Role of probiotics in chronic rhinosinusitis: a systematic review of randomised, controlled trials

OBJECTIVE

This review evaluated the safety profile and efficacy of probiotics in chronic rhinosinusitis and was registered with Prospero (Centre for Reviews and Dissemination number: 42020193529).

METHOD

Literature databases were searched through inception to August 2022. Randomised, controlled trials exploring adjunctive probiotics in adult chronic rhinosinusitis patients were included. From 948 records screened, 4 randomised, controlled trials were included.

RESULTS

Probiotics-associated adverse effects comprised epistaxis and abdominal pain. No reduction in Sino-Nasal Outcome Test values before 4 weeks (p = 0.58) or beyond 8 weeks (p = 0.08) of treatment or reduction of severe symptom frequency (p = 0.75) was observed. Symptom relapse in probiotic-treated patients was significantly lower across all timepoints (p = 0.045). Lower sinusitis relapse risks during treatment (risk ratio = 0.49; p = 0.019) and 8 months post-treatment (risk ratio = 0.56, p = 0.013) were observed. Probiotics demonstrated potential in improving Sino-Nasal Outcome Test symptom subscales, including sleep, psychological and rhinology subscales.

CONCLUSION

The optimal mode of probiotic administration, treatment duration and target patient subgroups requires further study to evaluate the utility of probiotics.

Time for change? Feasibility of introducing micromodules into medical student education: a randomised controlled trial

INTRODUCTION

Didactic lectures have been the foundation of learning for many medical students. However, in recent years, the flipped classroom model has become increasingly popular in medical education. This approach enhances pre-class learning, allowing the limited contact time between clinicians and medical students to be focused on practical issues. This study evaluated the effectiveness and non-inferiority of online micromodule teaching in terms of knowledge transfer concerning specific urology topics.

METHODS

Medical students without prior exposure to the urology subspecialty were enrolled in the study, then randomised to a traditional didactic lecture group or an online micromodule group. Knowledge transfer was assessed by pre-intervention and post-intervention multiple-choice questions and objective structured clinical examinations that involved the acquisition of medical histories from real patients.

RESULTS

In total, 45 medical students were enrolled (22 in the traditional didactic group and 23 in the online micromodule group). In terms of knowledge transfer (assessed by objective structured clinical examinations), the efficacy of online micromodules was comparable to traditional didactic lectures, although the difference was not statistically significant (P=0.823). There were no significant differences in terms of knowledge acquisition, retention, or clinical application between the two groups.

CONCLUSION

In terms of acquiring, retaining, and applying foundational urological knowledge, online micromodules can help medical students to achieve outcomes comparable with the outcomes of didactic lectures. Online micromodules may be a viable alternative to traditional didactic lectures in urology education.

A method for estimating and characterizing explicitly nonlinear dynamic functional network connectivity in resting-state fMRI data

The past 10 years have seen an explosion of approaches that focus on the study of time-resolved change in functional connectivity (FC). FC characterization among networks at a whole-brain level is frequently termed functional network connectivity (FNC). Time-resolved or dynamic functional network connectivity (dFNC) focuses on the estimation of transient, recurring, whole-brain patterns of FNC. While most approaches in this area have attempted to capture dynamic linear correlation, we are particularly interested in whether explicitly nonlinear relationships, above and beyond linear, are present and contain unique information. This study thus proposes an approach to assess explicitly nonlinear dynamic functional network connectivity (EN dFNC) derived from the relationship among independent component analysis time courses. Linear relationships were removed at each time point to evaluate, typically ignored, explicitly nonlinear dFNC using normalized mutual information (NMI). Simulations showed the proposed method estimated explicitly nonlinearity over time, even within relatively short windows of data. We then, applied our approach on 151 schizophrenia patients, and 163 healthy controls fMRI data and found three unique, highly structured, mostly long-range, functional states that also showed significant group differences. In particular, explicitly nonlinear relationships tend to be more widespread than linear ones. Results also highlighted a state with long range connections to the visual domain, which were significantly reduced in schizophrenia. Overall, this work suggests that quantifying EN dFNC may provide a complementary and potentially valuable tool for studying brain function by exposing relevant variation that is typically ignored.

RF12 | PSUN106 Quantifying Liver and Brain Levels of 11β-hydroxysteroid Dehydrogenase Type 1 in Obesity Using Positron Emission Tomography Imaging

Objectives

Cortisol is known to promote adipocyte differentiation and maturation, and prolonged exposure to excess cortisol contributes to the development of obesity and metabolic dysregulation. The intracellular 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme catalyzes the conversion of inactive cortisone to active cortisol. Recently, we demonstrated reduced brain 11β-HSD1 levels in vivo with increasing body mass index (BMI), using positron emission tomography (PET) radioligands [¹¹C]- and [¹⁸F]AS2471907(1). PET imaging can simultaneously quantify uptake in multiple organs (e.g., liver/brain). [¹⁸F]AS2471907 has high uptake and specific binding in the brain and liver(2). Liver and brain 11β-HSD1 measured by PET imaging may help elucidate the roles of cortisol activation in the setting of metabolic dysregulation. Thus, we performed PET imaging studies to examine 11β-HSD1 levels in the liver and brain.

Methods

Nine individuals (5F/4M) with a range of BMIs (22.6-34.4 kg/m²) underwent a 90 min PET/CT acquisition with arterial plasma sampling after injection of [¹⁸F]AS2471907. Regions-of-interest (ROI) for the liver were manually drawn on a summed PET image (60-90 min). Seventeen brain ROIs were selected from the anatomical automatic labeling (AAL) template and applied to the dynamic PET images to generate time-activity-curves (TACs). Brain volume of distribution (VT, mL/cm³), the target tissue to plasma ratio of radioligand at equilibrium, was estimated for each ROI using the multilinear analysis-1 method with plasma input function. Mean whole-brain VT values were calculated by averaging all ROIs. Given the appearance of irreversible kinetics in the liver, Ki (min-1), the rate of irreversible tracer uptake, was calculated using the Patlak method.

Results

Qualitative brain and liver uptake was assessed by examining a summed PET image (SUV 60-90min). The parent fraction in plasma was 88±1% at 90 min, indicating negligible plasma radiolabeled-metabolites contributing the measured signal in the liver. Kinetic modeling estimates demonstrated decreasing whole brain VT with increasing BMI (R²=0.53), similar to our previously published study examining only brain in a larger cohort(1). Patlak methods provided good estimates of Ki. In an opposite manner from the brain, correlations seen in the liver using Ki were positively correlated with BMI (R²=0.57).

Conclusions

These preliminary studies suggest obesity is associated with increased 11β-HSD1 levels in the liver but decreased 11β-HSD1 levels in the brain. Clinically, liver specific 11β-HSD1 inhibitors may prove beneficial in treating metabolic sequalae of obesity such non-alcoholic fatty liver disease (NAFLD) by inhibiting activity of higher 11β-HSD1 levels. Further studies in NAFLD and obesity are necessary to determine appropriate populations that would benefit from 11β-HSD1 inhibitors and longitudinal in vivo PET imaging to help inform development of future therapeutics.

References

[1] Bini, et al, Molecular Imaging and Biology, 2020. [2] Bini, et al, IEEE Trans on Radiation and Plasma Medical Sciences, 2021

Presentation: Saturday, June 11, 2022 1:42 p.m. - 1:47 p.m., Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Radiotherapy Quality Assurance in the PORTEC-3 (TROG 08.04) Trial

AIMS

Quality assurance in radiotherapy (QART) is essential to ensure the scientific integrity of a clinical trial. This paper reports the findings of the retrospective QART assessment for all centres that participated in PORTEC-3; a randomised controlled trial that compared pelvic radiotherapy with concurrent chemoradiotherapy to the pelvis followed by adjuvant chemotherapy. The trial showed an overall survival benefit for the addition of the chemotherapy in the management of women with high-risk endometrial cancer.

MATERIALS AND METHODS

Clinicians were invited to upload a randomly selected case/s treated at each of the participating sites. Panel reviewers analysed the contours to certify that the target volumes and organ at risk structures were contoured according to guidelines. The results were categorised into acceptable, minor variation, major variation or unevaluable. The radiotherapy plans were dosimetrically evaluated using the well-established Trans-Tasman Radiation Oncology Group (TROG) protocol.

RESULTS

Between August 2010 and January 2018, data from 146 patients of 686 consecutively treated patients were retrospectively reviewed. All 16 Australia and New Zealand and 71 of 77 international centres uploaded data for evaluation. In total, 3514 dosimetric and contour variables were reviewed. Of these, 3136 variables were deemed acceptable (89.2%), with 335 minor (9.6%) and 43 major variations (1.2%). Major contour variations included the clinical target volume vaginal vault, clinical target volume parametria and differential planning target volume vault expansion.

CONCLUSION

The results of the QART assessment confirmed high uniformity and low rates of both minor and major deviations in contouring and dosimetry in all sites. This supports the safe introduction of the PORTEC-3 treatment protocol into routine clinical practice.

457 The Effect of Biochemical Adversity of Primary Hyperparathyroidism on Preoperative Imaging (SPECT-CT and US Parathyroids)

Aim

Primary hyperparathyroidism (PHPT) is a common endocrine disorder, with an estimated incidence of 1/500 women and 1/2000 men older than 40 years. Several factors influence the positivity of preoperative scans including serum calcium, PTH and vitamin D levels, and gland size. The aim of our study is to examine the effect of biochemical adversity of primary hyperparathyroidism on preoperative imaging (SPECT-CT and US parathyroids).

Method

Retrospective study of 176 parathyroidectomies (2017-2020) in a tertiary referral centre with biochemistry, SPECT-CT, US parathyroids and histology outcomes being recorded. Failed parathyroidectomies were excluded.

Results

Patients were divided into 4 groups based on the preoperative calcium levels (normocalcemia <2.6, 3.4%; mild 2.60-2.79, 51.1%; moderate 2.80-2.99, 31.2%; severe >3.0 mmol/l, 14.2% of patients). Age (p-0.0297), preoperative vitamin D (p-0.03) and PTH levels (p-0.0001) were different while SPECT-CT positivity (p-0.29) weight of gland (p-0.015) and US positivity (p-0.09) were similar within the subgroups. Looking at the whole group, patients with positive SPECT-CT have a larger weight (p < 0.0001) while preoperative PTH levels was higher for the positive SPECT-CT patients (p-0.0289). No relation was identified between calcium levels and SPECT-CT positivity (p-0.18). No significance between preoperative vitamin D and positivity of US and SPECT-CT within the study group were noted.

Conclusions

Serum PTH levels and weight of the gland are directly correlated with positivity of preoperative imaging. Preoperative calcium and vitamin D levels correlates indirectly with the severity of the disease but did not influence the preoperative imaging positivity.

Perceptions of the use of artificial intelligence in the diagnosis of skin cancer: an outpatient survey

BACKGROUND

Convolutional neural networks (artificial intelligence, AI) are rapidly appearing within the field of dermatology, with diagnostic accuracy matching that of dermatologists. As technologies become available for use by both the health professionals and the general public, their uptake in healthcare will become more acceptable. National Health Service England recognizes the potential of AI for healthcare but emphasizes that patient-centred care should be at the forefront of these technological advancements.

AIM

To obtain opinions of patients on the use of AI in a dermatology setting, when aiding the diagnosis of skin cancers.

METHODS

A cross-sectional 14-point questionnaire was handed out to patients attending dermatology outpatient skin cancer clinics in two UK hospitals, between March and August 2018.

RESULTS

In total, 603 patient questionnaires were completed. Nearly half (47%; n = 282) of respondents were not concerned if AI technology was used by a skin specialist to aid skin cancer diagnosis. However, the majority (81%; n = 491) of respondents, considered it important for a dermatologist to examine and confirm a diagnosis and to be present for discussion of a cancer diagnosis.

CONCLUSION

Although the majority of respondents were not reluctant about the use of AI for skin cancer diagnosis, respondents still considered it important that dermatologists are involved in the diagnosis and/or confirmation of skin cancer. Furthermore, the study results demonstrate that personal interaction with a clinician is important. This is in keeping with proposals that AI be used as an adjunctive technology to increase accuracy of skin cancer diagnoses, but not as a substitute for a dermatologist.

Effect of age on brain metabotropic glutamate receptor subtype 5 measured with [18F]FPEB PET

OBJECTIVE

Metabotropic glutamate receptor subtype 5 (mGluR5) is integral to the brain glutamatergic system and cognitive function. This study investigated whether aging is associated with decreased brain mGluR5 availability.

METHODS

Cognitively normal participants (n = 45), aged 18 to 84 years, underwent [18F]FPEB positron emission tomography scans to quantify brain mGluR5. Distribution volume (VT) was computed using a venous or arterial input function and equilibrium modeling from 90 to 120 min. In the primary analysis, the association between age and VT in the hippocampus and association cortex was evaluated using a linear mixed model. Exploratory analyses assessed the association between age and VT in multiple brain regions. The contribution of gray matter tissue alterations and partial volume effects to associations with age was also examined.

RESULTS

In the primary analysis, older age was associated with lower [18F]FPEB binding to mGluR5 (P = 0.026), whereas this association was not significant after gray matter masking or partial volume correction to account for age-related tissue loss. Post hoc analyses revealed an age-related decline in mGluR5 availability in the hippocampus of 4.5% per decade (P = 0.007) and a non-significant trend in the association cortex (P = 0.085). An exploratory analysis of multiple brain regions revealed broader inverse associations of age with mGluR5 availability, but not after partial volume correction.

CONCLUSION

Reductions in mGluR5 availability with age appear to be largely mediated by tissue loss. Quantification of [18F]FPEB binding to mGluR5 may expand our understanding of age-related molecular changes and the relationship with brain tissue loss.

Prediction models and questionnaires developed to predict vitamin D status in adults: a systematic review

A systematic review of prediction models/questionnaires developed to identify people with deficient/insufficient vitamin D status shows the potential of self-reported information to estimate vitamin D status. The objective is to identify and compare existing screening tools, developed to identify vitamin D deficiency or insufficiency in adults. A systematic search of literature was conducted using MEDLINE, Scopus, Web of Science and CINAHL databases. Risk of bias and applicability concerns were assessed by quality assessment of diagnostic accuracy studies (QUADAS-2). Data were extracted on socio-demographic, anthropometric, risk factors, serum 25 hydroxyvitamin D [25(OH)D] levels, statistical methods and predictive ability. A total of 12 studies were considered for inclusion for this systematic review after screening of 4851 abstracts and 15 full-text articles. Ten of twelve studies developed prediction models and 2 studies developed questionnaires. The majority of studies had low risk of bias and applicability as assessed by QUADAS-2. All studies included only self-reported predictors of vitamin D status in their final models and development of scores. Sunlight exposure and related factors were important significant contributors to the predictive ability of the models and/or questionnaires. Sensitivity and specificity of the prediction models or questionnaires ranged from 55 to 91% and 35 to 84%, respectively. Six out of twelve studies converted final models to scores associated with vitamin D status. There was no evidence that any of these existing tools have been translated into clinical practice. The prediction models or questionnaires identified in this systematic review were moderately sensitive and specific for identifying people with vitamin D deficiency or insufficiency. The substantial contribution of sunlight exposure to the prediction of vitamin D status highlights the importance of including this information when developing vitamin D screening tools.

[11C]Methionine and [11C]PBR28 as PET Imaging Tracers to Differentiate Metastatic Tumor Recurrence or Radiation Necrosis

Purpose:

As stereotactic radiosurgery (SRS) and immunotherapy are increasingly used to treat brain metastases, incidence of radiation necrosis (RN) is consequently rising. Differentiating tumor regrowth (TR) from RN is vital in management but difficult to assess using MRI. We hypothesized that tumor methionine levels would be elevated given increased metabolism and high amino acid uptake, whereas RN would increase inflammation marked by upregulated translocator protein (PBR-TSPO), which can be quantified with specific PET tracers.

Procedures:

We performed a feasibility study to prospectively evaluate [¹¹C]methionine and [¹¹C]PBR28 using PET in 5 patients with 7 previously SRS-treated brain metastases demonstrating regrowth to differentiate TR from RN.

Results:

Sequential imaging with dual tracers was well-tolerated. [¹¹C]methionine was accurate for detecting pathologically confirmed TR in 7/7 lesions, whereas [¹¹C]PBR28 was only accurate in 3/7 lesions. Tumor PBR-TSPO expression was elevated in both melanoma and lung cancer cells, contributing to lack of specificity of [¹¹C]PBR28-PET.

Conclusion:

Sequential use of PET tracers is safe and effective. [¹¹C]Methionine was a reliable TR marker, but [¹¹C]PBR28 was not a reliable marker of RN. Studies are needed to determine the causes of post-radiation inflammation and identify specific markers of RN to improve diagnostic imaging.

AB1126 THE RELIABILITY AND DIAGNOSTIC ACCURACY OF DIGITAL TOMOSYNTHESIS COMPARED WITH CONVENTIONAL RADIOGRAPHY FOR THE INVESTIGATION OF SACROILIITIS

Background:

Conventional radiography remains part of the diagnosis of axial spondyloarthritis and determines qualification for biologic disease modifying anti-rheumatic drugs in many countries. The standard anteroposterior radiograph (XR) incompletely images the complex sacroiliac joint with recognised unacceptably low levels of agreement between readers. Digital tomosynthesis (DTS) uses conventional radiographic projections to create a three-dimensional image and is a potential alternative for the initial radiographic detection and grading of sacroiliitis.

Objectives:

To compare the level of agreement between two radiologists when reporting sacroiliac joint imaging with digital tomosynthesis versus conventional radiography, as well as to compare the diagnostic accuracy of each imaging modality.

Methods:

229 consecutive patients that had radiography and digital tomosynthesis performed at Footscray Hospital, Melbourne, Australia were included. Two blinded radiologists independently re-reported all images according to the modified New York criteria, or listed an alternative diagnosis. An overall assessment of each image as inflammatory sacroiliitis, normal or non-inflammatory disease was also recorded. Demographic and clinical data were extracted from medical records. Agreement between and within readers was evaluated using kappa (κ) statistic. Diagnostic accuracy was calculated by comparing each reader’s overall assessment against 2 reference standard comparators: most recent rheumatologist diagnosis and fulfillment of ASAS criteria at any time point.

Results:

The intra-reader agreement of reader 1 was almost perfect for the left, right and overall sacroiliac joint assessments (κ 0.77 - 0.94), with DTS outperforming XR. Reader 2 agreement was mostly moderate (κ 0.39 - 0.69), with DTS and XR better on the left and right sacroiliac joint respectively, but XR having better overall assessment. The inter-reader agreement of DTS for all patients was moderate and better than XR as shown in the Table. When excluding non-spondyloarthritis patients, inter-reader agreement improved (κ 0.50 to 0.58) but there was no significant difference between DTS and XR. Using reader 1, the sensitivity of DTS (64.8 - 66.7%) was better than XR (54.9 - 60.7%) but low, in keeping with what is known about radiographic sacroiliitis and axial spondyloarthritis. The specificity of XR (78.5 – 80.3%) was better than DTS (72.3 – 73.1%). There were no significant differences when fulfillment of modified New York Criteria was used as a reader’s positive test.

Table.

Inter-rater reliability between the readers

All patients(N=229)*Inflammatory sacroiliitis & normal patients (N=164)**Inflammatory sacroiliitis patients (N=92)**XR Right0.360.520.56DTS Right0.390.500.51XR Left0.340.550.56DTS Left0.420.550.58XR Overall0.40DTS Overall0.45

*Non-weighted kappa statistic

**Weighted kappa statistic

Conclusion:

DTS demonstrated moderate reliability for assessment of sacroiliitis, marginally better than conventional radiography. Overall levels of agreement for both imaging modalities were however lower than radiography in previous studies, with several possible contributing factors. A prospective study in a selected spondyloarthritis cohort may better determine any benefit of DTS.

References:

[1]Christiansen AA, Hendricks O, Kuettel D, Horslev-Petersen K, Jurik AG, Nielsen S, et al. Limited Reliability of Radiographic Assessment of Sacroiliac Joints in Patients with Suspected Early Spondyloarthritis. The Journal of rheumatology. 2017;44(1):70-7.

[2]van Tubergen A, Heuft-Dorenbosch L, Schulpen G, Landewe R, Wijers R, van der Heijde D, et al. Radiographic assessment of sacroiliitis by radiologists and rheumatologists: does training improve quality? Annals of the rheumatic diseases. 2003;62(6):519-25.

Disclosure of Interests:

None declared

PET imaging of mGluR5 in Alzheimer's disease

BACKGROUND

Metabotropic glutamate subtype 5 receptors (mGluR5) modulate synaptic transmission and may constitute an important therapeutic target in Alzheimer's disease (AD) by mediating the synaptotoxic action of amyloid-β oligomers. We utilized the positron emission tomography (PET) radioligand [18F]FPEB to investigate mGluR5 binding in early AD.

METHODS

Sixteen individuals with amnestic mild cognitive impairment (MCI) due to AD or mild AD dementia who were positive for brain amyloid were compared to 15 cognitively normal (CN) participants who were negative for brain amyloid. Diagnostic groups were well balanced for age, sex, and education. Dynamic PET scans were acquired for 60 min, starting at 60 min after the initial administration of up to 185 MBq of [18F]FPEB using a bolus-plus-constant-infusion method (Kbol = 190 min). Equilibrium modeling with a cerebellum reference region was used to estimate [18F]FPEB binding (BPND) to mGluR5. Analyses were performed with and without corrections for gray matter atrophy and partial volume effects.

RESULTS

Linear mixed model analysis demonstrated a significant effect of group (p = 0.011) and the group × region interaction (p = 0.0049) on BPND. Post hoc comparisons revealed a significant reduction (43%) in mGluR5 binding in the hippocampus of AD (BPND = 0.76 ± 0.41) compared to CN (BPND = 1.34 ± 0.58, p = 0.003, unpaired t test) participants, and a nonsignificant trend for a reduction in a composite association cortical region in AD (BPND = 1.57 ± 0.25) compared to CN (BPND = 1.86 ± 0.63, p = 0.093) participants. Exploratory analyses suggested additional mGluR5 reductions in the entorhinal cortex and parahippocampal gyrus in the AD group. In the overall sample, hippocampal mGluR5 binding was associated with episodic memory scores and global function.

CONCLUSIONS

[18F]FPEB-PET revealed reductions in hippocampal mGluR5 binding in early AD. Quantification of mGluR5 binding in AD may expand our understanding of AD pathogenesis and accelerate the development of novel biomarkers and treatments.

PET Imaging of Pancreatic Dopamine D2 and D3 Receptor Density with 11C-(+)-PHNO in Type 1 Diabetes

Type 1 diabetes mellitus (T1DM) has traditionally been characterized by a complete destruction of β-cell mass (BCM); however, there is growing evidence of possible residual BCM present in T1DM. Given the absence of in vivo tools to measure BCM, routine clinical measures of β-cell function (e.g., C-peptide release) may not reflect BCM. We previously demonstrated the potential utility of PET imaging with the dopamine D₂ and D₃ receptor agonist 3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4]oxazin-9-ol (¹¹C-(+)-PHNO) to differentiate between healthy control (HC) and T1DM individuals. Methods: Sixteen individuals participated (10 men, 6 women; 9 HCs, 7 T1DMs). The average duration of diabetes was 18 ± 6 y (range, 14-30 y). Individuals underwent PET/CT scanning with a 120-min dynamic PET scan centered on the pancreas. One- and 2-tissue-compartment models were used to estimate pancreas and spleen distribution volume. Reference region approaches (spleen as reference) were also investigated. Quantitative PET measures were correlated with clinical outcome measures. Immunohistochemistry was performed to examine colocalization of dopamine receptors with endocrine hormones in HC and T1DM pancreatic tissue. Results: C-peptide release was not detectable in any T1DM individuals, whereas proinsulin was detectable in 3 of 5 T1DM individuals. Pancreas SUV ratio minus 1 (SUVR-1) (20-30 min; spleen as reference region) demonstrated a statistically significant reduction (-36.2%) in radioligand binding (HCs, 5.6; T1DMs, 3.6; P = 0.03). Age at diagnosis correlated significantly with pancreas SUVR-1 (20-30 min) (R ² = 0.67, P = 0.025). Duration of diabetes did not significantly correlate with pancreas SUVR-1 (20-30 min) (R ² = 0.36, P = 0.16). Mean acute C-peptide response to arginine at maximal glycemic potentiation did not significantly correlate with SUVR-1 (20-30 min) (R ² = 0.57, P = 0.05), nor did mean baseline proinsulin (R ² = 0.45, P = 0.10). Immunohistochemistry demonstrated colocalization of dopamine D₃ receptor and dopamine D₂ receptor in HCs. No colocalization of the dopamine D₃ receptor or dopamine D₂ receptor was seen with somatostatin, glucagon, or polypeptide Y. In a separate T1DM individual, no immunostaining was seen with dopamine D₃ receptor, dopamine D₂ receptor, or insulin antibodies, suggesting that loss of endocrine dopamine D₃ receptor and dopamine D₂ receptor expression accompanies loss of β-cell functional insulin secretory capacity. Conclusion: Thirty-minute scan durations and SUVR-1 provide quantitative outcome measures for ¹¹C-(+)-PHNO, a dopamine D₃ receptor-preferring agonist PET radioligand, to differentiate BCM in T1DM and HCs.

Outcomes of transperineal and transrectal ultrasound-guided prostate biopsy

OBJECTIVE

To compare the clinical outcomes and pathological findings of transperineal ultrasound-guided prostate biopsy (TPUSPB) and transrectal ultrasound-guided prostate biopsy (TRUSPB) in a secondary referral hospital.

METHODS

This was a retrospective study of 100 TPUSPBs and 100 TRUSPBs performed in our centre. Pre-biopsy patient parameters (eg, patient age, clinical staging, serum prostate-specific antigen [PSA] level, prostate size, and PSA density), as well as pathological results and 30-day complication and readmission rates, were retrieved from the patients' medical records and compared between the two groups.

RESULTS

One hundred TPUSPBs performed from January 2018 to May 2018 and 100 TRUSPBs performed from January 2016 to April 2016 were included for analysis. Mean age did not significantly differ between the groups. The TPUSPB group had a higher mean PSA level, smaller prostate size, and higher PSA density, compared with the TRUSPB group. The overall prostate cancer detection rate was similar between the TPUSPB and TRUSPB groups (35% vs 25%, P=0.123). There were no significant differences between the groups in prostate cancer detection rates after stratification according to PSA density and clinical staging. With respect to complications, no patients developed fever in the TPUSPB group, while 4% of patients in the TRUSPB group had fever and required at least 1-week admission for intravenous antibiotic administration.

CONCLUSION

For prostate biopsy, TPUSPB is safer, with no infection complications, and has similar prostate cancer detection rate compared with TRUSPB.

Spontaneous spinal epidural haematomas in children

PURPOSE

To understand the typical presentation, risk factors, location and size, treatment, neurological recovery and survival of spontaneous spinal epidural haematomas (SSEH) in children.

METHODS

A systematic review of the English literature from 1 January 1960 to 1 March 2018 was performed on children aged 18 years and younger. Individual patient data were extracted and collated. Outcome measures were mode of presentation, risk factors, initial neurological findings, initial presumed diagnosis, diagnostic investigations, site and size of the SSEH, treatment, neurological recovery and survival.

RESULTS

Thirty-one publications and 36 patients were reviewed. All age groups were affected. 83% of patients did not have a known risk factor. Back pain was reported in 61% and neurological dysfunction in 97% of patients, although not all articles defined these parameters. Initially 28% of patients were suspected of having an alternative diagnosis. All patients had an MRI and/or CT scan confirming the diagnosis. The cervical-thoracic region was most commonly affected, and the average haematoma size extended across 6.3 vertebral levels. Surgical decompression was performed in 72% of patients. Neurological function improved in 83% of patients. Two patients died as a consequence of their SSEH.

CONCLUSIONS

SSEHs affect all paediatric age groups and typically present with neurological dysfunction and/or back pain. The initial diagnosis is incorrect in up to 28% of cases, but cross-sectional spinal imaging is diagnostic. Most SSEHs are located in the cervico-thoracic region and affect multiple spinal levels. The treatment depends on whether the patient has a bleeding disorder and their neurological status. These slides can be retrieved under Electronic Supplementary Material.

Evaluation of Pancreatic VMAT2 Binding with Active and Inactive Enantiomers of [18F]FP-DTBZ in Healthy Subjects and Patients with Type 1 Diabetes

PURPOSE

Previous studies demonstrated the utility of [¹⁸F]fluoropropyl-(+)-dihydrotetrabenazine ([¹⁸F]FP-(+)-DTBZ) as a positron emission tomography (PET) radiotracer for the vesicular monoamine transporter type 2 (VMAT2) to quantify beta cell mass in healthy control (HC) and type 1 diabetes mellitus (T1DM) groups. Quantification of specific binding requires measurement of non-displaceable uptake. Our goal was to identify a reference tissue (renal cortex or spleen) to quantify pancreatic non-specific binding of [¹⁸F]FP-(+)-DTBZ with the inactive enantiomer, [¹⁸F]FP-(-)-DTBZ. This was the first human study of [¹⁸F]FP-(-)-DTBZ.

PROCEDURES

Six HCs and four T1DM patients were scanned on separate days after injection of [¹⁸F]FP-(+)-DTBZ or [¹⁸F]FP-(-)-DTBZ. Distribution volumes (V_T) and standardized uptake values (SUVs) were compared between groups. Three methods for calculation of non-displaceable uptake (V_ND) or reference SUV were applied: (1) use of [¹⁸F]FP-(+)-DTBZ reference V_T as V_ND, assuming V_ND is uniform across organs; (2) use of [¹⁸F]FP-(-)-DTBZ pancreatic V_T as V_ND, assuming that V_ND is uniform between enantiomers in the pancreas; and (3) use of a scaled [¹⁸F]FP-(+)-DTBZ reference V_T as V_ND, assuming that a ratio of non-displaceable uptake between organs is uniform between enantiomers. Group differences in V_T (or SUV), binding potential (BP_ND), or SUV ratio (SUVR) were estimated using these three methods.

RESULTS

[¹⁸F]FP-(-)-DTBZ V_T values were different among organs, and V_T(+) and V_T(-) were also different in the renal cortex and spleen. Method 3 with the spleen to estimate V_ND (or reference SUV) gave the highest non-displaceable uptake and the largest HC vs. T1DM group differences. Significant group differences were also observed in V_T (or SUV) with method 1 using spleen. SUV was affected by differences in the input function between groups and between enantiomers.

CONCLUSIONS

Non-displaceable uptake was different among organs and between enantiomers. Use of scaled spleen V_T values for V_ND is a suitable method for quantification of VMAT2 in the pancreas.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Factors associated with the orthopaedic surgeon's decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1905 patients

OBJECTIVE

To determine factors associated with orthopaedic surgeons' decision to recommend total joint replacement (TJR) in people with knee and hip osteoarthritis (OA).

DESIGN

Cross-sectional study in eleven countries. For consecutive outpatients with definite hip or knee OA consulting an orthopaedic surgeon, the surgeon's indication of TJR was collected, as well as patients' characteristics including comorbidities and social situation, OA symptom duration, pain, stiffness and function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), joint-specific quality of life, Osteoarthritis Research Society International (OARSI) joint space narrowing (JSN) radiographic grade (0-4), and surgeons' characteristics. Univariable and multivariable logistic regressions were performed to identify factors associated with the indication of TJR, adjusted by country.

RESULTS

In total, 1905 patients were included: mean age was 66.5 (standard deviation [SD], 10.8) years, 1082 (58.0%) were women, mean OA symptom duration was 5.0 (SD 7.0) years. TJR was recommended in 561/1127 (49.8%) knee OA and 542/778 (69.7%) hip OA patients. In multivariable analysis on 516 patients with complete data, the variables associated with TJR indication were radiographic grade (Odds Ratio, OR for one grade increase, for knee and hip OA, respectively: 2.90, 95% confidence interval [1.69-4.97] and 3.30 [2.17-5.03]) and WOMAC total score (OR for 10 points increase: 1.65 [1.32-2.06] and 1.38 [1.15-1.66], respectively). After excluding radiographic grade from the analyses, on 1265 patients, greater WOMAC total score was the main predictor for knee and hip OA; older age was also significant for knee OA.

CONCLUSION

Radiographic severity and patient-reported pain and function play a major role in surgeons' recommendation for TJR.

Evaluation of PET Brain Radioligands for Imaging Pancreatic β-Cell Mass: Potential Utility of 11C-(+)-PHNO

Type 1 diabetes mellitus (T1DM) is characterized by a loss of β-cells in the islets of Langerhans of the pancreas and subsequent deficient insulin secretion in response to hyperglycemia. Development of an in vivo test to measure β-cell mass (BCM) would greatly enhance the ability to track diabetes therapies. β-cells and neurologic tissues have common cellular receptors and transporters, therefore, we screened brain radioligands for their ability to identify β-cells. Methods: We examined a β-cell gene atlas for endocrine pancreas receptor targets and cross-referenced these targets with brain radioligands that were available at our institution. Twelve healthy control subjects and 2 T1DM subjects underwent dynamic PET/CT scans with 6 tracers. Results: The D₂/D₃ receptor agonist radioligand ¹¹C-(+)-4-propyl-9-hydroxynaphthoxazine (PHNO) was the only radioligand to demonstrate sustained uptake in the pancreas with high contrast versus abdominal organs such as the kidneys, liver, and spleen, based on the first 30 min of data. Mean SUV from 20 to 30 min demonstrated high uptake of ¹¹C-(+)-PHNO in healthy controls (SUV, 13.8) with a 71% reduction in a T1DM subject with undetectable levels of C-peptide (SUV, 4.0) and a 20% reduction in a T1DM subject with fasting C-peptide level of 0.38 ng/mL (SUV, 11.0). SUV in abdominal organs outside the pancreas did not show measurable differences between the control and T1DM subjects, suggesting that the changes in SUV of ¹¹C-(+)-PHNO may be specific to changes in the pancreas between healthy controls and T1DM subjects. When D₃ and D₂ antagonists were used in nonhuman primates, specific pancreatic binding (SUVR-1) of ¹¹C-PHNO was reduced by 57% and 38%, respectively. Conclusion:¹¹C-(+)-PHNO is a potential marker of BCM, with 2:1 binding of D₃ receptors over D₂ receptors. Further in vitro and in vivo studies to establish D₂/D₃ receptor specificity to β-cells is warranted to characterize ¹¹C-(+)-PHNO as a candidate for clinical measurement of BCM in healthy control and diabetic subjects.

Evaluation of (-)-[18 F]Flubatine-specific binding: Implications for reference region approaches

We aimed to characterize changes in binding of (-)-[¹⁸ F]Flubatine to α₄ β₂ *-nicotinic acetylcholine receptors (α₄ β₂ *-nAChRs) during a tobacco cigarette smoking challenge. Displacement of (-)-[¹⁸ F]Flubatine throughout the brain was quantified as change in (-)-[¹⁸ F]Flubatine distribution volume (V_T ), with particular emphasis on regions with low V_T . Three tobacco smokers were imaged with positron emission tomography (PET) during a 210 min bolus-plus-constant infusion of (-)-[¹⁸ F]Flubatine. A tobacco cigarette was smoked in the PET scanner ∼125 min after the start of (-)-[¹⁸ F]Flubatine injection. Equilibrium analysis was used to estimate V_T at baseline (90-120 min) and after cigarette challenge (180-210 min), at the time of greatest receptor occupancy by nicotine. Smoking reduced V_T by 21 ± 9% (average ±SD) in corpus callosum, 17 ± 9% in frontal cortex, 36 ± 11% in cerebellum, and 22 ± 10% in putamen. The finding of displaceable (-)-[¹⁸ F]Flubatine binding throughout the brain is an important consideration for reference region-based quantification approaches with this tracer. We observed displacement of (-)-[¹⁸ F]Flubatine binding to α₄ β₂ *-nicotinic acetylcholine receptors in corpus callosum by a tobacco cigarette challenge. We conclude that reference region approaches utilizing corpus callosum should first perform careful characterization of displaceable (-)-[¹⁸ F]Flubatine binding and nondisplaceable kinetics in this putative reference region.