Interactions between ploidy and resource availability shape clonal interference at initiation and recurrence of glioblastoma

Glioblastoma (GBM) is the most aggressive form of primary brain tumor. Complete surgical resection of GBM is almost impossible due to the infiltrative nature of the cancer. While no evidence for recent selection events have been found after diagnosis, the selective forces that govern gliomagenesis are strong, shaping the tumor's cell composition during the initial progression to malignancy with late consequences for invasiveness and therapy response. We present a mathematical model that simulates the growth and invasion of a glioma, given its ploidy level and the nature of its brain tissue micro-environment (TME), and use it to make inferences about GBM initiation and response to standard-of-care treatment. We approximate the spatial distribution of resource access in the TME through integration of in-silico modelling, multi-omics data and image analysis of primary and recurrent GBM. In the pre-malignant setting, our in-silico results suggest that low ploidy cancer cells are more resistant to starvation-induced cell death. In the malignant setting, between first and second surgery, simulated tumors with different ploidy compositions progressed at different rates. Whether higher ploidy predicted fast recurrence, however, depended on the TME. Historical data supports this dependence on TME resources, as shown by a significant correlation between the median glucose uptake rates in human tissues and the median ploidy of cancer types that arise in the respective tissues (Spearman r = -0.70; P = 0.026). Taken together our findings suggest that availability of metabolic substrates in the TME drives different cell fate decisions for cancer cells with different ploidy and shapes GBM disease initiation and relapse characteristics.

Phase II multi-institutional clinical trial result of concurrent cetuximab and nivolumab in recurrent and/or metastatic head and neck squamous cell carcinoma

PURPOSE

A phase II multi-institutional clinical trial was conducted to determine overall survival (OS) in patients with recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) treated with a combination of cetuximab and nivolumab.

EXPERIMENTAL DESIGN

Patients with R/M HNSCC were treated with cetuximab 500 mg/m2 IV Day (D) -14 as a lead-in followed by cetuximab 500 mg/m2 IV and nivolumab 240 mg IV on D1 and D15 of each 28-D cycle. Expression of p16 and programmed cell death-ligand 1 (PD-L1) in archived tumors were determined. Tumor-tissue-modified human papillomavirus (TTMV) DNA was quantified in plasma.

RESULTS

Ninety-five patients were enrolled, and 88 patients were evaluable for OS with a median follow-up of 15.9 months. Median OS in the 45 patients who had prior therapy for R/M HNSCC (Cohort A) was 11.4 months, with a 1-year OS 50% (90% CI, 0.43-0.57). Median OS in the 43 patients who had no prior therapy (Cohort B) was 20.2 months, with a 1-year OS 66% (90% CI, 0.59-0.71). In the combined cohorts, the p16-negative immunostaining was associated with higher response rate (RR, p=0.02) but did not impact survival while higher PD-L1 combined positive score was associated with higher RR (p=0.03) and longer OS (log-rank p=0.04). In the p16-positive patients, median (log-rank p=0.05).

CONCLUSION

The combination of cetuximab and nivolumab is effective in patients with both previously treated and untreated R/M HNSCC and warrants further evaluation.

NTRK3 gene fusion in an adult ganglioglioma: illustrative case

BACKGROUND

Gangliogliomas are well-differentiated, slow-growing glioneuronal neoplasms frequently reported to harbor upregulating alterations in the mitogen-activated protein kinase pathway, particularly serine–threonine protein kinase B-RAF alterations. Fusions involving neurotrophin tyrosine receptor kinase (NTRK) genes have rarely been reported in ganglioglioma. Similarly, echinoderm microtubule-associated protein-like (EML) 4 gene fusion has been described in lung cancer, but none has been reported in ganglioglioma.

OBSERVATIONS

This report discusses the care of a 72-year-old man presenting with medication-refractory, left-sided focal seizures who was found to have a nongadolinium-enhancing, T2-hyperintense, right frontoparietal lesion. The patient received resection, and histological analysis found a World Health Organization grade I ganglioglioma, with genetic analysis demonstrating an EML4-NTRK3 gene fusion protein.

LESSONS

To our knowledge, this is the first report of an NTRK3 fusion, EML4-NTRK3, in an adult ganglioglioma, which is otherwise mostly associated with BRAF alterations and activation of the mitogen-activated protein kinase signaling pathway. Further studies are needed to elucidate the function of the resultant fusion protein and determine whether it may serve as a future therapeutic target.

Preoperative Evaluation of Craniopagus Twins: Anatomy, Imaging Techniques, and Surgical Management

Craniopagus twins are a rare congenital malformation in which twins are conjoined at the head. Although there is high prenatal and postnatal mortality for craniopagus twins, successful separation has become more common due to advances in neuroimaging, neuroanesthesia, and neurosurgical techniques. Joined brain tissue, shared arteries and veins, and defects in the skull and dura make surgery technically challenging, and neuroimaging plays an important role in preoperative planning. Drawing on our experience from consultation for multiple successful separations of craniopagus twins, we discuss what radiologists need to know about the anatomy, classification, imaging techniques, and surgical management of craniopagus twins.

Occult Nodal Disease and Occult Extranodal Extension in Patients With Oropharyngeal Squamous Cell Carcinoma Undergoing Primary Transoral Robotic Surgery With Neck Dissection

Importance

The historically reported rates of subclinical cervical nodal metastases in oropharyngeal squamous cell carcinoma (OPSCC) predate the emergence of human papillomavirus as the predominant causative agent. The rate of occult nodal disease with changing etiology of OPSCC is not known, and it is challenging to anticipate which patients will be upstaged postoperatively and will require adjuvant therapy.

Objective

To assess the rate of nodal upstaging and occult extranodal extension (ENE) in a multi-institutional population of patients with pathologic (p)T1-2 OPSCC treated by transoral robotic surgery and neck dissection.

Design, Setting and Participants

This retrospective, multicenter cohort study of 92 participants at 2 US institutions (Albert Einstein College of Medicine, Bronx, New York [n = 38], and Icahn School of Medicine at Mount Sinai, New York, New York [n = 39]) and 1 Canadian institution (Princess Margaret Hospital, Toronto [n = 15]) examined the rate of postoperative pathologic upstaging for 92 patients with pT1-2 OPSCC undergoing transoral robotic surgery with neck dissection from August 2007 to December 2016. A neuroradiologist at each site blinded to final pathologic diagnosis reviewed preoperative imaging; these findings were compared with operative pathology and applied for tumor staging using the eighth edition of the American Joint Committee on Cancer Cancer Staging Manual. The statistical analysis was performed on December 18, 2018.

Main Outcomes and Measures

Occult pathologic nodal disease and change in nodal category postoperatively.

Results

Of 92 patients who met the inclusion criteria, 76 (83%) were male, and they had a mean (SD) age at surgery of 59.5 (10.5) years; 70 patients (84%) with available p16 status were positive. Five of 18 patients (28%) who had no evidence of nodal disease on imaging had occult pathologic nodal disease. Seven of 32 patients (22%) presenting with no nodal disease or with a single metastatic node on imaging received pathologic upstaging because of multiple positive nodes, indicating implementation of additional adjuvant treatment not anticipated after a priori imaging. Changes included 12 patients (13%) who had pathologic nodal upstaging and 12 (13%) with pathologic nodal downstaging in the eighth edition of staging. In the cohort, 24 patients (27%) had pathologic ENE, and 5 of 39 patients (13%) had occult ENE in the absence of radiographic evidence.

Conclusions and Relevance

Predicting pathologic staging preoperatively for patients with OPSCC undergoing transoral robotic surgery and neck dissection remains a challenge. Although nodal size, tumor size, and location do not help predict ENE, the presence of nodes on imaging and nodal category may help predict ENE. Our findings suggest a small proportion of patients might benefit from further adjuvant therapies not predicted by preoperative imaging based on occult nodal upstaging and ENE.

Glioblastoma multiforme presenting with an open ring pattern of enhancement on MR imaging

Background:

Intracerebral ring enhancing lesions can be the presentation of a variety of pathologies, including neoplasia, inflammation, and autoimmune demyelination. Use of a precise diagnostic algorithm is imperative in correctly treating these lesions and minimizing potential adverse treatment effects.

Case Description:

A 55-year-old patient presented to the hospital with complaints of a post-concussive syndrome and a non-focal neurologic exam. Imaging revealed a lesion with an open ring enhancement pattern, minimal surrounding vasogenic edema, and minimal mass effect. Given the minimal mass effect, small size of the lesion, and nonfocal neurological exam, we elected to pursue a comprehensive noninvasive neurologic workup because our differential ranged from inflammatory/infectious to neoplasm. Over the next 8 weeks, the patient's condition worsened, and repeat imaging showed marked enlargement of the lesion with a now closed ring pattern of enhancement with satellite lesions and a magnetic resonance (MR) spectroscopy and perfusion signature suggestive of neoplasm. The patient was taken to surgery for biopsy and debulking of the lesion. Surgical neuropathology examination revealed glioblastoma multiforme.

Conclusion:

The unique open ring enhancement pattern of this lesion on initial imaging is highly specific for a demyelinating process, however, high-grade glial neoplasms can also present with complex and irregular ring enhancement including an open ring sign. Therefore, other imaging modalities should be used, and close follow-up is warranted when the open ring sign is encountered.

Incidental primary mediastinal choriocarcinoma diagnosed by endobronchial ultrasound-guided fine needle aspiration in a patient presenting with transient ischemic attack and stroke

We describe a case of a 41-year old male patient with no significant prior medical history who presents with symptoms of Transient Ischemic Attack and stroke. Magnetic Resonance Imaging (MRI) of the brain identified areas of ischemia in the left side, and angiography showed occlusion of the left Medial Cerebral Artery (MCA). Cardiac Transthoracic Echocardiogram (TTE) for stroke evaluation incidentally noted a mediastinal abnormality leading to cancer work-up. Computer Tomography (CT) and ¹⁸ F-fluorodeoxyglucose (FDG) PET-CT scan of the chest incidentally revealed an avid 6 cm paraesophagial/subcarinal mass. Further diagnostic work-up with endoscopic and endobronchial ultra sound (EBUS)-guided fine needle aspiration (FNA) of the mass yielded a cytology diagnosis of Germ Cell Tumor (GCT), with choriocarcinoma component. Additionally, high plasma levels of β-human chorionic gonadotrophin (β-HCG) were detected with no evidence of testicular tumor. This exceedingly rare presentation for a primary mediastinal choriocarcinoma underscores the importance of complete investigation of young patients presenting with neurological symptoms compatible with ischemic events. Diagn. Cytopathol. 2017;45:738-743. © 2017 Wiley Periodicals, Inc.

Central venous occlusion mimics carotid cavernous fistula: a case report and review of the literature

A patient presented with signs and symptoms of a left carotid cavernous fistula (CCF). Computed tomography angiography confirmed filling of the cavernous sinus in the arterial phase. Cerebral digital subtraction angiography demonstrated no evidence of CCF. The workup, diagnosis, and treatment of this patient are discussed, and the literature is reviewed.

Assessment of an introductory cervicocerebral catheter angiography learning program: a pilot study

BACKGROUND AND PURPOSE

There is no standardized curriculum currently available at most institutions for establishing procedural competency in trainees performing cervicocerebral angiography. The purpose of this study was to evaluate a simple learning program to supplement the teaching of basic cervicocerebral angiography.

MATERIALS AND METHODS

An 11-session interactive curriculum was implemented covering anatomic, clinical, and radiographic topics for the novice cervicocerebral angiographer. The target learner was the neuroradiology fellow. Data were gathered regarding fellow comfort level on topics relating to cervicocerebral angiography by using a 5-point Likert scale. Improvement in scores on knowledge-based questions after completion of the curriculum was calculated (McNemar test). Trainee-perceived utility of the program was also recorded by using a 5-point Likert scale. Focus sessions were held at the completion of the curriculum to gather feedback regarding the strengths and weaknesses of the program from participants.

RESULTS

Ten subjects were enrolled in this pilot study for 3 years. Topics where participants reported a poor initial comfort level (4 or higher) included selection of injection rates and volumes and reformation of reverse-curve catheters. Trainees demonstrated a statistically significant change in the distribution of scores of 29.3% (49.4%-78.7% correct response rate, P < .0001). The average perceived utility was 1.5 (1 = most useful, 5 = least useful).

CONCLUSIONS

This simple learning program was a useful adjunct to the training of fellows in diagnostic cervicocerebral angiography, resulting in quantitative improvements in knowledge.

Endovascular transvenous embolization of sinus pericranii. Case report

Sinus pericranii (SP) is an abnormal communication between the intra- and extracranial venous drainage pathways. Treatment of this condition has mainly been recommended for reasons of cosmesis and prevention of hemorrhage. The authors report a novel endovascular transvenous route for definitive treatment of SP.

Computed tomography–guided lumbar drain placement

The authors describe a technique for lumbar drain placement using CT guidance. Midline or paramidline interlaminar approaches to the thecal sac can be used. The major advantage to CT guidance is direct visualization of the needle tip in relation to the thecal sac. This technical approach is a safe and rapid alternative to fluoroscopic guidance for the placement of lumbar drains in patients in whom standard lumbar drain placement techniques have failed.