Recent Submissions

  • The role of 4-Dimensional flow in the assessment of bicuspid aortic valve and its valvulo-aortopathies

    Richards, Caryl; Parker, Alex; Alfuhied, Aseel; McCann, Gerry; Singh, Anvesha (2022-07)
    Bicuspid aortic valve is the most common congenital cardiac malformation and the leading cause of aortopathy and aortic stenosis in younger patients. Aortic wall remodelling secondary to altered haemodynamic flow patterns, changes in peak velocity, and wall shear stress may be implicated in the development of aortopathy in the presence of bicuspid aortic valve and dysfunction. Assessment of these parameters as potential predictors of disease severity and progression is thus desirable. The anatomic and functional information acquired from 4D flow MRI can allow simultaneous visualisation and quantification of the pathological geometric and haemodynamic changes of the aorta. We review the current clinical utility of haemodynamic quantities including velocity, wall sheer stress and energy losses, as well as visual descriptors such as vorticity and helicity, and flow direction in assessing the aortic valve and associated aortopathies.
  • Abemaciclib in patients with p16ink4A-deficient mesothelioma (MiST2): a single-arm, open-label, phase 2 trial

    Fennell, Dean; King, Amy; Anthony, Sarah; Poile, Charlotte; Scotland, Molly; Bhundia, Vina; Darlison, Liz; Dawson, Alan; Gaba, Aarti; Hutka, Margaret; et al. (2022)
    Background: Genetically stratified therapy for malignant mesothelioma is unavailable. Mesotheliomas frequently harbour loss of the chromosome 9p21.3 locus (CDKN2A-MTAP), which is associated with shorter overall survival due to loss of the tumour suppressor p16ink4A, an endogenous suppressor of cyclin-dependent kinase (CDK)4 and CDK6. Genetic restoration of p16ink4A suppresses mesothelioma in preclinical models, underpinning the rationale for targeting CDK4 and CDK6 in p16ink4A-negative mesothelioma. We developed a multicentre, stratified, phase 2 trial to test this hypothesis. Methods: The MiST2 study was a single-arm, open-label, phase 2 clinical trial done two UK centres. Patients older than 18 years with any histologically confirmed subtype of mesothelioma (pleural or peritoneal) with radiological progression after at least one course of platinum-based chemotherapy were molecularly screened by immunohistochemistry for p16ink4A. Patients with p16ink4A-negative mesothelioma were eligible for inclusion in the study. Patients were required to have measurable disease by modified Response Evaluation Criteria in Solid Tumours version 1.1 for malignant mesothelioma, a predicted life expectancy of at least 12 weeks, and an Eastern Cooperative Oncology Group performance status score of 0-1. Patients received oral abemaciclib 200 mg twice daily, administered in 28-day cycles for 24 weeks. The primary endpoint was the disease control rate (patients with complete responses, partial responses, or stable disease) at 12 weeks. The null hypothesis could be rejected if at least 11 patients had disease control. The efficacy and safety populations were defined as all patients who received at least one dose of the study drug. The study is registered with ClinicalTrials.gov, NCT03654833, and is ongoing (but MiST2 is now closed). Findings: Between Sept 31, 2019, and March 2, 2020, 27 eligible patients consented to molecular screening. The median follow-up was 18·4 weeks (IQR 6·7-23·9). One patient was excluded before treatment because of a serious adverse event before study drug allocation. 26 (100%) of 26 treated patients were p16ink4A deficient and received at least one dose of abemaciclib. Disease control at 12 weeks was reported in 14 (54%) of 26 patients (95% CI 36-71). Grade 3 or worse treatment-related adverse events (of any cause) occurred in eight (27%) of 26 patients (diarrhoea, dyspnoea, thrombocytopenia, vomiting, urinary tract infection, increased alanine aminotransferase, ascites, chest infection or suspected chest infection, neutropenic sepsis, alopecia, blood clot left calf, fall [broken neck and collar bone], haemoptysis, lower respiratory tract infection, and pulmonary embolism). Grade 3 or worse treatment-related adverse events occurred in three (12%) of 26 patients (diarrhoea, thrombocytopenia, vomiting, increased alanine aminotransferase, and pulmonary embolism). Serious adverse events occurred in six (23%) of 26 patients, leading to treatment discontinuation in one (4%) patient (diarrhoea, urinary tract infection, chest infection, neutropenic sepsis, fall [broken neck and collar bone], haemoptysis, lower respiratory tract infection, and pulmonary embolism). One patient had a serious adverse event related to abemaciclib (diarrhoea). One (4%) of 26 patients died from an adverse event (neutropenic sepsis). Interpretation: This study met its primary endpoint, showing promising clinical activity of abemaciclib in patients with p16ink4A-negative mesothelioma who were previously treated with chemotherapy, and warrants its further investigation in a randomised study as a targeted stratified therapy.
  • Incidence of synchronous contralateral tonsillar malignancy in a known case of unilateral tonsillar carcinoma

    Mahmood, Sara; Ahmed, Tauseef; Oladejo, Olaleye; Mair, Manish; Fagiry, Rihab; Hussain, Mohammed Hassan; Eltayeb, Mandy; Ahmad, Shoaib; Baker, Andrew; Vaidhyanth, Ram; et al.
    Objective: The literature is divided with regards to contralateral tonsillectomy in a known/suspected case of ipsilateral tonsillar malignancy. In this study, we evaluate the incidence of indolent synchronous contralateral tonsillar malignancy (SCTC) in patients with known ipsilateral tonsillar malignancy. Methods: All patients diagnosed with ipsilateral tonsillar carcinoma (TC) at a tertiary teaching center between January 2016 and December 2019 were screened. None of the patients were suspected to have bilateral TC. All patients underwent appropriate imaging in the form of Magnetic resonance imaging and computed tomography of head and neck region and then underwent bilateral tonsillectomy. The prevalence of bilateral tonsillar malignancy and the factors predicting them were analyzed. Results: In all 59 patients were included in the study. The mean and median age of the patient population was 60.8 and 59 years, respectively, with a male to female ratio of 3.2:1. The incidence of bilateral tonsillar malignancy in carcinoma of unknown primary (CUP) was 3/10 (33.3%). Among the remaining 49 patients, incidence of synchronous contralateral tonsillar carcinoma (SCTC) was 2/49 (4.08%). Overall, 5/59 (8.5%) patients had synchronous bilateral tonsillar malignancy. Furthermore, dysplasia was found in the contralateral tonsil in 4/10 (40%) CUP patients. Among the remaining 49 patients, dysplasia was seen in the contralateral tonsil in 20/49 (40.8%) patients. The absence of p16 expression predicted higher probability of SCTC. Factors like gender, T stage, nodal status or smoking did not predict SCTC. Conclusion: We recommend bilateral tonsillectomy in all patients with suspected or proven TC (unilateral or bilateral) and CUP as it helps identify indolent SCTC and it does not add any significant morbidity to the patients.
  • Feasibility of arterial spin labeling in evaluating high- and low-flow peripheral vascular malformations: a case series

    Ramachandran, Sanjeev; Delf, Jonathan; Adair, William; Rayt, Harjeet; Bown, Matthew; Kandiyil, Neghal (2021)
    We present a case series highlighting a novel use of arterial spin labeling (ASL), a MRI perfusion technique, to evaluate both high- and low-flow peripheral vascular malformations (PVMs) across a range of anatomical locations. While the role of ASL in assessing intracranial vascular malformations is more established, there is limited evidence for PVMs. Our results provide preliminary evidence for the feasibility of ASL in imaging PVMs and its potential ability to distinguish between high- and low-flow PVMs. In addition, we demonstrate its ability to identify focal high blood flow, which may indicate the nidus in arteriovenous malformations. Together, these findings have important implications for patient management. We also outline the potential benefits and limitations of ASL in the imaging of PVMs, and provide justification for further validation of its diagnostic performance.
  • Accidental neutron exposure in a medical setting: a case study

    Peet, Debbie (2020)
    In May 2016, a new linear accelerator (Linac) was installed at a hospital oncology department. A team of individuals supervised the installation, including a Radiation Oncologist who acted as an independent observer to the installation, calibration, beam data collection and shielding measurements. In order to ensure the shielding was correct, a licensed representative of the Turkish Atomic Energy Authority carried out formal measurements of the gamma and neutron dose rates at a variety of locations in and around the Linac facility. At 18 MV, the maximum neutron dose rate was 172μSv h-1and the maximum gamma dose rate was approximately 2μSv h-1(ambient dose equivalent in both cases), significantly higher than the expected and local background doses. As the neutron dose rates in particular were so high, it was concluded that the shielding was not sufficient, potentially due to an inadequate design. In order to rule out overexposure during the installation, biological dosimetry was carried out for a number of the individuals involved. The estimated doses were closely aligned with the doses measured using commercially available neutron dosemeters and were also within the tolerance dose ranges estimated using Monte Carlo simulations, which also supported the investigation. The results underline the need for careful planning before and after installation of new radiation exposure facilities, especially high MV Linac operation for which photo-neutrons might need to be mitigated. The results clearly indicate the importance of such checks, in addition to demonstrating the relevance of biological dosimetry supported by modelling strategies complex or unclear exposure scenarios.
  • Phosphaturic mesenchymal tumors: radiological aspects and suggested imaging pathway

    Hussein, Mohsin; Rennie, Winston (2021)
    Phosphaturic mesenchymal tumors (PMTs) are rare mesenchymal neoplasms of soft tissue or bone origin that can give rise to a challenge in diagnostic imaging. These tumors are frequently associated with tumor-induced osteomalacia, also called oncogenic osteomalacia, which is a rare paraneoplastic syndrome characterized by ectopic secretion of fibroblast growth factor 23, a hormone that regulates serum phosphate level. PMTs show polymorphic features on both radiological findings and histological examination, causing problems in diagnosis owing to their similarity with other mesenchymal tumors. Thus, this paper aims to describe radiological aspects of PMTs and suggest an imaging pathway for accurate diagnosis throughout the evidence from the literature review.
  • Ultrasound shear wave elastography imaging of common carotid arteries in patients with Spontaneous Coronary Artery Dissection (SCAD)

    Marsh, Anna-Marie; Samani, Nilesh; McCann, Gerry; Adlam, David; Chung, Emma; Ramnarine, Kumar (2022)
    Background: Shear wave elastography (SWE) is emerging as a valuable clinical tool for a variety of conditions. The aim of this pilot study was to assess the potential of SWE imaging of the common carotid arteries (CCA) in patients with spontaneous coronary artery dissection (SCAD), a rare but potentially life-threatening condition, hypothesized to be linked to changes in vessel wall elasticity. Methods: Ultrasound shear wave elastography (SWE) estimates of artery wall elasticity were obtained from the left and right CCAs of 89 confirmed SCAD patients and 38 non-dissection controls. SWE images obtained over multiple cardiac cycles were analysed by a blinded observer to estimate elasticity in the form of a Young's Modulus (YM) value, across regions of interest (ROI) located within the anterior and posterior CCA walls. Results: YM estimates ranged from 17 to 133 kPa in SCAD patients compared to 34 to 87 kPa in non-dissection controls. The mean YM of 55 [standard deviation (SD): 21] kPa in SCAD patients was not significantly different to the mean of 57 [SD: 12] kPa in controls, p = 0.32. The difference between groups was 2 kPa [95% Confidence Interval - 11, 4]. Conclusions: SWE imaging of CCAs in SCAD patients is feasible although the clinical benefit is limited by relatively high variability of YM values which may have contributed to our finding of no significant difference between SCAD patients and non-dissection controls.