The promise of metabolic imaging in diffuse midline glioma.

Recent insights into histopathological and molecular subgroups of glioma have revolutionized the field of neuro-oncology by refining diagnostic categories. An emblematic example in pediatric neuro-oncology is the newly defined diffuse midline glioma (DMG), H3 K27-altered. DMG represents a rare tumor with a dismal prognosis. The diagnosis of DMG is largely based on clinical presentation and characteristic features on conventional magnetic resonance imaging (MRI), with biopsy limited by its delicate neuroanatomic location. Standard MRI remains limited in its ability to characterize tumor biology. Advanced MRI and positron emission tomography (PET) imaging offer additional value as they enable non-invasive evaluation of molecular and metabolic features of brain tumors. These techniques have been widely used for tumor detection, metabolic characterization and treatment response monitoring of brain tumors. However, their role in the realm of pediatric DMG is nascent. By summarizing DMG metabolic pathways in conjunction with their imaging surrogates, we aim to elucidate the untapped potential of such imaging techniques in this devastating disease.

Brachial plexopathy as a complication of COVID-19.

COVID-19 affects a wide spectrum of organ systems. We report a 52-year-old man with hypertension and newly diagnosed diabetes mellitus who presented with hypoxic respiratory failure due to COVID-19 and developed severe brachial plexopathy. He was not treated with prone positioning respiratory therapy. Associated with the flaccid, painfully numb left upper extremity was a livedoid, purpuric rash on his left hand and forearm consistent with COVID-19-induced microangiopathy. Neuroimaging and electrophysiological data were consistent with near diffuse left brachial plexitis with selective sparing of axillary, suprascapular and pectoral fascicles. Given his microangiopathic rash, elevated D-dimers and paucifascicular plexopathy, we postulate a patchy microvascular thrombotic plexopathy. Providers should be aware of this significant and potentially under-recognised neurologic complication of COVID-19.

Posterior Reversible Encephalopathy Syndrome.

PURPOSE OF REVIEW: This review provides an updated discussion on the clinical presentation, diagnosis and radiographic features, mechanisms, associations and epidemiology, treatment, and prognosis of posterior reversible encephalopathy syndrome (PRES). Headache is common in PRES, though headache associated with PRES was not identified as a separate entity in the 2018 International Classification of Headache Disorders. Here, we review the relevant literature and suggest criteria for consideration of its inclusion. RECENT FINDINGS: COVID-19 has been identified as a potential risk factor for PRES, with a prevalence of 1-4% in patients with SARS-CoV-2 infection undergoing neuroimaging, thus making a discussion of its identification and treatment particularly timely given the ongoing global pandemic at the time of this writing. PRES is a neuro-clinical syndrome with specific imaging findings. The clinical manifestations of PRES include headache, seizures, encephalopathy, visual disturbances, and focal neurologic deficits. Associations with PRES include renal failure, preeclampsia and eclampsia, autoimmune conditions, and immunosuppression. PRES is theorized to be a syndrome of disordered autoregulation and endothelial dysfunction resulting in preferential hyperperfusion of the posterior circulation. Treatment typically focuses on treating the underlying cause and removal of the offending agents.

Posterior reversible encephalopathy syndrome in patients with COVID-19.

OBJECTIVE: To report four patients with coronavirus disease 2019 (COVID-19) who developed posterior reversible encephalopathy syndrome (PRES). METHODS: Patient data was abstracted from medical records at Weill Cornell Medical Center. RESULTS: Four patients with SARS-CoV-2 infection and PRES were identified. The patients' ages ranged from 64 to 74 years, and two were women. All four patients were admitted to the hospital with acute respiratory distress syndrome requiring intensive care unit admission and mechanical ventilation. PRES was diagnosed after persistent confusion, lethargy, new focal neurological deficits, or seizures were noted, with evidence of seizures on electroencephalogram for two of the patients. Imaging confirmed the presence of cerebral vasogenic edema. All four patients had elevated blood pressure and renal injury in the days preceding PRES diagnosis, as well as evidence of systemic inflammation and systemic hypercoagulability. Symptoms of PRES improved with blood pressure control. CONCLUSIONS: Our four cases demonstrate the occurrence of PRES in critically-ill patients with COVID-19. PRES should be considered in the differential for acute neurological deficits and seizures in this setting.

Prospective evaluation of 18F-fluorodeoxyglucose positron emission tomography in patients receiving hepatic arterial and systemic chemotherapy for unresectable colorectal liver metastases.

BACKGROUND: The prognostic and predictive abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) coupled with conventional computed tomography (CT) have not been studied in patients with unresectable colorectal liver metastases (uCRLM) treated with combined hepatic arterial infusion (HAI) and systemic chemotherapy. OBJECTIVES: The ability of PET-CT metabolic response parameters to predict conversion to resectability and oncologic outcome in this setting was evaluated. METHODS: Thirty-eight patients undergoing serial PET-CT as part of a Phase II trial of HAI and systemic chemotherapy for uCRLM were included. Metabolic response was determined as the percentage change in standard uptake value (SUV) and total lesion glycolysis (TLG). Conversion to resection, overall survival (OS), progression-free survival (PFS) and recurrence-free survival were evaluated using standard statistics. RESULTS: Volumetric response sufficient to facilitate resection was seen in 53% of patients after a median of 5 months of therapy. Median follow-up was 38 months (range: 32-52 months). Median OS was not reached [95% confidence interval (CI) 32 months-unknown] and 3-year OS was 54% (range: 33-71%). Median PFS was 13 months (95% CI 6-21 months) and 3 year PFS was 10% (range: 3-20%). Neither baseline values nor the percentage change in any of the metabolic parameters evaluated correlated with conversion to resection, survival variables or hepatic recurrence on Cox regression analysis. CONCLUSIONS: Pre- and post-treatment PET-related metabolic parameters do not predict conversion to resection or oncologic outcome in patients with uCRLM treated with HAI and systemic chemotherapy. Metabolic parameters should not be used to monitor response or to determine prognosis in these patients.

RAS mutations affect pattern of metastatic spread and increase propensity for brain metastasis in colorectal cancer.

BACKGROUND: RAS and PIK3CA mutations in metastatic colorectal cancer (mCRC) have been associated with worse survival. We sought to evaluate the impact of RAS and PIK3CA mutations on cumulative incidence of metastasis to potentially curable sites of liver and lung and other sites such as bone and brain. METHODS: We performed a computerized search of the electronic medical record of our institution for mCRC cases genotyped for RAS or PIK3CA mutations from 2008 to 2012. Cases were reviewed for patient characteristics, survival, and site-specific metastasis. RESULTS: Among the 918 patients identified, 477 cases were RAS wild type, and 441 cases had a RAS mutation (394 at KRAS exon 2, 29 at KRAS exon 3 or 4, and 18 in NRAS). RAS mutation was significantly associated with shorter median overall survival (OS) and on multivariate analysis independently predicted worse OS (HR, 1.6; P < .01). RAS mutant mCRC exhibited a significantly higher cumulative incidence of lung, bone, and brain metastasis and on multivariate analysis was an independent predictor of involvement of these sites (HR, 1.5, 1.6, and 3.7, respectively). PIK3CA mutations occurred in 10% of the 786 cases genotyped, did not predict for worse survival, and did not exhibit a site-specific pattern of metastatic spread. CONCLUSIONS: The metastatic potential of CRC varies with the presence of RAS mutation. RAS mutation is associated with worse OS and increased incidence of lung, bone, and brain metastasis. An understanding of this site-specific pattern of spread may help to inform physicians' assessment of symptoms in patients with mCRC.

Phase II trial of hepatic artery infusional and systemic chemotherapy for patients with unresectable hepatic metastases from colorectal cancer: conversion to resection and long-term outcomes.

PURPOSE: Evaluate conversion rate of patients with unresectable colorectal-liver metastasis to complete resection with hepatic-arterial infusion plus systemic chemotherapy including bevacizumab (Bev). PATIENTS AND METHODS: Forty-nine patients with unresectable colorectal liver metastases (CRLM) were included in a single-institution phase II trial. Conversion to resection was the primary outcome. Secondary outcomes included overall survival (OS), progression-free survival, and response rates. Multivariate and landmark analyses were performed to evaluate survival differences between resected and nonresected patients. RESULTS: Median number of tumors was 14 and 65% were previously treated patients. A high biliary toxicity rate was found in the first 24 patients whose treatment included Bev. The remaining 25 patients were treated without Bev. Overall response rates were 76% (4 complete responses). Twenty-three patients (47%) achieved conversion to resection at a median of 6 months from treatment initiation. Median OS and progression-free survival for all patients were 38 (95% confidence interval: 28 to not reached) and 13 months (95% confidence interval: 7-16). Bev administration did not impact outcome. Conversion was the only factor associated with prolonged OS and progression-free survival in multivariate analysis. On landmark analysis, patients who had undergone resection had longer OS than those who did not undergo resection (3-year OS: 80% vs 26%). Currently, 10 of 49 (20%) patients have no evidence of disease (NED) at a median follow-up of 39 months (32-65 months). CONCLUSIONS: In patients with extensive unresectable CRLM, the majority of whom were previously treated, 47% were able to undergo complete resection after combined HAI and systemic therapy. Conversion to resection is associated with prolonged survival.

KRAS mutation influences recurrence patterns in patients undergoing hepatic resection of colorectal metastases.

BACKGROUND: The validity of the KRAS mutation as a predictor of recurrence-free survival (RFS) or overall survival (OS) is unclear. The current study investigated whether the presence of the KRAS mutation decreased RFS or OS in patients with colorectal cancer who underwent liver resection. METHODS: Patients with resected colorectal liver metastases who received adjuvant hepatic arterial infusion plus systemic therapy and for whom KRAS data was available were evaluated. Correlation between KRAS and clinical factors was done using the Fisher exact test. Kaplan-Meier methods were used to estimate the median RFS and OS. RESULTS: A total of 169 patients were evaluated, 118 of whom had KRAS wild-type (WT) and 51 had KRAS mutated (MUT) tumors. The 3-year RFS rate was 46% for patients with KRAS WT (95% confidence interval [95% CI], 35%-56%) and 30% (95% CI, 16%-44%) for patients with KRAS MUT (P =.005). The 3-year OS rate was 95% (95% CI, 87%-98%) and 81% (95% CI, 62%-95%), respectively, for patients with KRAS WT and KRAS MUT (P =.07). On multivariate analysis, KRAS remained a significant predictor of RFS (hazard ratio, 1.9). The 3-year cumulative recurrence rate by site of metastases was as follows: 2% versus 13.4% for bone (P≤.01), 2% versus 14.5% for brain (P =.05), 33.2% versus 58% for lung (P≤.01), and 30% versus 47% for liver (P =.10) in patients with KRAS WT versus KRAS MUT. CONCLUSIONS: In the current study, among patients with resected colorectal liver metastases who were treated with adjuvant hepatic arterial infusion plus systemic therapy, patients with KRAS MUT were found to have a significantly worse 3-year RFS (30%) compared with KRAS WT (46%) p=.005. The cumulative incidence of bone, brain, and lung metastases was significantly higher for patients with KRAS MUT compared with those with KRAS WT.

Angiographic identification of extrahepatic perfusion after hepatic arterial pump placement: implications for surgical prevention.

BACKGROUND: Hepatic arterial infusion (HAI) chemotherapy is an effective treatment for patients with liver malignancy. Extrahepatic perfusion (EHP) after HAI pump placement requires correction prior to starting chemotherapy. The aim of this study was to define the origin of arterial branches causing EHP in order to determine if alterations in surgical technique during pump placement might prevent EHP. METHODS: A prospectively maintained, single-centre HAI database was reviewed for all patients (2008-2011) with EHP. The origin of arterial branches causing EHP was classified anatomically and patient outcomes were analysed. RESULTS: Of the 327 patients with pumps implanted, 24 evidenced EHP. The arterial branch responsible for EHP perfused the duodenum, pancreas and/or stomach. The branch responsible for EHP arose from the proper hepatic artery (PHA), 1(st) , 2(nd) , or 3(rd) order hepatic artery branches in 7, 10, 5 and 2 patients, respectively. The majority of branches beyond the PHA causing EHP (13/17) originated from the right hepatic artery. In 18 patients, aberrant branches were successfully treated with embolization. CONCLUSION: These findings provide the anatomic basis for prevention of up to one-third of the cases of EHP intra-operatively, decreasing the number of patients who will require additional procedures for correction of EHP post-operatively.

Treating primary liver cancer with hepatic arterial infusion of floxuridine and dexamethasone: does the addition of systemic bevacizumab improve results?

OBJECTIVES: This study investigated the efficacy and safety of adding systemic (IV) bevacizumab (Bev) to hepatic arterial infusion (HAI) with floxuridine (FUDR)/dexamethasone (Dex) in unresectable primary liver cancer. METHODS: Patients with unresectable intrahepatic cholangiocarcinoma (ICC) or hepatocellular carcinoma (HCC) were treated with HAI FUDR/Dex plus IV Bev. Results were compared to a recent study of HAI without Bev in a similar patient population. RESULTS: Twenty-two patients (18 ICC, 4 HCC) were treated with HAI FUDR/Dex plus Bev; 7 (31.8%) had partial response and 15 (68.2%) had stable disease. Median survival was 31.1 months (CI 14.14-33.59), progression-free survival (PFS) 8.45 months (CI 5.53-11.05), and hepatic PFS 11.3 months (CI 7.93-15.69). In the previous trial with HAI alone (no Bev), the response was 50%; median survival, PFS, and hepatic PFS were 29.5, 7.3, and 10.1 months. In the present trial, bilirubin elevation (>2 mg/dl) was seen in 24% of patients and biliary stents were placed in 13.6%, versus 5.8 and 0%, respectively, in the HAI trial without Bev. Due to increased biliary toxicity, the trial was prematurely terminated. CONCLUSION: Adding Bev to HAI FUDR/Dex appeared to increase biliary toxicity without clear improvement in outcome (median PFS 8.45 vs. 7.3 months, and median survival 31.1 vs. 29.5 months, for HAI + Bev vs. HAI alone groups, respectively).

Randomized phase II trial of adjuvant hepatic arterial infusion and systemic chemotherapy with or without bevacizumab in patients with resected hepatic metastases from colorectal cancer.

PURPOSE: Add systemic bevacizumab (Bev) to adjuvant hepatic arterial infusion (HAI) plus systemic therapy after liver resection to increase recurrence-free survival (RFS). PATIENTS AND METHODS: Patients were randomly assigned to HAI plus systemic therapy with or without Bev. If 1-year RFS of ≥ 80% was obtained in Bev arm, then the regimen would be studied further. HAI with fluorodeoxyuridine plus dexamethasone was given on days 1 to 14 of a 5-week cycle. Systemic therapy and Bev 5 mg/kg was delivered on days 15 and 29: oxaliplatin 85 mg/m², leucovorin 400 mg/m², and fluorouracil 2,000 mg/m² infusion for 2 days (if patients received prior oxaliplatin, then irinotecan 150 mg/m² was used). RFS and survival were estimated by using the Kaplan-Meier method and compared by using the log-rank test. RESULTS: The two arms had similar characteristics: synchronous disease (66% v 63%), more than one metastasis (84% v 74%), and clinical risk score ≥ 3 (50% v 46%) for no Bev versus Bev arms, respectively. With a median follow-up of 30 months, 4-year survival was 85% and 81% (P = .5), and 4-year RFS was 46% versus 37%; 1-year RFS was 83% and 71% (P = .4) for no Bev versus Bev arms. Bilirubin > 3 mg/dL was seen in zero of 38 versus five of 35 patients (P = .02) and biliary stents were placed in zero versus four patients (P = .05) in no Bev versus Bev arms. CONCLUSION: The addition of Bev to adjuvant HAI plus systemic therapy after liver resection did not seem to increase RFS or survival but appeared to increase biliary toxicity. Four-year survival was 85% and 81% for no Bev and Bev arms, respectively.