Interrater reliability of Brain Tumor Reporting and Data System (BT-RADS) in the follow up of adult primary brain tumors: a single institution experience in Italy

Background

In 2018, a new system was proposed for classifying and reporting post-treatment adult brain tumor on magnetic resonance imaging, named as Brain Tumor Reporting and Data System (BT-RADS), that needs a validation by means of agreement studies.

Methods

A retrospective study was designed with the aim of identifying contrast-enhanced magnetic resonance imaging (MRI) of adult patients on follow-up for primary brain tumor at Fondazione Policlinico Campus Bio-Medico. Four radiologists (2 radiology residents, 1 general radiologist, 1 neuroradiologist) read and scored each study using the BT-RADS scoring tool, blinded to the MRI original report. Interobserver agreement and Fleiss' k were calculated to assess the level of diagnostic agreement. It was assessed how many times the assignment of different scoring of BT-RADS would have led to a different patient management.

Results

The total number of patients included in the study was 23 with 147 MRIs and a total of 588 BT-RADS scores retrospectively evaluated. The two most frequent tumor types were astrocytoma grade 4 (62%) and oligodendroglioma grade 3 (21%). The overall agreement rate for all 4 radiologists was 82% with a Fleiss' k of 0.70. The overall agreement rate between general radiologist and neuroradiologist was 91% with a Fleiss' k of 0.86. The overall agreement rate between 2 radiology residents and neuroradiologist was 80% with a Fleiss' k of 0.66. Astrocytoma grade 3 (k: 0.51) and oligodendroglioma grade 2 (k: 0.32) showed a poor agreement while higher values of agreement were found for astrocytoma grade 4 (k: 0.70), astrocytoma grade 2 (k: 0.78) and oligodendroglioma grade 3 (k: 0.78). All the radiologists agreed on BT-RADS assignment in 70% patients, three radiologists agreed in 17% and two radiologists agree in 13%. In no cases there was a complete disagreement among the readers. In 18% of cases the discrepancy in the estimated BT-RADS would have led to a different follow-up management.

Conclusions

BT-RADS can be considered a valid tool for neuroradiologists and radiologists even with little experience in the interpretation of patients' images during follow-up for adult primary brain tumors supporting standardized interpretation, reporting and clinical management.

SYST-07. PILOT STUDY UTILIZING THE HDAC INHIBITOR BELINOSTAT WITH CHEMORADIATION FOR NEWLY-DIAGNOSED GLIOBLASTOMA

PURPOSE

Glioblastomas (GBMs) are highly aggressive brain tumors with poor prognosis. Belinostat is a histone deacetylase inhibitor with blood–brain barrier permeability, anti-GBM activity, and potential to enhance chemoradiation. This clinical trial sought to determine a tolerable dose of concurrent belinostat and assess the clinical efficacy of combining this drug with standard-of-care therapy.

METHODS

13 patients each were enrolled in control and belinostat cohorts. The belinostat cohort was given a belinostat regimen (500-750mg/m2 1x/day x 5 days) every 3 weeks (weeks 0, 3, and 6 of RT). All patients received standard temozolomide and radiation therapy (RT). Patient outcomes included progression-free survival, overall survival (OS), and analysis of recurrence pattern of the recurrent gross tumor volume (rGTV).

RESULTS

Belinostat at 750 mg/m2 produce dose-limiting toxicities (DLTs) in 2 of 3 patients while belinostat at 500 mg/m2 did not result in DLTs. Median OS was 18.5 months for the belinostat cohort and 15.8 months for the control cohort (p=0.53). The rGTVs in the control cohort occurred in areas that received higher radiation doses than that in the belinostat cohort. For those belinostat patients that experienced out-of-field recurrences, tumors were detectable by spectroscopic MRI (sMRI) before RT. In particular, one belinostat patient had an IDH-mutant GBM that had an extraordinary response to therapy with significant shrinkage of enhancing tumor much greater than expected.

CONCLUSION

Belinostat given concurrently at 500 mg/m2 is well-tolerated. While median OS was not significantly increased for the belinostat cohort, recurrence analysis suggests better in-field control with belinostat, suggesting a radio-sensitizing effect. This study suggests that belinostat can act as a synergistic therapeutic agent for GBMs that may be further enhanced by sMRI-guided RT and may be particularly effective against IDH mutant tumors. A trial is currently in development using belinostat with sMRI-guided RT for IDH-mutant high-grade gliomas.

Hirayama-like disease in the thoracic spine

Hirayama disease is a cervical flexion myelopathy that typically causes upper extremity weakness in young male patients. We present two male patients (age 15 and 29) with MRI findings of thoracic ligamentous laxity similar in appearance to Hirayama disease. However, patients presented with atypical symptoms, specifically back pain and paresthesia of the upper and/or lower extremities, likely correlating to the abnormal thoracic spinal levels involved. Flexion/extension MRI sequences demonstrated the forward displacement of the dorsal dura and compression the thoracic cord with prominence of the posterior epidural space and venous plexus. Follow-up MRAs were negative for a spinal vascular malformation. Patients were managed conservatively with no surgical intervention. Clinical history, thoracic MRI, and follow-up flexion and angiographic imaging sequences may help confirm a diagnosis of Hirayama-like thoracic ligamentous laxity.

Development and external validation of a prognostic tool for COVID-19 critical disease

Background

The rapid spread of coronavirus disease 2019 (COVID-19) revealed significant constraints in critical care capacity. In anticipation of subsequent waves, reliable prediction of disease severity is essential for critical care capacity management and may enable earlier targeted interventions to improve patient outcomes. The purpose of this study is to develop and externally validate a prognostic model/clinical tool for predicting COVID-19 critical disease at presentation to medical care.

Methods

This is a retrospective study of a prognostic model for the prediction of COVID-19 critical disease where critical disease was defined as ICU admission, ventilation, and/or death. The derivation cohort was used to develop a multivariable logistic regression model. Covariates included patient comorbidities, presenting vital signs, and laboratory values. Model performance was assessed on the validation cohort by concordance statistics. The model was developed with consecutive patients with COVID-19 who presented to University of California Irvine Medical Center in Orange County, California. External validation was performed with a random sample of patients with COVID-19 at Emory Healthcare in Atlanta, Georgia.

Results

Of a total 3208 patients tested in the derivation cohort, 9% (299/3028) were positive for COVID-19. Clinical data including past medical history and presenting laboratory values were available for 29% (87/299) of patients (median age, 48 years [range, 21–88 years]; 64% [36/55] male). The most common comorbidities included obesity (37%, 31/87), hypertension (37%, 32/87), and diabetes (24%, 24/87). Critical disease was present in 24% (21/87). After backward stepwise selection, the following factors were associated with greatest increased risk of critical disease: number of comorbidities, body mass index, respiratory rate, white blood cell count, % lymphocytes, serum creatinine, lactate dehydrogenase, high sensitivity troponin I, ferritin, procalcitonin, and C-reactive protein. Of a total of 40 patients in the validation cohort (median age, 60 years [range, 27–88 years]; 55% [22/40] male), critical disease was present in 65% (26/40). Model discrimination in the validation cohort was high (concordance statistic: 0.94, 95% confidence interval 0.87–1.01). A web-based tool was developed to enable clinicians to input patient data and view likelihood of critical disease.

Conclusions and relevance

We present a model which accurately predicted COVID-19 critical disease risk using comorbidities and presenting vital signs and laboratory values, on derivation and validation cohorts from two different institutions. If further validated on additional cohorts of patients, this model/clinical tool may provide useful prognostication of critical care needs.

CTNI-13. UPDATES ON CLINICAL OUTCOMES AND TUMOR RECURRENCE PATTERNS OF A HUMAN PILOT STUDY ASSESSING EFFICACY OF BELINOSTAT (PXD-101) COMBINING WITH CHEMORADIATION IN TREATING GLIOBLASTOMA

INTRODUCTION

Glioblastoma (GBM) is highly aggressive with poor prognosis. Belinostat is a histone deacetylase inhibitor with blood–brain barrier permeability that has anti-GBM activity and may enhance effects of chemoradiation. Our institution conducted a clinical trial evaluating clinical efficacy of belinostat with standard-of-care therapy for GBMs.

METHODS

13 and 14 patients were enrolled into cohort 1 (c1, control) or cohort 2 (c2, belinostat) with 12 in each group with sufficient follow-up MRIs for recurrence analysis. All patients received concurrent, adjuvant temozolomide and focal radiation therapy (RT). For c2 patients, the belinostat regimen (500-750mg/m2 1x/day x 5 days) was given over three cycles every 3 weeks (weeks -1, 2, and 5 of RT). RT margins of 5–10 mm and 3 mm were added to generate clinical tumor volumes and planning target volumes (PTVs). PTV1 (based on FLAIR MRI) and PTV2 (based on CE-T1w MRI) received 51 and 60 Gy, respectively, over 30 fractions. Volume at initial recurrence (rGTV) was contoured.

RESULTS

Mean age was 58.3 years for c1 and 51.1 years for c2. Patient/tumor characteristics were similar between cohorts. Median OS were 16.6 and 18.5 months for c1 and c2 (p=0.538), respectively. Average minimum, maximum and mean radiation dose to rGTV was 54.1 Gy, 64.2 Gy and 62 Gy, for c1, and 47.5 Gy, 57.6 Gy and 53.5 Gy, for c2 (p=0.322, 0.088 and 0.071), respectively. The mean overlap between rGTV and PTV1/PTV2 for c1 & c2 were 99.2% & 96.9%/99.8% & 78.7% (p=0.489/0.133), respectively.

CONCLUSION

Median OS was slightly longer for c2 though not statistically significant. rGTV in c1 received higher radiation doses and had more overlap with PTV2 than in c2. Out-of-field recurrence appears more likely in c2 suggesting better infield control with belinostat. This study highlights the potential of belinostat as a synergistic therapeutic agent for GBM treatment.

Impact of Sequencing Radiation Therapy and Immune Checkpoint Inhibitors in the Treatment of Melanoma Brain Metastases

PURPOSE

Melanoma brain metastases (MBM) occur in ∼50% of melanoma patients. Although both radiation therapy (RT) and immune checkpoint inhibitor (ICI) are used alone or in combination for MBM treatment, the role of this combination and how these treatments could best be sequenced remains unclear.

METHODS AND MATERIALS

We conducted a retrospective analysis of patients with resected MBM who underwent treatment with RT, ICI, or a combination of RT and ICI. Among the latter, we specifically investigated the differential gene expression via RNA-sequencing between patients who received RT first then ICI (RT → ICI) versus ICI first then RT (ICI → RT). We used a glycoprotein-transduced syngeneic melanoma mouse model for validation experiments.

RESULTS

We found that for patients with resected MBM, a combination of RT and ICI confers superior survival compared with RT alone. Specifically, we found that RT → ICI was superior compared with ICI → RT. Transcriptome analysis of resected MBM revealed that the RT → ICI cohort demonstrated deregulation of genes involved in apoptotic signaling and key modulators of inflammation that are most implicated in nuclear factor kappa-light-chain-enhancer of activated B cells signaling. In a preclinical model, we showed that RT followed by anti-programmed death-ligand 1 therapy was superior to the reverse sequence of therapy, supporting the observations we made in patients with MBM.

CONCLUSIONS

Our study provides initial insights into the optimal sequence of RT and ICI in the treatment of MBM after surgical resection. Prospective studies examining the best sequence of RT and ICI are necessary, and our study contributes to the rationale to pursue these.

The Brain Imaging Collaboration Suite (BrICS): A Cloud Platform for Integrating Whole-Brain Spectroscopic MRI into the Radiation Therapy Planning Workflow

Glioblastoma has poor prognosis with inevitable local recurrence despite aggressive treatment with surgery and chemoradiation. Radiation therapy (RT) is typically guided by contrast-enhanced T1-weighted magnetic resonance imaging (MRI) for defining the high-dose target and T2-weighted fluid-attenuation inversion recovery MRI for defining the moderate-dose target. There is an urgent need for improved imaging methods to better delineate tumors for focal RT. Spectroscopic MRI (sMRI) is a quantitative imaging technique that enables whole-brain analysis of endogenous metabolite levels, such as the ratio of choline-to-N-acetylaspartate. Previous work has shown that choline-to-N-acetylaspartate ratio accurately identifies tissue with high tumor burden beyond what is seen on standard imaging and can predict regions of metabolic abnormality that are at high risk for recurrence. To facilitate efficient clinical implementation of sMRI for RT planning, we developed the Brain Imaging Collaboration Suite (BrICS; https://brainimaging.emory.edu/brics-demo), a cloud platform that integrates sMRI with standard imaging and enables team members from multiple departments and institutions to work together in delineating RT targets. BrICS is being used in a multisite pilot study to assess feasibility and safety of dose-escalated RT based on metabolic abnormalities in patients with glioblastoma (Clinicaltrials.gov NCT03137888). The workflow of analyzing sMRI volumes and preparing RT plans is described. The pipeline achieved rapid turnaround time by enabling team members to perform their delegated tasks independently in BrICS when their clinical schedules allowed. To date, 18 patients have been treated using targets created in BrICS and no severe toxicities have been observed.

ACTR-70. A MULTISITE CLINICAL TRIAL OF SPECTROSCOPIC MRI-GUIDED RADIATION DOSE ESCALATION IN GLIOBLASTOMA PATIENTS

The standard of care for glioblastoma is neurosurgical resection followed by radiation therapy (RT) and temozolomide (TMZ) chemotherapy. Although RT is effective for glioblastoma, attempts to improve survival using RT dose escalation above 60 Gy have been largely unsuccessful. This may be because prior attempts have been targeted to resection cavity or enhancing tumor, which may not accurately predict areas at highest recurrence risk. To overcome the limitations of standard T1 and T2-weighted MRI in predicting tumor recurrence, we have shown that supplementation with 3D high-resolution spectroscopic MRI (sMRI) identifies actively proliferating tumor beyond areas of T1-enhancement by measuring endogenous metabolites and their ratios. Previously, we demonstrated that the choline to N-acetylaspartate ratio (Cho/NAA) best correlates with tumor cellularity in surgically resected tissue (ρ=0.82, p< 0.001) and, most importantly, areas of sMRI metabolic abnormalities predate disease recurrence in those same areas (Cordova et al, Neuro-Oncology 2016). Therefore, we seek to identify whether sMRI can be used by radiation oncologists to choose the optimal regions to target for RT dose escalation. To assess its feasibility and safety, we developed a web-based imaging platform designed specifically to incorporate sMRI into the RT planning clinical workflow and are using it in a multisite sMRI-guided dose escalation trial (NCT03137888; Emory, Johns Hopkins, U. Miami). Recently, we have completed full enrollment including 30 patients treated with sMRI-guided dose escalated RT across three institutions. We have demonstrated successful integration of sMRI into the RT planning workflow, and we have delivered sMRI-guided dose escalated RT plans to glioblastoma patients without severe adverse events to date. Follow-up data will be analyzed for overall and progression-free survival. Based on the feasibility and safety of this technique in the current trial, we plan to assess the efficacy of sMRI-guided dose-escalated RT on patient outcomes in a NCTN clinical trial.

EXTH-12. RADIATION ENHANCES MELANOMA RESPONSE TO IMMUNOTHERAPY AND SYNERGIZES WITH BENZODIAZEPINES TO PROMOTE ANTI-TUMOR ACTIVITY

Melanoma brain metastases (MBM) occur in ~50% of advanced melanoma patients. It is unclear if systemic therapies synergize with radiotherapy (RT) and what the impact of RT timing has on efficacy. We find that RT followed by ICI (immune checkpoint inhibitors) (RTàICI) improves MBM patient survival compared to other combination strategies, also shown here in a murine melanoma model. RNA-seq of MBM tumors in the RTàICI group exhibit overrepresentation of genes implicated in NFKB signaling. There is also expression of GABAA receptor subunits across both treatment groups. We show that melanoma cells express functional GABAA receptors and that benzodiazepines impair tumor growth. Combination of sub-lethal RT doses with benzodiazepine results in significant ipsilateral and out of field abscopal anti-tumor activity, which is associated with enhanced tumor infiltration with poly-functional CD8 T-cells. This study provides evidence that RT enhances MBM response to ICI and synergizes with benzodiazepines to promote anti-tumor activity.

NIMG-10. BRAIN TUMOR MRI STRUCTURED REPORTING ALLOWS CALCULATION OF INTERRATER AGREEMENT OF PATIENTS REVIEWED AT TUMOR BOARD

INTRODUCTION

Longitudinal imaging evaluation of brain tumor patients with MRI is a challenging endeavor, as there is considerable overlap between imaging findings of tumor progression and treatment related changes. There is felt to be a high degree of variation between individual interpreters, particularly in complex cases. Structured reporting systems, such as the recently described brain tumor reporting and data system (BT-RADS), attempt to maximize consistency between reading radiologists, although how successful they are at achieving this is unknown.

METHODS

Patients with a diagnosis of a primary brain tumor with imaging presented at adult brain tumor board between October 2017 and March 2019 were reviewed. The most recent follow-up MRI was scored on an 8-point scale as described by BT-RADS, ranging from 0 to 4 with increasing suspicion for worsening disease, as described in the original radiologist report. Secondary review of MRI was performed by one of three neuroradiologists routinely participating in brain tumor conference. Interrater agreement between primary and secondary review were calculated using rates of exact agreement and linear weighted kappa.

RESULTS

Of studies reviewed, 270 out of 275 had imaging and reports suitable for repeat structured scoring. Grade 4 astrocytoma (glioblastoma) was the most common diagnosis, followed by grade 2 oligodendroglioma and grade 2 astrocytoma. The overall agreement rate between initial and secondary review was 83.0% with kappa of 0.89 +/- .05. There was perfect agreement on studies with improvement (1a or 1b) with lower levels of agreement (63.6–82.4%) for studies with worsening imaging findings (3a-4).

CONCLUSIONS

Using a structured reporting system to categorize MRIs in brain tumor patients allows for precise characterization of variation between report conclusions on primary and secondary review. Overall agreement is good, but variation rates increase with worsening findings which may be harder to correctly interpret.

ACTR-51. REMARKABLE RESPONSE OF A PATIENT WITH SECONDARY GBM TO A HISTONE DEACETYLASE INHIBITOR

Glioblastomas are highly aggressive, grade IV tumors of glial cells that arise either as de novo primary tumors or as secondary tumors, which malignantly transformed from lower grade gliomas. Secondary glioblastomas have a relatively low incidence making up 5–10% of all glioblastoma diagnoses and tend to occur in younger patients. However, these tumors are still quite aggressive with survival outcomes that do not differ substantially from primary glioblastomas. Secondary glioblastomas also often harbor mutation of isocitrate dehydrogenase (IDH) enzyme, which produces the oncometabolite 2-hydroxyglutarate (2-HG) from alpha-ketoglutarate (α-KG). The accumulation of 2-HG has several downstream effects due to its competitive inhibition of α-KG-dependent enzymes, including epigenetic modification via hypermethylation of histones. Histone deacetylase inhibitors (HDACi) are a class of molecules that inhibit histone deacetylation and have been shown to have anti-tumor effect in part due to this epigenetic modification. Thus, because of their shared targets with regard to histone modification, it is plausible that HDACi could counter the oncometabolite effects of accumulated 2-HG in IDH1 mutant tumors. Since belinostat is a pan-HDACi that has improved blood-brain barrier penetration compared to many other HDACis, we conducted a pilot study that enrolled 15 patients examining its upfront use for the treatment of glioblastomas and found that it was well tolerated. One patient in particular, likely with secondary glioblastoma harboring the typical IDH1 mutation, underwent treatment with standard chemoradiation as well as belinostat on this study. For this case, a remarkable improvement in tumor burden with very significant decrease in enhancing residual tumor and restoration of magnetic resonance spectroscopy (MRS)-detectable metabolism was noted. Furthermore, improved neurocognitition and quality-of-life were also observed in this patient during the 18-month follow-up period. Collectively, these outcomes potentially support the use of belinostat as an adjuvant therapy for patients with secondary glioblastoma that harbor a mutant IDH enzyme.

SURG-31. SPECTROSCOPIC MRI TO GUIDE BIOPSY OF LOWER GRADE GLIOMAS

Primary brain tumors are serious and life-threatening; thus, accurate histopathologic diagnosis is critical for determining the proper clinical treatment regimen. Grade II/III gliomas (lower grade gliomas, or LGGs), including astrocytomas and oligodendrogliomas, are heterogeneous and potentially contain low- and high-grade areas within the same tumor. Therefore, it is critical to target biopsies to the most aggressive portion of the tumor to avoid tumor under-grading and under-treatment. While glioblastomas are typically targeted based on contrast-enhanced MRI, LGGs have little contrast enhancement to define targets for biopsy treatment guidance. Spectroscopic MRI (sMRI) is a high-resolution MRI imaging method which allows for detection of metabolic abnormalities such as choline and NAA in the entire brain without injection of a contrast agent. We have previously evaluated the relationship between sMRI Cho/NAA ratios and tumor infiltration in surgical specimens from high grade gliomas, demonstrating a strong correlation between sMRI results and glioma infiltration. We also used the location information to correlate sMRI data to genetic and histologic biomarkers (such as 1p19q, IDH, and MGMT). An IRB-approved pilot study to obtain sMRI prior to stereotactic biopsy has been done in 20 non-enhancing LGG cases. Patients with a suspected LGG diagnosis underwent sMRI at the time of their surgical planning MRI. sMRI images were then registered to the T1w-CE and T2/FLAIR images and imported into the Stealth neuronavigation system for biopsy planning. We found that all astrocytomas (regardless of grades) showed strongly elevated Cho/NAA, while the LGGs were hardly delineated on T1w and T2/FLAIR. We found that pathology-confirmed grade II oligodendroglioma do not have choline elevation; however, NAA was mildly decreased, myo-inositol was elevated, and creatine (Cr) was mildly elevated. sMRI is a useful tool to improve biopsy targeting in LGG patients by ensuring that the highest risk regions are sampled.

Diffusion Characteristics of Pediatric Diffuse Midline Gliomas with Histone H3-K27M Mutation Using Apparent Diffusion Coefficient Histogram Analysis

BACKGROUND AND PURPOSE

Diffuse midline gliomas with histone H3 K27M mutation are biologically aggressive tumors with poor prognosis defined as a new diagnostic entity in the 2016 World Health Organization Classification of Tumors of the Central Nervous System. There are no qualitative imaging differences (enhancement, border, or central necrosis) between histone H3 wildtype and H3 K27M-mutant diffuse midline gliomas. Herein, we evaluated the utility of diffusion-weighted imaging to distinguish H3 K27M-mutant from histone H3 wildtype diffuse midline gliomas.

MATERIALS AND METHODS

We identified 31 pediatric patients (younger than 21 years of age) with diffuse gliomas centered in midline structures that had undergone assessment for histone H3 K27M mutation. We measured ADC within these tumors using a voxel-based 3D whole-tumor measurement method.

RESULTS

Our cohort included 18 infratentorial and 13 supratentorial diffuse gliomas centered in midline structures. Twenty-three (74%) tumors carried H3-K27M mutations. There was no difference in ADC histogram parameters (mean, median, minimum, maximum, percentiles) between mutant and wild-type tumors. Subgroup analysis based on tumor location also did not identify a difference in histogram descriptive statistics. Patients who survived <1 year after diagnosis had lower median ADC (1.10 × 10^-3mm²/s; 95% CI, 0.90-1.30) compared with patients who survived >1 year (1.46 × 10^-3mm²/s; 95% CI, 1.19-1.67; P < .06). Average ADC values for diffuse midline gliomas were 1.28 × 10^-3mm²/s (95% CI, 1.21-1.34) and 0.86 × 10^-3mm²/s (95% CI, 0.69-1.01) for hemispheric glioblastomas with P < .05.

CONCLUSIONS

Although no statistically significant difference in diffusion characteristics was found between H3-K27M mutant and H3 wildtype diffuse midline gliomas, lower diffusivity corresponds to a lower survival rate at 1 year after diagnosis. These findings can have an impact on the anticipated clinical course for this patient population and offer providers and families guidance on clinical outcomes.

Gliosarcoma: distinct molecular pathways and genomic alterations identified by DNA copy number/SNP microarray analysis

PURPOSE

Gliosarcoma is a histologic variant of glioblastoma (GBM), and like GBM carries a poor prognosis. Median survival is less than one (1) year with less than 5% of patients alive after 5 years. Although there is no cure, standard treatment includes surgery, radiation and chemotherapy. While very similar to GBM, gliosarcoma exhibits several distinct differences, morphologically and molecularly. Therefore, we report a comprehensive analysis of DNA copy number changes in gliosarcoma using a cytogenomic DNA copy number (CN) microarray (OncoScan®).

METHODS

Cytogenomic DNA copy number microarray (OncoScan®) was performed on 18 cases of gliosarcoma. MetaCore™ enrichment was applied to the array results to detect associated molecular pathways.

RESULTS

The most frequent alteration was copy number loss, comprising 57% of total copy number changes. The number of losses far exceeded the number of amplifications (***, < 0.001) and loss of heterozygosity events (***, < 0.001). Amplifications were infrequent (4.6%), particularly for EGFR. Chromosomes 9 and 10 had the highest number of losses; a large portion of which correlated to CDKN2A/B loss. Copy number gains were the second most common alteration (26.2%), with the majority occurring on chromosome 7. MetaCore™ enrichment detected notable pathways for copy number gains including: HOXA, Rho family of GTPases, and EGFR; copy number loss including: WNT, NF-kß, and CDKN2A; and copy number loss of heterozygosity including: WNT and p53.

CONCLUSIONS

The pathways and copy number alterations detected in this study may represent key drivers in gliosarcoma oncogenesis and may provide a starting point toward targeted oncologic analysis with therapeutic potential.

NO synthase 2 (NOS2) deletion promotes multiple pathologies in a mouse model of Alzheimer's disease

Alzheimer's disease is characterized by two primary pathological features: amyloid plaques and neurofibrillary tangles. The interconnection between amyloid and tau aggregates is of intense interest, but mouse models have yet to reveal a direct interrelationship. We now show that NO may be a key factor that connects amyloid and tau pathologies. Genetic removal of NO synthase 2 in mice expressing mutated amyloid precursor protein results in pathological hyperphosphorylation of mouse tau, its redistribution to the somatodendritic compartment in cortical and hippocampal neurons, and aggregate formation. Lack of NO synthase 2 in the amyloid precursor protein Swedish mutant mouse increased insoluble beta-amyloid peptide levels, neuronal degeneration, caspase-3 activation, and tau cleavage, suggesting that NO acts at a junction point between beta-amyloid peptides, caspase activation, and tau aggregation.

Local carboplatin delivery and tissue distribution in livers after radiofrequency ablation

This study investigated the local drug pharmacokinetics of intralesional drug delivery after radiofrequency ablation of the liver. We hypothesized that the tissue architecture damaged by the ablation process facilitates the drug penetration in the liver and potentially enlarges the therapeutic margin in the local treatment of cancer. The delivery rate and tissue distribution of carboplatin, an anticancer agent, released from poly(D,L-lactide-co-glycolide) implants into rat livers after radiofrequency ablation were quantified by atomic absorption spectroscopy. Results showed that carboplatin clearance through blood perfusion was significantly slower in the ablated livers, leading to a more extensive tissue retention and distribution of the drug. The concentration of Pt at the implant-tissue interface ranged from 234 to 1440 microg Pt/(g liver) in the ablated livers over 144 h versus 56 to 177 microg Pt/(g liver) in the normal tissue. The maximum penetration distance at which Pt level reached above 6 microg/g (calculated based on a reported IC90 value for carboplatin) was 8-10 mm and 4-6 mm in ablated and normal liver, respectively. Histological analysis of the necrotic lesions showed widespread destruction of tissue structure and vasculature, supporting the initial hypothesis. This study demonstrated that intralesional drug delivery could provide a sustained, elevated concentration of anticancer drug at the ablation boundary that has the potential to eliminate residual cancer cells surviving radiofrequency ablation.

Effect of fibrous capsule formation on doxorubicin distribution in radiofrequency ablated rat livers

In this study, we report the histological findings of a combined therapy using radiofrequency ablation and intratumoral drug delivery in rat livers, with special attention to wound-healing processes and their effects on drug transport in post-ablated tissue. Doxorubicin-loaded millirods were implanted in rat livers that had undergone medial lobe ablation. Millirods and liver samples were retrieved upon animal sacrifice at time points ranging from 1 h to 8 days. Results demonstrate a clearly defined area of coagulative necrosis within the ablation boundary. The wound-healing response, complete with the appearance of inflammatory cells, neovascularization, and the formation of a fibrous capsule, was also observed. At the 8-day time point, fluorescence imaging analysis showed a higher concentration of doxorubicin localized within the ablation region, with its distribution hampered primarily by fibrous capsule formation at the boundary. Given the variant nature of ablated liver, a mathematical model devised previously by our laboratory describes the data well up to 4 days, but loses reliability at 8 days. These results provide useful mechanistic insights into the wound-healing response after radiofrequency ablation and polymer millirod implantation, as well as the impact this natural corollary has on drug distribution.

Theoretical analysis and experimental evaluation of a Csl(TI) based electronic portal imaging system

This article discusses the design and analysis of a portal imaging system based on a thick transparent scintillator. A theoretical analysis using Monte Carlo simulation was performed to calculate the x-ray quantum detection efficiency (QDE), signal to noise ratio (SNR) and the zero frequency detective quantum efficiency [DQE(0)] of the system. A prototype electronic portal imaging device (EPID) was built, using a 12.7 mm thick, 20.32 cm diameter, Csl(Tl) scintillator, coupled to a liquid nitrogen cooled CCD TV camera. The system geometry of the prototype EPID was optimized to achieve high spatial resolution. The experimental evaluation of the prototype EPID involved the determination of contrast resolution, depth of focus, light scatter and mirror glare. Images of humanoid and contrast detail phantoms were acquired using the prototype EPID and were compared with those obtained using conventional and high contrast portal film and a commercial EPID. A theoretical analysis was also carried out for a proposed full field of view system using a large area, thinned CCD camera and a 12.7 mm thick CsI(TI) crystal. Results indicate that this proposed design could achieve DQE(0) levels up to 11%, due to its order of magnitude higher QDE compared to phosphor screen-metal plate based EPID designs, as well as significantly higher light collection compared to conventional TV camera based systems.

Sonographic sign of intermittent dilatation of the renal collecting system in 10 patients with vesicoureteral reflux

PURPOSE

Renal sonography is an accepted primary imaging modality for evaluating the pediatric urinary tract. We report a new sonographic finding associated with vesicoureteral reflux (VUR).

METHODS

Ten patients underwent sonographic evaluation of the kidneys and were noted to have intermittent renal collecting system dilatation that expanded and contracted during real-time scanning. These patients were further evaluated with voiding cystourethrography.

RESULTS

All 10 patients were proven to have VUR on the side of the sonographic abnormality. Four patients had bilateral VUR for a total of 14 refluxing renal units. Of these 14 renal units, 1 was sonographically normal. Five of the 14 renal units had grade V VUR that required surgical reimplantation of the ureter.

CONCLUSIONS

This new finding of intermittent renal collecting system dilatation may become an important predictor of VUR. The finding warrants further evaluation even when detected in patients not suspected of having VUR who are undergoing renal sonography for other reasons.

Enhancement of female esophageal and tracheoesophageal speech

Qi [J. Acoust. Soc. Am. 88, 1228-1235 (1990)] has demonstrated that (1) linear predictive (LP) methods can be used to separate vocal tract transfer functions from source functions of vowels produced by alaryngeal talkers and that (2) vowels synthesized with reconstructed transfer functions and totally synthetic voicing excitation sources have improved source-related properties over those present in the original vowels. Here, an extension of this work which is directed to the general goal of developing systems (devices) to enhance the quality of alaryngeal speech is reported. The specific goal of the present project was to determine whether speech, i.e., words spoken by female esophageal and tracheoesophageal talkers, could be enhanced by means of LP-based analysis and synthesis methods. Words spoken by four female alaryngeal talkers were analyzed and synthesized. A perceptual evaluation was completed to permit the quality of the synthetic and the original words to be compared. Listeners generally preferred to listen to the synthesized words, indicating that alaryngeal speech enhancement was accomplished.

Characteristics of voicing source waveforms produced by esophageal and tracheoesophageal speakers

Voicing source waveforms produced by 10 laryngectomized esophageal speakers, 12 laryngectomized tracheoesophageal speakers, and 10 age-matched, normal male speakers were obtained by inversely filtering flow functions recorded with a circumferentially vented mask. The data from these speakers was used to evaluate differences in source signal properties on a group basis. In a second analysis source signals produced by a single laryngectomized individual, capable of producing esophageal and tracheoesophageal speech in a highly proficient manner, were analyzed and compared. The overall results of this project provide an initial and novel description of voicing source signals produced by esophageal and tracheoesophageal speakers. The characteristics of these signals appear to be highly variable, particularly in comparison with the homogeneous pattern of source waves produced by age-matched, normal speakers. This initial description of voicing source signals produced by alaryngeal speakers is generally supportive of the hypothesis of differences in source properties among normal, esophageal, and tracheoesophageal voices.

Minimizing the effect of period determination on the computation of amplitude perturbation in voice

Current methods of computing amplitude perturbation present in human voices depend upon being able to accurately determine fundamental period. In this paper, two methods of estimating the amplitude perturbation present in human voices, which do not depend on accurate determination of the boundaries between fundamental periods, are described. In both of these methods, amplitude perturbation is computed as the variance of an ensemble of periods calculated after these periods have been aligned in time. In one method, time alignment is accomplished using zero-phase transformation. In the second method, an unconstrained dynamic programming procedure is used. The accuracy of estimating amplitude perturbation by these two methods is evaluated using synthetic and natural voice signals and is also compared with an estimation using zero-padding based time alignment. The unconstrained dynamic programming method is shown to provide accurate estimation of voice amplitude perturbation over a variety of signal conditions.

A homomorphic method for measuring secondary amplitude modulation

A homomorphic processing, software implemented method for measuring secondary amplitude modulation (AM) is described. The accuracy of measurement of this method was tested on a series of synthetically produced AM and vowel signals. The homomorphic method provided highly accurate measurement of modulation frequency and modulation index.

Serum and ascitic fluid levels of interleukin-1, interleukin-6, and tumor necrosis factor-alpha in patients with ovarian epithelial cancer

BACKGROUND

Recent studies have shown that multiple cytokines are secreted by ovarian epithelial cancer cells. Previous studies have shown that the cancer cell lines secrete macrophage colony-stimulating factor (M-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 (IL-1), interleukin-6 (IL-6), and transforming growth factor-alpha (TGF-alpha). Concomitantly, the serum levels of one of the growth factors (M-CSF) was found to be significantly elevated in patients with primary ovarian cancer and in second-look patients. The authors evaluated the serum levels of IL-1 alpha, IL-1 beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in patients with primary ovarian epithelial cancer. These levels were then compared with cytokine concentration found in normal peritoneal fluid.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of cytokines in normal peritoneal fluid, ascites, and serum.

RESULTS

In serum, TNF-alpha and IL-6 were significantly increased in primary ovarian cancer patients when compared with control subjects (P < 0.0001 for both cytokines). TNF-alpha and IL-6 were also significantly higher than the levels found in second-look patients (P < 0.007 for TNF-alpha, and P = 0.0002 for IL-6). The levels of IL-1 alpha and beta were not elevated in ovarian cancer. TNF-alpha in the ascites was higher when compared with normal peritoneal fluid and was statistically significantly different when a cut-off point between 71-110 pg was selected (P < 0.005). The levels of IL-6 in ascites from patients with primary ovarian cancer also showed a marked increase (P < 0.0001) when compared with peritoneal fluid from control subjects.

CONCLUSIONS

Levels of IL-1, IL-6, and TNF-alpha were determined in normal peritoneal fluid, ovarian malignant ascites, normal serum, and serum from patients with ovarian cancer. This study showed that the patients with ovarian cancer have elevated levels of IL-6 and TNF-alpha in serum and ascitic fluid. A larger study would help in evaluating the potential use of cytokines as tumor markers in ovarian cancer.

The apical oblique view of the clavicle: its usefulness in neonatal and childhood trauma

We analyzed clavicular radiographs of 26 patients with a history of trauma. The apical oblique projection of the clavicle was obtained with the injured side of the patient angled 45 degrees towards the X-ray tube and a 20 degrees cephalad angulation of the X-ray beam. This view proved to be more informative than the routine apical anteroposterior projection. It is especially effective in detecting nondisplaced fractures of the middle third of the clavicle in neonates and children. To verify our findings, we obtained apical anteroposterior and oblique radiographs of a specimen adult clavicle. On the oblique view with 20 degrees cephalad angulation of the X-ray beam, the measurements of the projected lengths of the anatomical specimen, especially those of the middle portion of the clavicle, were very close to the corresponding anatomical lengths.

Strategies to manage the post-MI patient with ventricular arrhythmias

The occurrence of late ventricular arrhythmias after acute myocardial infarction is common. The available data do not support the treatment of asymptomatic premature ventricular complexes or asymptomatic non-sustained ventricular tachycardia after acute myocardial infarction. Signal-averaged electrocardiograms, perhaps in combination with Holter recording and measurements of left ventricular function show promise as potential markers of risk for subsequent sudden death or sustained ventricular tachycardia. Nevertheless, the appropriate treatment of any high-risk but asymptomatic subset of patients has not been established. Patients experiencing sustained ventricular tachycardia after acute myocardial infarction and survivors of late ventricular fibrillation are at high risk of early cardiac mortality and require aggressive treatment which may consist of serial electrophysiologic testing to evaluate drug therapy, arrhythmia surgery, or placement of an automatic implantable cardioverter defibrillator.

Tone in Thai alaryngeal speech

The perception and production of linguistic tone was investigated in utterances spoken by Thai alaryngeal speakers. Thai is a tone language with five phonemic tones. High-quality tape recordings of five monosyllabic words produced by 2 esophageal, 1 electrolaryngeal, and 5 normal, native Thai speakers were subjected to perceptual and acoustic analysis. Results from the phonemic identification tests indicated that tones produced by alaryngeal speakers were not only perceived at much lower levels of accuracy than those produced by normal speakers, but the patterns of tonal confusions for alaryngeal speakers were also dissimilar to those for normal speakers. Results from fundamental frequency (Fo) analysis revealed that the performance deficit of alaryngeal speakers could be related to specific characteristics of their Fo contours. Findings are interpreted to highlight the importance of (a) language, (b) type of prosody, (c) form of alaryngeal speech, and (d) Fo level and direction on linguistic assessments of Fo control in alaryngeal speech.

Voice onset time in Thai alaryngeal speech

The perception and production of voicing contrast was investigated in utterances spoken by Thai alaryngeal speakers. Thai exhibits a three-category voicing distinction for bilabial /b, p, ph/ and alveolar /d, t, th/ stops and a two-category distinction for velar [k, kh] stops. Voice onset time (VOT) was measured in word-initial stops of words produced in isolation by 2 Thai esophageal speakers and 1 Thai user of an electronic artificial larynx. These measurements were compared with published VOT values for the same words spoken by 5 normal Thai speakers. Both esophageal speakers were capable of signaling voicing distinctions for /b, d/ and /p, t, k/. The electrolaryngeal speaker was able to signal /p, t, k/ only. Thai alaryngeal speakers were generally unsuccessful in signaling /ph, th, kh/. A cross-linguistic comparison to VOT in English suggests that no more than two voicing categories can be distinguished in these two forms of alaryngeal speech. Findings are interpreted to illustrate that the realization of stop voicing contrasts in alaryngeal speech depends on the number of voicing categories in a language, the relative positions of the voicing categories on the VOT continuum, and the form of alaryngeal speech.

Infantile hemangioendothelioma of heterotopic intrathoracic liver associated with diaphragmatic hernia

An autopsy of a six-hour-old term neonate, who died during surgery for repair of a left diaphragmatic hernia, revealed an infantile hemangioendothelioma type I arising in a heterotopic lobe of liver in the left thorax. The upper pole of the tumor was attached by fibrovascular tissue to the lower lobe of the left hypoplastic lung. A pedicle attached to the lower pole of the heterotopic liver pierced through the diaphragm to the left lobe of the normal liver. This case is an example of an unusual association of congenital malformation and putative neoplasm.

The air bronchogram: sonographic demonstration

A new sonographic pattern of pulmonary consolidation associated with air-filled bronchi in children is presented. The consolidated area of the lung is usually hypoechoic, poorly defined, and wedge-shaped. The air-filled bronchi produce linear, high-amplitude branching echoes that converge toward the lung root. Posterior acoustic shadowing and reverberation artifacts are seen accompanying the proximal large bronchi. A comparative study is presented in which 30 pediatric patients with clinical and radiographic evidence of pneumonia were sonographically evaluated. Twenty-eight patients were successfully examined with sonography. The cases were divided into three groups: (1) consolidated lung without pleural effusion (19 patients); (2) consolidated lung with small pleural effusion (five patients); and (3) consolidated lung with partial compression atelectasis due to large pleural effusion (four patients).

Colonic obstruction in a child with von Recklinghausen's neurofibromatosis

A child is reported who developed partial colonic obstruction from an intussuscepting polypoid mass in the transverse colon. A 5 cm plexiform ganglioneurofibroma was found at laparotomy. Examination of the entire gastrointestinal tract revealed no other neurogenic tumors. Gastrointestinal involvement by neurofibromatosis in children is rare; however, children with von Recklinghausen's disease who complain of vague abdominal symptoms should be evaluated for gastrointestinal tumors.

Airway resistances of Blom-Singer and Panje Low Pressure tracheoesophageal puncture prostheses

Airway resistances were calculated for two newly commercialized tracheoesophageal (TE) puncture prostheses: the Panje Low Pressure Voice Button and the Blom-Singer Low Pressure device. The airway resistances of newly commercialized Panje Low Pressure devices could not be distinguished from those calculated for previously commercialized, Regular Pressure Voice Button devices. Airway resistances of Blom-Singer Low Pressure devices increased systematically as a function of flow rate. Findings are compared with existing data to provide readers with an opportunity to evaluate the relative efficiency of air shunting among contemporary TE puncture prostheses. Results are interpreted in relation to their implications for selecting surgical-prosthetic options for laryngectomized patients.