Application of 7T MRS to High-Grade Gliomas

MRS, including single-voxel spectroscopy and MR spectroscopic imaging, captures metabolites in high-grade gliomas. Emerging evidence indicates that 7T MRS may be more sensitive to aberrant metabolic activity than lower-field strength MRS. However, the literature on the use of 7T MRS to visualize high-grade gliomas has not been summarized. We aimed to identify metabolic information provided by 7T MRS, optimal spectroscopic sequences, and areas for improvement in and new applications for 7T MRS. Literature was found on PubMed using "high-grade glioma," "malignant glioma," "glioblastoma," "anaplastic astrocytoma," "7T," "MR spectroscopy," and "MR spectroscopic imaging." 7T MRS offers higher SNR, modestly improved spatial resolution, and better resolution of overlapping resonances. 7T MRS also yields reduced Cramér-Rao lower bound values. These features help to quantify D-2-hydroxyglutarate in isocitrate dehydrogenase 1 and 2 gliomas and to isolate variable glutamate, increased glutamine, and increased glycine with higher sensitivity and specificity. 7T MRS may better characterize tumor infiltration and treatment effect in high-grade gliomas, though further study is necessary. 7T MRS will benefit from increased sample size; reductions in field inhomogeneity, specific absorption rate, and acquisition time; and advanced editing techniques. These findings suggest that 7T MRS may advance understanding of high-grade glioma metabolism, with reduced Cramér-Rao lower bound values and better measurement of smaller metabolite signals. Nevertheless, 7T is not widely used clinically, and technical improvements are necessary. 7T MRS isolates metabolites that may be valuable therapeutic targets in high-grade gliomas, potentially resulting in wider ranging neuro-oncologic applications.

Comparison of switching to 6-week dosing of natalizumab versus continuing with 4-week dosing in patients with relapsing-remitting multiple sclerosis (NOVA): a randomised, controlled, open-label, phase 3b trial

BACKGROUND

Treatment with natalizumab once every 4 weeks is approved for patients with relapsing-remitting multiple sclerosis, but is associated with a risk of progressive multifocal leukoencephalopathy. Switching to extended-interval dosing is associated with lower progressive multifocal leukoencephalopathy risk, but the efficacy of this approach is unclear. We aimed to assess the safety and efficacy of natalizumab once every 6 weeks compared with once every 4 weeks in patients with relapsing-remitting multiple sclerosis.

METHODS

We did a randomised, controlled, open-label, phase 3b trial (NOVA) at 89 multiple sclerosis centres across 11 countries in the Americas, Europe, and Western Pacific. Included participants were aged 18-60 years with relapsing-remitting multiple sclerosis and had been treated with intravenous natalizumab 300 mg once every 4 weeks with no relapses for at least 12 months before randomisation, with no missed doses in the previous 3 months. Participants were randomly assigned (1:1), using a randomisation sequence generated by the study funder and contract personnel with interactive response technology, to switch to natalizumab once every 6 weeks or continue with once every 4 weeks. The centralised MRI reader, independent neurology evaluation committee, site examining neurologists, site backup examining neurologists, and site examining technicians were masked to study group assignments. The primary endpoint was the number of new or newly enlarging T2 hyperintense lesions at week 72, assessed in all participants who received at least one dose of assigned treatment and had at least one postbaseline MRI, relapse, or neurological examination or efficacy assessment. Missing primary endpoint data were handled under prespecified primary and secondary estimands: the primary estimand included all data, regardless of whether participants remained on the assigned treatment; the secondary estimand classed all data obtained after treatment discontinuation or study withdrawal as missing. Safety was assessed in all participants who received at least one dose of study treatment. Study enrolment is closed and an open-label extension study is ongoing. This study is registered with EudraCT, 2018-002145-11, and ClinicalTrials.gov, NCT03689972.

FINDINGS

Between Dec 26, 2018, and Aug 30, 2019, 605 patients were assessed for eligibility and 499 were enrolled and assigned to receive natalizumab once every 6 weeks (n=251) or once every 4 weeks (n=248). After prespecified adjustments for missing data, mean numbers of new or newly enlarging T2 hyperintense lesions at week 72 were 0·20 (95% CI 0·07-0·63) in the once every 6 weeks group and 0·05 (0·01-0·22) in the once every 4 weeks group (mean lesion ratio 4·24 [95% CI 0·86-20·85]; p=0·076) under the primary estimand, and 0·31 (95% CI 0·12-0·82) and 0·06 (0·01-0·31; mean lesion ratio 4·93 [95% CI 1·05-23·20]; p=0·044) under the secondary estimand. Two participants in the once every 6 weeks group with extreme new or newly enlarging T2 hyperintense lesion numbers (≥25) contributed most of the excess lesions. Adverse events occurred in 194 (78%) of 250 participants in the once every 6 weeks group and 190 (77%) of 247 in the once every 4 weeks group, and serious adverse events occurred in 17 (7%) and 17 (7%), respectively. No deaths were reported. There was one case of asymptomatic progressive multifocal leukoencephalopathy (without clinical signs) in the once every 6 weeks group, and no cases in the once every 4 weeks group; 6 months after diagnosis, the participant was without increased disability and remained classified as asymptomatic.

INTERPRETATION

We found a numerical difference in the mean number of new or newly enlarging T2 hyperintense lesions at week 72 between the once every 6 weeks and once every 4 weeks groups, which reached significance under the secondary estimand, but interpretation of statistical differences (or absence thereof) is limited because disease activity in the once every 4 weeks group was lower than expected. The safety profiles of natalizumab once every 6 weeks and once every 4 weeks were similar. Although this trial was not powered to assess differences in risk of progressive multifocal leukoencephalopathy, the occurrence of the (asymptomatic) case underscores the importance of monitoring and risk factor consideration in all patients receiving natalizumab.

FUNDING

Biogen.

Cutting Edge: Effect of Disease-Modifying Therapies on SARS-CoV-2 Vaccine-Induced Immune Responses in Multiple Sclerosis Patients

Multiple sclerosis (MS) is a demyelinating inflammatory disease of the CNS treated by diverse disease-modifying therapies that suppress the immune system. Severe acute respiratory syndrome coronavirus 2 mRNA vaccines have been very effective in immunocompetent individuals, but whether MS patients treated with modifying therapies are afforded the same protection is not known. This study determined that dimethyl fumarate caused a momentary reduction in anti-Spike (S)-specific Abs and CD8 T cell response. MS patients treated with B cell-depleting (anti-CD20) or sphingosine 1-phosphate receptor agonist (fingolimod) therapies lack significant S-specific Ab response. Whereas S-specific CD4 and CD8 T cell responses were largely compromised by fingolimod treatment, T cell responses were robustly generated in anti-CD20-treated MS patients, but with a reduced proportion of CD4⁺CXCR5⁺ circulating follicular Th cells. These data provide novel information regarding vaccine immune response in patients with autoimmunity useful to help improve vaccine effectiveness in these populations.

Radium-223 in the Treatment of Metastatic Castrate-Resistant Prostate Cancer

Background Radium 223 (Ra-223) has been successfully utilised for the treatment of men with metastatic castrate resistant prostate cancer (mCRPC). To date, no real world outcomes from its use in the Irish population have been described. Methods All men referred to our institution for Ra-223 from September 2016 to March 2019 were included. Patient demographics, treatments received, toxicities and outcomes were recorded. Overall survival (OS) and progression free survival (PFS) were analysed using the Kaplan-Meier method. Results Complete data was available for 54 men. Median age was 75 years (range 61-86 years). The median number of prior systemic treatments for mCRPC was 2 (range 0-4). Median ECOG performance status was 1 at the start of treatment and 2 at completion. The median number of Ra-223 cycles received was 4 with 37%(n=20) completing all 6 planned cycles. The most common treatment-related toxicity was fatigue seen in 52% of patients ( n=28). Improved pain scores were documented in 76% of men requiring opioid analgesia at the start of treatment. The median OS was 7 months. A good ECOG performance status, fewer than 6 bone metastases, normal alkaline phosphatase level at start of treatment and chemotherapy naivety were associated with improved OS. Conclusions Ra-223 is a moderately well tolerated palliative treatment amongst Irish men with mCRPC.

In ASCVD, 81 mg and 325 mg of aspirin did not differ for CV or bleeding events

Jones WS, Mulder H, Wruck LM, et al. Comparative effectiveness of aspirin dosing in cardiovascular disease. N Engl J Med. 2021;384:1981-90. 33999548.

Quality of Neurologic Care in the United States: Initial Report From the Axon Registry

OBJECTIVE

To provide the initial description of the quality of outpatient US neurologic care as collected and reported in the Axon Registry.

METHODS

We describe characteristics of registry participants and the performance of neurology providers on 20 of the 2019 Axon Registry quality measures. From the distribution of providers' scores on a quality measure, we calculate the median performance for each quality measure. We test for associations between quality measure performance, provider characteristics, and intrinsic measure parameters.

RESULTS

There were 948 neurology providers who contributed a total of 6,480 provider-metric observations. Overall, the average quality measure performance score at the provider level was 66 (median 77). At the measure level (n = 20), the average quality measure performance score was 53 (median 55) with a range of 2 to 100 (interquartile range 20-91). Measures with a lower-complexity category (e.g., discrete orders, singular concepts) or developed through the specialty's qualified clinical data registry pathway had higher performance distributions. There was no difference in performance between Merit-Based Incentive Payment System (MIPS) and non-MIPS providers. There was no association between quality measure performance and practice size, measure clinical topic/neurologic condition, or measure year of entry.

CONCLUSIONS

This cross-sectional assessment of quality measure performance in 2019 Axon Registry data demonstrates modest performance scores and considerable variability across measures and providers. More complex measures were associated with lower performance. These findings serve as a baseline assessment of quality of ambulatory neurologic care in the United States and provide insights into future measure design.

Denosumab utilization among older adults in Ontario: patient characteristics, persistence with therapy, and return to therapy after an extended gap

We studied 46,797 older adults who initiated denosumab in Ontario, Canada. Patient characteristics remained relatively stable over time and aligned with public reimbursement restrictions. Almost half of patients persisted with therapy for at least 3 years. Fifty-nine percent of patients who discontinued denosumab returned to treatment within 3.6 years.

INTRODUCTION

The purpose of this study was to describe the characteristics of patients who initiated denosumab and estimate persistence with therapy.

METHODS

We identified older adults (aged ≥ 66 years) in Ontario who initiated denosumab between 2012/02 and 2015/03 and followed them to 2016/03. Patient characteristics were summarized using medical and pharmacy claims in the year before starting denosumab and osteoporosis drug use considered since 1996/10. Persistence with denosumab and return after discontinuation (> 90-day gap) were estimated using Kaplan-Meier curves. Analyses were stratified by community and long-term care (LTC) residence.

RESULTS

We identified 46,797 patients (monthly mean = 1263, SD = 187); 97% female, 13% LTC. Community-dwelling patients had a higher prevalence of bone mineral density testing (62% vs. 5%), yet were younger (mean age 78.5 vs. 86.6 years) and had lower prevalence of hip fractures (3% vs. 10%) compared to LTC patients. Eighty-two percent of patients had used osteoporosis medications in the past; 99% of whom took an oral bisphosphonate. Persistence was similar between community-dwelling and LTC patients: 59% persisted ≥ 2 years, 48% ≥ 3 years, and 38% ≥ 4 years, yet a larger proportion of LTC patients returned to denosumab after discontinuation (76% vs. 57%).

CONCLUSIONS

Denosumab utilization is increasing at a steady rate in Ontario. However, persistence remains a concern given the highly reversible pharmacokinetic profile of denosumab that results in a rapid increased fracture risk following discontinuation. Over 80% of patients had a history of oral bisphosphonate therapy, which may persist in bone despite discontinuing denosumab. Consequently, better understanding of denosumab safety and effectiveness among real-world users is important.

Next generation sequencing (NGS) to improve the diagnosis and management of patients with disorders of sex development (DSD)

Disorders of sex development (DSDs) are a diverse group of conditions where the chromosomal, gonadal or anatomical sex can be atypical. The highly heterogeneous nature of this group of conditions often makes determining a genetic diagnosis challenging. Prior to next generation sequencing (NGS) technologies, genetic diagnostic tests were only available for a few of the many DSD-associated genes, which consequently had to be tested sequentially. Genetic testing is key in establishing the diagnosis, allowing for personalised management of these patients. Pinpointing the molecular cause of a patient's DSD can significantly impact patient management by informing future development needs, altering management strategies and identifying correct inheritance pattern when counselling family members. We have developed a 30-gene NGS panel, designed to be used as a frontline test for all suspected cases of DSD (both 46,XX and 46,XY cases). We have confirmed a diagnosis in 25 of the 80 patients tested to date. Confirmed diagnoses were linked to mutations in AMH, AMHR2, AR, HSD17B3, HSD3B2, MAMLD1, NR5A1, SRD5A2 and WT1 which have resulted in changes to patient management. The minimum diagnostic yield for patients with 46,XY DSD is 25/73. In 34/80 patients, only benign or likely benign variants were identified, and in 21/80 patients only variants of uncertain significance (VOUS) were identified, resulting in a diagnosis not being confirmed in these individuals. Our data support previous studies that an NGS panel approach is a clinically useful and cost-effective frontline test for patients with DSDs.

Cystometrogram appearance in PUV is reliably quantified by the shape,wall, reflux and diverticuli (SWRD) score, and presages the need for intervention

OBJECTIVE

Radiological bladder abnormalities in boys with posterior urethral valves (PUV) are well recognised; however, the assessment is subjective. The shape, wall, reflux and diverticuli (SWRD) score objectively assesses shape, wall, reflux and diverticuli in a simple way. This study was undertaken to demonstrate that the SWRD score is reliable, reproducible and correlates with bladder outcome and videourodynamic (VUD) assessment in boys with PUV.

MATERIALS AND METHODS

Three blinded assessors determined the SWRD scores of PUV bladders from cystometrograms taken during VUD from September 2012 to October 2013. The scores were correlated with clinical outcome and VUD pressure measurements. Data were given as median (interquartile range), non-parametric tests used as appropriate (Mann-Whitney U test, or Kruskall-Wallis) and P < 0.05 was taken as significant.

RESULTS

A total of 55 boys with PUV underwent VUD assessment, for which 52 cystometrograms were available. The SWRD score for non-operative management was 1.0 (0.1-1.9) vs 2.0 (1.0-3.3) for operative intervention, P = 0.018 (Summary Figure). The SWRD score for compliant bladders was 1.1 (0.6-2.0) vs hypercompliant 1.7 (0.5-2.8) vs non-compliant 3.3 (2.8-5.0), Kruskall-Wallis P = 0.011. The hostile detrusor overactivity (DO) bladders (Pdet >40 cmH₂O) had a SWRD score of 2.0 (1.3-3.7) vs 1.0 (0.5-2.5) for low-pressure DO bladders, P < 0.05.

DISCUSSION

In this series of patients, increasingly distorted bladder shape was seen to be associated with poor bladder dynamics on VUD. Patients with poorly compliant bladders had a significantly higher SWRD score than normal or megacystis patients. Severe DO was also significantly associated with a high SWRD score. Therefore, the radiological appearance of a hostile bladder represented a marker for high intravesical pressure. VUR and bladder diverticuli may lead to spurious pressure measurements during VUD; however, the SWRD score provided an independent mechanism with which to objectively assess these patients, even in the presence of gross VUR.

CONCLUSIONS

The SWRD score is a simple and objective scoring system for the radiological abnormalities of PUV bladders. It correlates with clinical outcome and VUD assessment of compliance and DO, but is independent of pressure measurements and so not confounded by VUR acting as a 'pop-off' mechanism.

British Association of Paediatric Urologists consensus statement on the management of the neuropathic bladder

INTRODUCTION

A large number of children with spina bifida develop a neuropathic bladder and this group of patients still forms the largest group of children who require urological management. Although there are published guidelines on the management of the neuropathic bladder, they are not specific to children. It is unsurprising, therefore, that the initial investigation, assessment and management of children with spina bifida vary considerably. The 2014 British Association of Paediatric Urologists (BAPU) meeting was devoted to the management of the neuropathic bladder. The aim was to produce a consensus on the appropriate investigation and management of a child with a neuropathic bladder.

METHODS AND MATERIALS

A questionnaire was devised and the members were polled on their current practice. Six paediatric urology fellows presented an evidence-based literature review on different aspects of the neuropathic bladder. At the end of the session, the members of the organisation present were polled again using the same questions.

RESULTS

The BAPU felt that the use of urodynamics in the neuropathic bladder should be selectively determined by clinical parameters. Regarding CIC, the group was evenly split between universal use or only when poor emptying was established. Oxybutinin was the first-line anticholinergic of choice. Most paediatric urologists routinely used Botox and were happy to use it repeatedly. The surgical intervention most frequently employed was determined to be an ileocystoplasty, with most surgeons deferring the need for surveillance cystoscopy until at least 10 years after surgery.

CONCLUSION

It was felt that a consensus statement is not a guideline or a way to establish best practice; however, it serves as a way of surveying current practice and providing a benchmark for clinicians involved in the management of these patients.

Nadir creatinine in posterior urethral valves: How high is low enough?

INTRODUCTION

Large retrospective studies of people with posterior urethral valves (PUV) have reported chronic renal insufficiency (CRI) in up to one third of the participants and end-stage renal failure in up to one quarter of them. Nadir creatinine (lowest creatinine during the first year following diagnosis) is the recognised prognostic indicator for renal outcome in PUV, the most commonly used cut-off being 1 mg/dl (88.4 umol/l).

OBJECTIVE

To conduct a statistical analysis of nadir creatinine in PUV patients in order to identify the optimal cut-off level as a prognostic indicator for CRI.

STUDY DESIGN

Patients treated by endoscopic valve ablation at the present institution between 1993 and 2004 were reviewed. Chronic renal insufficiency was defined as CKD2 or higher. Statistical methods included receiver operating characteristic (ROC) curve analysis, Fisher exact test and diagnostic utility tests. Statistical significance was defined as P < 0.05.

RESULTS AND DISCUSSION

Nadir creatinine was identified in 96 patients. The median follow-up was 9.4 (IQR 7.0, 13.4) years. A total of 29 (30.2%) patients developed CRI, with nine (9.4%) reaching end-stage renal failure. On ROC analysis, Nadir creatinine was highly prognostic for future CRI, with an Area Under the Curve of 0.887 (P < 0.001). Renal insufficiency occurred in all 10 (100%) patients with nadir creatinine >88.4 umol/l compared with 19 of 86 (22.2%) patients with lower nadir creatinine (P < 0.001). As a test for future CRI, a nadir creatinine cut-off of 88.4 umol/l gave a specificity of 100%, but poor sensitivity of 34.5%. Lowering the cut-off to 75 umol/l resulted in improvement in all diagnostic utility tests (Table). All 14 (100%) patients with nadir creatinine >75 umol/l developed CRI, compared with 15 of 82 (18.3%) patients with lower nadir creatinine (P < 0.001). Sensitivity only approached 95% at 35 umol/l, at which level specificity was low (Table). Two out of 36 (5.6%) patients with nadir creatinine <35 umol/l developed CRI. Multivariate analysis found recurrent UTI (OR 4.733; CI 1.297-17.280) and nadir creatinine >75 umol/l (OR 48.988; CI 4.9-490.11) to be independent risk factors for progression to CRI. Using cut-off values of 35 umol/l and 75 umol/l, patients can be stratified into low-, intermediate- and high-risk groups, with development of CRI in 5.3%, 28.3% and 100%, respectively (P <0.001). The stage of CKD was higher in higher risk groups.

CONCLUSION

Patients with nadir creatinine >75 umol/l (0.85 mg/dl) should be considered at high risk for CRI, while patients with nadir creatinine ≤35 umol/l (0.4 mg/dl) should be considered low risk. Patients with nadir creatinine between these two values have an intermediate risk of CRI.

Increasing the accuracy of 18F-FDG PET/CT interpretation of "mildly positive" mediastinal nodes in the staging of non-small cell lung cancer

INTRODUCTION

The aim of this study was to identify radiological factors that may reduce false-positive results and increase diagnostic accuracy when staging the mediastinum of patients with non-small cell lung carcinoma (NSCLC).

METHODS

This was a retrospective, interdisciplinary, per-node analysis study. We included patients with NSCLC and mediastinal nodes with an SUV max in the range of 2.5-4.0 on PET-CT. We hypothesized that the greatest number of false positive cases would occur in this cohort of patients.

RESULTS

A total of 92 mediastinal lymph nodes were analyzed in 44 patients. Mediastinal disease (N2/N3) was histologically confirmed in 15 of 44 patients and in 34 of 92 lymph nodes; positive predictive value of 37% and false positive rate of 63%. Lymph node SUV max, tumor size, ratio of node SUV max to tumor SUV max (SUVn/SUVp), and ratio of node SUV max to node size (SUV n/SADn) were significantly higher in true positive cases. Using a threshold of 0.3 for SUV node/tumor and 3 for SUV node/size yielded sensitivities of 91% and 71% and specificities of 71% and 69% respectively for the detection of mediastinal disease. Using both ratios in combination resulted in a sensitivity of 65% and a specificity of 88%. Concurrent benign lung disease was observed significantly more frequently in false-positive cases.

CONCLUSION

SUVn/SUVpt and SUVn/SADn may be complimentary to conventional visual interpretation and SUV max measurement in the assessment of mediastinal disease in patients with NSCLC.