CTIM-01. TITLE: PHASE 1B STUDY OF AVELUMAB AND WHOLE BRAIN RADIOTHERAPY (WBRT) IN PATIENTS WITH LEPTOMENINGEAL DISEASE (LMD): PRELIMINARY RESULTS

BACKGROUND

LMD from systemic cancer has a dismal prognosis with median survivals of 8-10 weeks. A phase 2 trial of PD-1 inhibitor monotherapy in LMD showed median overall survival (OS) of 3.6 months (Brastianos P et al., 2020). We determined the safety/efficacy of avelumab, a PD-L1 inhibitor with WBRT in patients with LMD (NCT0371768). This combination can treat the tumor directly and increase BBB permeability (Li, 2003; Nordal, 2005) allowing the increased egress of activated T cells into the meninges/CSF.

METHODS

Patients received concurrent avelumab 800 mg IV q2 weeks for ≤ 5 cycles (unless PD or unacceptable toxicity) with WBRT 3000 cGy in 10 fractions. Primary endpoints are safety/DLTs and OS at 3 months. Secondary endpoints are CSF T-cell/cytokine profiles (scRNAseq, phosophoproteomics etc.).

RESULTS

A total of 15 patients (7 breast, 7 lung & 1 other) were enrolled (n = 13 F, ages 32-79). Pts receiving anti-PD-1/PD-1L/PD-L2/CD137,CTLA-4 therapy ≤ 6 months prior were excluded. Three of 15 patients had grade 3/4 AEs (diarrhea, lymphopenia, decreased WBC count in 3 patients). Seven patients (50%) were alive at 3 or 6 months. The estimated median follow up in 14 patients is 4.75 months (range, 0.92 – 30.05 months, 95% CI is 1.32 ~ 19.82). The median PFS is 3.75 months (95% CI = 0.85-15.16) and median OS is 6.89 months (95% CI = 1.18-14.7).

CONCLUSIONS

The combination of avelumab and WBRT is safe, well tolerated, and demonstrates encouraging activity in patients with LMD with an OS that is longer than other published series. Multiple platform interrogation of CSF (analysis underway) will determine mechanisms of LMD therapeutic/resistance effects.

TMIC-53. DEVELOPMENT OF A GEO-TAGGED TUMOR SAMPLE REGISTRY; LINKAGE OF TUMOR SAMPLE LOCATION TO IMAGING CHARACTERISTICS

Background

Significant intra- and inter-heterogeneity exists in gliomas. This provides clinical, radiological, diagnostic, and treatment challenges. To date, there have been few efforts to comprehensively catalog information obtained in the operating room that spatially links neuro-navigation localization to imaging characteristics, gross intraoperative visual findings, and pathological/molecular features. The value of this spatial localization is probably greatest in high grade gliomas, which have been demonstrated to have intra-tumoral histological and genetic/epigenetic heterogeneity.

METHODS

An IRB-approved institutional registry of patients undergoing clinically-indicated surgery with use of an image-guidance system (IGS) was launched in November 2019 and as of June 1, 2022 includes nearly 500 patients, of which 243 were diagnosed with gliomas. Intraoperatively, locations within the gross tumor or tumor-infiltrated brain were sampled at each surgeon’s discretion, and each sample was linked to their precise location with the IGS system (“geo-tagged”). The registry includes information regarding surgeon; anesthesia technique; use of intraoperative tumor fluorescence; tumor location and volume; pathologic diagnosis and molecular features, and sample number.

RESULTS

Of 243 gliomas, 26 were low grade and 217 were high grade with 174 being glioblastoma. For enhancing tumors, volume of enhancement ranged from 0.31 to 127.0 cm3 with an average of 22.9 cm3. Tumors were widely distributed throughout the cerebrum with 133 left-sided tumors, 110 right-sided and 32 spanning multiple lobes or deep subcortical structures including the brainstem. 51% of surgeries were under awake anesthesia, and 40% were performed using fluorescence guidance. The average number of navigation image-linked samples collected per tumor was 3.67; 3.48 in low grade gliomas, and 3.69 in high grade gliomas. Samples are archived in frozen and/or formalin-fixed, paraffin-embedded formats for future research.

CONCLUSION

This registry provides the foundation for correlation of imaging, intraoperative findings, and pathology in brain tumors, and it will support detailed laboratory/translational investigations addressing tumor heterogeneity.

SURG-35. INTRACRANIAL MYXOID MESENCHYMAL TUMOR WITH EWSR1-ATF1 GENE FUSION

Intracranial myxoid mesenchymal tumors (IMMT) carrying an EWSR1-CREB gene family fusion are extremely rare and have only been identified in ten relatively recent reported cases. There is some question as to whether this is a novel entity, or a myxoid variant of angiomatoid fibrous histiocytoma (AFH), given certain histopathological similarities. Despite these similarities, the increasing number of cases reported appear to demonstrate clear histological differences that indicate IMMTs are a distinct and novel entity. Previous reports have focused on histological analysis but have lacked detailed long-term clinical follow-up and recommendations regarding treatment approach. In this case, we describe a 48-year-old female who presented with a left intraventricular mass that was identified histologically as an IMMT with an EWSR1-ATF1 gene fusion. Following initial resection, the tumor demonstrated local recurrence. Repeat resection was performed followed by immediate demonstration of local, as well as distant, tumor recurrence. Subsequent histological analysis of the tumor demonstrated a myxoid mesenchymal tumor clearly distinct from AFH. Fractionated stereotactic radiation therapy was administered following the second resection and tumor control was achieved at 1 year. This case is particularly remarkable as it is only the second reported IMMT case to occur in a middle-aged adult, with all other cases occurring in children or young adults. The two middle-aged adult cases share striking similarities in clinical presentation, including a history of breast cancer. Our findings indicate that an intracranial myxoid mesenchymal tumor is a novel and rare entity that may demonstrate rapid local and distant recurrence. Given the aggressive recurrence seen with the presented case, we recommend the treatment plan to be surgical resection followed by adjuvant radiation therapy to maintain tumor control.

Antifungal step-down therapy based on hospital intravenous to oral switch policy and susceptibility testing in adult patients with candidaemia: a single centre experience

AIMS

Echinocandins are recommended for the treatment of candidaemia in moderately severe to severely ill patients. Step-down or de-escalation from echinocandin to fluconazole is advised in patients who are clinically stable but data in relation to step-down therapy are sparse. Using our hospital intravenous to oral switch therapy (IVOST) policy to guide antifungal de-escalation in patients with candidaemia, we aimed to determine what proportion of patients are de-escalated to fluconazole, the timescale to step-down, associated reduction in consumption of echinocandins and antifungal cost savings.

METHODOLOGY

Patients with candidaemia were followed from April 2011 to March 2013.

RESULTS

A total of 37 episodes of candidaemia were documented during the study period. Twenty-seven patients were commenced on an echinocandin or voriconazole and 19 (70.3%) were de-escalated to fluconazole based on the IVOST policy. The mean and median number of days to de-escalation of therapy was 4.6 and 5 days, respectively. One patient whose therapy was de-escalated relapsed. The overall 30 day crude mortality was 37.1%. The step-down approach led to significant saving in antifungal drug cost of £1133.88 per candidaemic episode and £2208.08 per de-escalation.

CONCLUSION

Implementation of IVOST policy led to streamlining of antifungal therapy.

Good interobserver and intraobserver agreement in the evaluation of the new ILAE classification of focal cortical dysplasias

PURPOSE

An International League Against Epilepsy (ILAE) consensus classification system for focal cortical dysplasias (FCDs) has been published in 2011 specifying clinicopathologic FCD variants. The aim of the present work was to microscopically assess interobserver agreement and intraobserver reproducibility for FCD categories among an international group of neuropathologists with different levels of experience and access to epilepsy surgery tissue.

METHODS

Surgical FCD specimens covering a broad histopathology spectrum were retrieved from 22 patients with epilepsy. Three surgical nonepilepsy specimens served as controls. A total of 188 slides with routine or immunohistochemical stainings were digitalized with a slide scanner to allow Internet-based microscopy review. Nine experienced neuropathologists were invited to review these cases twice at a time gap of 3 months and different orders of case presentation. The 2011 ILAE FCD consensus classification served as instruction. Kappa analysis was calculated to estimate interobserver and intraobserver agreement levels. In a third evaluation round, 21 additional neuropathologists with different experience and access to epilepsy surgery reviewed the same case series.

KEY FINDINGS

Interobserver agreement was good (κ = 0.6360), with 84% consensus of diagnoses during the first evaluation (21 of 25 cases). Kappa values increased to 0.6532 after reevaluation, and consensus was obtained in 24 (96%) of 25 cases. Overall intraobserver reproducibility was also good (κ = 0.7824, ranging from 0.4991 to 1.000). Fewest changes in the classification were made in the FCD type II group (2.2% of 225 original diagnoses), whereas the majority of changes occurred in FCD type III (13.7% of 225 original diagnoses). In the third evaluation round, interobserver agreement was reflected by the level of experience of each neuropathologist, with κ values ranging from moderate (0.5056; high level of experience >40 cases/year) to low (0.3265; low level of experience <10 cases/year).

SIGNIFICANCE

Our study achieved a good and reliable interobserver agreement among the group of expert neuropathologists originally involved in the ILAE FCD consensus classification system. Intraobserver reproducibility in this group was even more robust. These results showed considerable improvement compared to a previous study evaluating the 2004 Palmini FCD classification. Agreement levels were lower in our second group of neuropathologists and were related to their level of access and experience with epilepsy surgery specimens. These results suggested that the more precise ILAE definition of FCD histopathology patterns improves operational procedures in the diagnosis of FCDs. On the other hand, microscopic assessment of FCD is a challenge and requires sustained experience and teaching. The virtual slide review system allowed testing of this hypothesis and reached a widespread group of participating colleagues from different centers all over the world. We propose to further use this tool as a teaching device and also to address other epilepsy-associated entities still difficult to classify such as hippocampal sclerosis, long-term epilepsy-associated tumors, or mild malformations of cortical development (mMCDs), which were not yet covered by current ILAE classification systems.

Association between endometritis diagnosis using a novel intravaginal device and reproductive performance in dairy cattle

Endometritis reduces reproductive performance in dairy cattle. Diagnosis of endometritis is undertaken using a variety of techniques including vaginoscopy, manual examination, cytology and ultrasonography. The current studies compared a novel test device ("metricheck") that is inserted into the vagina with vaginoscopy and then examined the relationship between the metricheck test score at 35 days before the start of the seasonal breeding programme and subsequent reproductive performance. Cows (n = 191; Study 1) with a history of a peripartum disease were examined by both vaginoscopy and the metricheck device and any material viewed within the vagina (using vaginoscopy) or retrieved (by the metricheck device) was scored on a 0 (no material) to 5 (grossly purulent and with an odour) scale. Within each herd the order of examination was randomized with sequentially presented pairs of cows. All cows (n = 2793; Study 2) from nine herds were examined and scored using the metricheck device 35 days before the start of the seasonal breeding programme. All cows were pregnancy tested to determine date of conception. In Study 1, more cows were defined as infected (i.e. score > 1) following metricheck than vaginoscopic examination (60% versus 43%, respectively; P < 0.05) and the level of agreement between the two tests was moderate (kappa = 0.45). The metricheck device had a higher sensitivity, but lower specificity, than vaginoscopy. Endometritis (i.e. score > 1) was detected in 21.2% of cows examined in Study 2. The prevalence of endometritis varied among herds, declined with time postpartum (P < 0.05) and was higher in cows recorded as having a peripartum disease (P < 0.01). Cows diagnosed with endometritis were at higher risk of not being detected in oestrus before the start of breeding (P < 0.01), took longer to be inseminated after the start of the seasonal breeding programme (P < 0.01), had a lower first service conception rate (P < 0.01), had lower 56-day and final pregnancy rates (P < 0.05) and took longer to conceive than cows without endometritis (P < 0.05). It is concluded that examination with the metricheck device is more sensitive in detecting endometritis than vaginoscopy. Diagnosis of endometritis with the metricheck device was associated with poorer subsequent reproductive performance.

Oculoleptomeningeal amyloidosis in a large kindred with a new transthyretin variant Tyr69His

OBJECTIVE

To describe the clinical, radiologic, and pathologic findings of a kindred with oculoleptomeningeal amyloidosis and a newly associated transthyretin mutation.

BACKGROUND

Transthyretin (TTR) amyloidosis can present in the form of oculoleptomeningeal amyloidosis. Clinical features include dementia, seizures, stroke-like episodes, subarachnoid hemorrhage, ataxia, myelopathy, deafness, radiculopathy, and ocular amyloidosis. Eight TTR mutations associated with oculoleptomeningeal amyloidosis have been described.

METHODS

Fourteen individuals from a kindred with oculoleptomeningeal amyloidosis were examined clinically and radiologically. Analysis of the TTR gene was performed. Neuropathologic examination was obtained on the index patient.

RESULTS

Affected individuals had vitreous amyloid, radiculopathy, seizures, stroke-like episodes, encephalopathy, and dementia. Severely affected individuals died by the end of the fifth decade. Leptomeningeal enhancement on contrast MRI and elevated CSF protein were the defining features on investigations. Sequencing of exon 3 in the TTR gene found a base pair substitution at codon 69. This resulted in heterozygosity for normal tyrosine and variant histidine (ATTR Tyr69His) in affected family members. Domino liver transplantation was attempted as treatment for one family member.

CONCLUSIONS

The ATTR Tyr69His mutation is associated with oculoleptomeningeal amyloidosis. Expression of the genotype is variable. This has implications for treatment of affected individuals and counseling of family members. Efficacy of liver transplantation in patients with oculoleptomeningeal amyloidosis remains unknown. The authors advocate the investigation of liver transplantation in patients with severe symptoms due to oculoleptomeningeal amyloidosis.

Progressive supranuclear palsy diagnosis and confounding features: report on 16 autopsied cases

We evaluated 16 (15 men, 1 woman) autopsy-verified progressive supranuclear palsy (PSP) cases during 31 years (1969-2000) for clinical diagnosis and the course of the disease. The onset was gait difficulty or postural instability in 9 (56.3%), general motor slowing in 3 (18.8%), and tremor in 2. One case had onset with cognitive decline and 1 as hemidystonia. Four cases had supranuclear ophthalmoplegia (SNO) at the first assessment and were diagnosed as PSP. By last assessment, PSP diagnosis was made in 4 additional cases, but in 8 (50%) who never manifested ophthalmoplegia (mean 9.8 years after onset), PSP diagnosis was not made. Other manifestations included bulbar symptoms in 13 (81.3%), and cognitive impairment in 10 (62.5%) during the course of illness. Fifteen cases received levodopa, amantadine, anticholinergics, dopamine agonists, and selegiline in different combinations with symptomatic benefit in 9 of 15 (60%). Five had some improvement on levodopa alone and 3 showed more improvement when a dopamine agonist was added to levodopa. In general, the benefit was minimal and occurred only early in the course of illness. The mean age at onset was 63.7 (range, 53-85) years. Mean duration at PSP diagnosis was 4.8 (range, 2-11) years. Mean survival was 8.6 (range, 3-24) years and mean age at death was 72.3 (range, 60-89) years. When the different diagnostic criteria recommended in the literature were used, the accuracy of clinical diagnosis did not improve substantially.

Clinical-pathological study of levodopa complications

We sought to determine the continued benefit and the pattern of motor complications of long-term levodopa treatment in Parkinson's disease. Patients were evaluated between 1968 and 1996. Only those who had an adequate levodopa trial and in whom autopsy revealed Lewy body Parkinson's disease were included. Total levodopa and mean daily dose were calculated in each case. Dyskinesia, wearing-off and on-off were collectively classified as motor adverse effects and reported as cumulative incidence. Forty-two patients (male, 30; female, 12) with mean 15.9 years of illness and 9.1 years follow-up received on average 500-mg levodopa daily over 9.8 years. Seventeen of 21 patients assessed during the last 18 months of life reported some motor benefit. Adverse effects were seen in 71.4% of patients. The most common was dyskinesia, in 61.9%; wearing-off in 35.7%; and on-off in 16.7% of patients. The earliest adverse effect was dyskinesia and the last to emerge was on-off. Isolated dyskinesia was seen in 35.7% and wearing-off in 7.1% of patients; 15.5% of patients developed dyskinesia after 2.6 years and 31% after 6.4 years on levodopa. We concluded that levodopa benefit declined and adverse effects increased with time. Dyskinesia was the earliest and the most common isolated adverse effect.

Is levodopa toxic to human substantia nigra?

Levodopa (LD) is the most effective drug for symptomatic control of Parkinson's disease, but has been suspected to be toxic to substantia nigra (SN) dopaminergic neurons. Tissue culture and animal studies of LD toxicity have produced contradictory evidence, and one study reported that a human subject exposed to a large cumulative dose (cd) of LD over 4 years had no evidence of SN damage. We report the cases of five patients, each of whom received a large cd of LD over a long period. Fluorodopa positron-emission tomography performed in one case indicated parkinsonism. Autopsies in two cases indicated a normal SN in one and a hypopigmented SN with normal cell complement in the other. Three patients had essential tremor, one had nonprogressive parkinsonism, and one had dopa-responsive dystonia. LD (without decarboxylase inhibitor) was administered over 21 years (cd = 21.99 kg), 9 years (cd = 6.6 kg), 26 years (cd = 18.7 kg), 11 years (cd = 3 kg), and 26 years (cd = 23.93 kg), respectively. None of the patients with essential tremor developed clinical features of parkinsonism that indicated significant SN damage, and one had a normal SN at autopsy. The parkinsonian patient displayed no detectable acceleration of disease process, and the patient with dopa-responsive dystonia had a normal complement of SN neurons at autopsy. We conclude that LD, administered at a dose commonly used for treating Parkinson's disease, was not toxic to SN neurons in these cases.

A novel derivatization of ethylene glycol from human serum using 4-carbethoxyhexafluorobutyryl chloride for unambiguous gas chromatography-chemical ionization mass spectrometric identification and quantification

Ethylene glycol poisoning is a common problem and identification of ethylene glycol in serum is important for both medical and legal purposes. Other glycols like propylene glycol, 2,3-butanediol, and diethylene glycols are also abused. Common derivatization techniques to form cyclic ester of ethylene glycol work only for 1,2-diols and cannot derivatize other glycols like diethylene glycol. The authors describe novel derivatization technique of ethylene glycol (Molecular weight 62) using 4-carbethoxyhexafluorobutyryl chloride that produces a distinct protonated molecular ion peak at m/z 563 in chemical ionization mode, thus aiding in unambiguous confirmation of ethylene glycol. The authors' novel derivatization technique is not limited to 1,2-diols and can derivatize any glycol. It yields less volatile derivatives than any conventional derivatives and is free from interference from the serum matrix. Moreover, those glycols produce distinctively different mass spectra compared to ethylene glycol. Quantitation of ethylene glycol can be easily achieved by using 1,2-butanediol as an internal standard. The assay showed a within run and between run precision of 6.7% and 8.2% and a linearity from 1.1-36.1 mmol/L (70-2,240 micrograms/mliters) of serum ethylene glycol concentration.