Faculty Bibliography

BACKGROUND:While immune checkpoint inhibitors (ICI) induce potent responses against several systemic malignancies, clinical efficacy against high-grade glioma has been limited by immunosuppression, low mutational burden and limited lymphocyte infiltration into tumors. Laser interstitial thermal therapy (LITT) induces coagulative necrosis and disrupts the peritumoral blood-brain barrier (BBB), creating a potentially antigenic milieu. We hypothesized that neoadjuvant and adjuvant ICI would synergize with LITT to potentiate antitumor immune responses and enhance survival. METHODS:This retrospective study is an exploratory case series that includes 9 adult patients with recurrent IDH wild-type glioblastoma (GBM, n = 6), IDH mutant high-grade astrocytoma (n = 2) and H3K27M mutant diffuse midline glioma (n = 1). All patients received neoadjuvant anti-PD1 ICI prior to LITT and most received adjuvant ICI (8/9). Disease burden was followed through radiographic volume segmentation of gadolinium-enhancing disease. Patients were followed for progression-free (PFS) and overall survival (OS). RESULTS:). There were no perioperative complications. All patients showed an initial increase in gadolinium-enhancing volume after LITT. Seven of 9 (78 %) patients demonstrated subsequent regression in total gadolinium-enhancing volume. Three non-contiguous satellite lesions naïve to laser ablation exhibited complete or near-complete regression in 2 patients. Median PFS was 5.90 months (range 1.00-41.23), and median OS was 9.97 months (range 1.20-41.23). CONCLUSIONS:Combination therapy with neoadjuvant and adjuvant pembrolizumab and LITT is feasible and safe in recurrent high-grade glioma. Responses may be more robust in certain molecular subtypes of glioma. Further studies are needed to investigate this potential synergy.

PURPOSE/OBJECTIVE:Histopathological grading of IDH-mutant astrocytomas demonstrates limited prognostic accuracy. However, DNA methylation subclassification has demonstrated improved prognostication beyond histological grading. This study aimed to investigate the associations between imaging features, tumor volumetric data, and DNA methylation grade in IDH-mutant astrocytomas. METHODS:We analyzed imaging features and volumetric data for 72 patients diagnosed with IDH-mutant astrocytomas, who underwent preoperative MRI and DNA methylation profiling. VASARI features and multicompartmental volumetrics were evaluated. Logistic regression was used to identify imaging predictors of methylation subclass, WHO histologic grade, copy number variation (CNV), and CDKN2A/B homozygous deletion. Univariable and multivariable Cox proportional hazard models were also developed to assess these variables' influence on overall survival and progression-free survival. RESULTS:Patients were classified into 27 methylation high-grade (A_IDH_HG) and 45 methylation low-grade (A_IDH_LG) tumors. Tumor volumes and proportions varied by methylation grade, CNV status, and WHO histologic grade, but not by CDKN2A/B status. Imaging features distinguished methylation subclasses with 75% accuracy (AUC = 0.77). Methylation high-grade subclass was associated with imaging features such as midline crossing, ependymal extension, and poorly defined enhancing margins. Predictive performance for WHO histologic grade, CNV status, and CDKN2A/B deletion was moderate (AUC = 0.67, 0.69, and 0.65, respectively). Methylation grade, CDKN2A/B status, VASARI features, and proportions of edema and non-contrast enhancing tumor were significantly associated with survival. CONCLUSION/CONCLUSIONS:MRI-derived imaging features facilitate noninvasive prediction of DNA methylation subclass in IDH-mutant astrocytomas.

Craniopharyngiomas are histologically benign central nervous system tumors derived from embryonic epithelial cells of Rathke's pouch. The disease demonstrates a bimodal age distribution, occurring most often in patients 5-14 and 50-74 years of age. Common comorbidities include hypopituitarism, hypothalamic obesity, sleep apnea, visual impairment and neurocognitive disturbances. There are several key differences in the presentation, tumor characteristics and clinical outcomes between age groups. Childhood craniopharyngiomas are mostly adamantinomatous and often present as larger tumors with worse functional outcomes such as rates of obesity and neurological deficits. Adults experience similar but slightly adjusted rates of comorbidity with both the adamantinomatous and papillary subtypes. This review presents a case-based discussion of adult craniopharyngiomas, focusing on recent literature regarding their presentation, pathology and pathogenesis, diagnosis, treatment and long-term sequelae.

Listeriosis has more than a 50% mortality when the central nervous system is involved, necessitating rapid diagnosis and treatment. We present four patients with brain abscesses in the setting of diagnosed neurolisteriosis, all of which demonstrated an odd presentation of multiple small, contiguous tubular lesions with rim enhancement on magnetic resonance imaging. Our review of published cases of neurolisteriosis suggests that this may be a useful pattern to identify neurolisteriosis abscesses, allowing earlier detection and therapy.

A 74-year-old man with chronic obstructive pulmonary disease, glaucoma, and Stage IIIB squamous cell lung cancer experienced several minutes of flashing lights in his right visual hemifield, followed by onset of a right visual field defect. On examination, the patient had a right homonymous hemianopsia that was most dense inferiorly by confrontation testing. Emergent CT scan of the head revealed a 2.5 × 3 cm hypodensity in the left occipital lobe, which was interpreted as an acute stroke. Continuous EEG monitoring captured left posterior quadrant seizures that were temporally correlated to the positive visual phenomena. Subsequent MRI of the brain with and without contrast revealed a conglomerate of centrally necrotic and peripherally enhancing mass lesions. On biopsy, a thick purulent material was drained and Gram stain of the sample revealed gram-positive beaded rods, which speciated to Nocardia farcinica. The patient was treated with a six-week course of intravenous meropenem and a one-year course of oral trimethroprim-sulfamethoxazole. On follow-up, the patient experienced resolution of the right visual field deficit.

BACKGROUND AND PURPOSE:Most multinodular and vacuolating neuronal tumors (MVNTs) are diagnosed and followed radiologically without any change across time. There are no surveillance guidelines or quantitative volumetric assessments of these tumors. We evaluated MVNT volumes during long follow-up periods using segmentation tools with the aim of quantitative assessment. MATERIALS AND METHODS:All patients with MVNTs in a brain MR imaging report in our system were reviewed. Patients with only 1 brain MR imaging or in whom MVNT was not clearly the most likely diagnosis were excluded. All MVNTs were manually segmented. For all follow-up examinations, absolute and percentage volume change from immediately prior and initial examinations were calculated. RESULTS:= .67), respectively. CONCLUSIONS:MVNT segmentation across follow-up brain MR imaging examinations did not demonstrate significant volume differences, suggesting that these tumors do not enlarge with time. Hence, frequent surveillance imaging of newly diagnosed MVNTs may not be necessary.

Meaningful contributions to neurointerventional practice may be possible by considering the dynamic aspects of angiography in addition to fixed morphologic information. The functional approach to venous anatomy requires integration of the traditional static anatomic features of the system-deep, superficial, posterior fossa, medullary veins, venous sinuses, and outflow routes into an overall appreciation of how a classic model of drainage is altered, embryologically, or pathologically, depending on patterns of flow-visualization made possible by angiography. In this review, emphasis is placed on balance between alternative venous networks and their redundancy, and the problems which arise when these systems are lacking. The role of veins in major neurovascular diseases, such as dural arteriovenous fistulae, arteriovenous malformations, pulsatile tinnitus, and intracranial hypertension, is highlighted, and deficiencies in knowledge emphasized.

Spine trauma represents a common indication for imaging in the emergency department. Multidetector CT imaging, with its advantage of multiplanar reconstructions and fast image acquisition, is the technique of choice in the initial assessment of a patient with poly-trauma. While many simple spinal fractures are adequately evaluated on 2D multiplanar reconstruction images, more complex, potentially displaced fracture patterns can be more fully highlighted on 3D reconstructions. Compared with conventional volume-rendering techniques, cinematic rendering uses a complex illumination model to create a more pho-torealistic representation of the fracture patterns, images that are certain to excite both trainees and clinicians. This review demonstrates the educational value and clinical utility of 3D cinematic rendering images in understanding complex spinal column injuries. Learning Objective: To demonstrate the methodology, clinical applicability, and educational utility behind 3D photorealistic cinematic rendering images of spine injuries, with emphasis on the "tension bands" biomechanical concept.