolution of this practice

Assessment of an ultrasound bladder scanner in prostate radiotherapy: A validation study and analysis of bladder filling variability

IntroductionDuring prostate radiotherapy treatment, it is important to ensure the position of the bladder and prostate is consistent between treatments. The aim of this study was to provide a quantitative basis for incorporating ultrasound bladder volume estimates into local practice for prostate radiotherapy.MethodsAgreement between bladder volume estimates obtained using computed tomography (CT) and ultrasound was assessed. Analysis of bladder volumes between planning and treatment scans was used to quantify expected variations in bladder volume over the course of radiotherapy. Dose–volume statistics were estimated and compared to planned dose constraints to propose a target bladder volume and tolerance.ResultsBladder volume measurements were obtained from 19 radiotherapy patients using ultrasound and CT. Ultrasound underestimated bladder volume compared to CT with a mean bias of –28 ± 30 ml. Pre-treatment (planning) bladder volumes varied from 71 to 383 ml with a mean of 200 ml. Treatment bladder volumes reduced by more than half in 9% of patients during the course of their treatment, potentially leading to a 30% increase in mean bladder dose. Patients with pre-treatment bladder volumes ConclusionsA pragmatic individualised drinking protocol, aimed at achieving a minimum ultrasound bladder volume of 200 ml at planning CT, may be beneficial to reproducibility in radiotherapy treatment. Ultrasound measurements prior to treatment should ideally confirm that bladder volume is at least half the volume measured at planning.</div

Magnetic resonance imaging of the pulsing brain: a systematic review

Objective: To perform a systematic review of the literature exploring magnetic resonance imaging (MRI) methods for measuring natural brain tissue pulsations (BTPs) in humans. Methods: A prospective systematic search of MEDLINE, SCOPUS and OpenGrey databases was conducted by two independent reviewers using a pre-determined strategy. The search focused on identifying reported measurements of naturally occurring BTP motion in humans. Studies involving non-human participants, MRI in combination with other modalities, MRI during invasive procedures and MRI studies involving externally applied tests were excluded. Data from the retrieved records were combined to create Forest plots comparing brain tissue displacement between Chiari-malformation type 1 (CM-I) patients and healthy controls using an independent samples t-test. Results: The search retrieved 22 eligible articles. Articles described 5 main MRI techniques for visualisation or quantification of intrinsic brain motion. MRI techniques generally agreed that the amplitude of BTPs varies regionally from 0.04 mm to ~ 0.80 mm, with larger tissue displacements occurring closer to the centre and base of the brain compared to peripheral regions. Studies of brain pathology using MRI BTP measurements are currently limited to tumour characterisation, idiopathic intracranial hypertension (IIH), and CM-I. A pooled analysis confirmed that displacement of tissue in the cerebellar tonsillar region of CM-I patients was + 0.31 mm [95% CI 0.23, 0.38, p </p

Brain tissue pulsation in healthy volunteers

It is well known that the brain pulses with each cardiac cycle, but interest in measuring cardiac-induced brain tissue pulsations (BTPs) is relatively recent. This study was aimed at generating BTP reference data from healthy patients for future clinical comparisons and modelling. BTPs were measured through the forehead and temporal positions as a function of age, sex, heart rate, mean arterial pressure and pulse pressure. A multivariate regression model was developed based on transcranial tissue Doppler BTP measurements from 107 healthy adults (56 male) aged from 20–81 y. A subset of 5 participants (aged 20–49 y) underwent a brain magnetic resonance imaging scan to relate the position of the ultrasound beam to anatomy. BTP amplitudes were found to vary widely between patients (from ∼4 to ∼150 µm) and were strongly associated with pulse pressure. Comparison with magnetic resonance images confirmed regional variations in BTP with depth and probe position.<br