Medical decompressive therapy for primary and metastatic intracranial tumours

Effect of mannitol on platelet function during elective craniotomy in adult patients with brain tumor

BACKGROUND

Mannitol is used in the treatment of raised intracranial pressure (ICP). The aim of this study was to investigate whether mannitol (MAN) leads to a relevant deterioration in platelet function in routine neurosurgical procedures.

METHODS

Thirty-eight patients undergoing elective craniotomy due to a brain tumor with elevated ICP were included. After induction of anesthesia a blood sample was taken (T1). The patients then received 1 g∙kg-1 MAN within 30 minutes. The second blood sample (T2) was obtained 60 minutes after T1. Blood samples were examined by means of aggregometry (Multiplate®; Roche, Basel, Switzertland) and PFA-100® tests (Siemens Healthineers, Erlangen, Germany).

RESULTS

No patient had clinical signs of increased bleeding. We could not find any deterioration in the aggregometry using Multiplate® (Roche), neither in the adenosine diphosphate (ADP), the arachidonic acid (ASPI), or the thrombin receptor activating protein (TRAP) test. PFA-100® (Siemens Healthineers) closing times (cT) showed a significant prolongation between T1 and T2: collagen/adenosine diphosphate (COL/ADP) test 79 s [70/99] and 91 s [81/109]; P=0.002); collagen/epinephrine (COL/EPI) test 109 s [92/129] and 122 s [94/159]; P=0.0004). A subgroup analysis showed that the patients who received isotonic balanced infusions only, had no prolongation of cT, whereas the patients who received additionally gelatin solution had a significant prolongation. COL/ADP: 78 s [70/98] and 91 s [82/133]; P=0.0004). COL/EPI: test 111 s [92/128] and 127 s [103/146]; P=0.0026). Except for individual outliers, the measured values were in the normal range.

CONCLUSIONS

In this study, we found no clinically relevant deterioration of platelet function in neurosurgical patients with increased ICP after administration of MAN. Changes that occurred were all within normal ranges.

Acetazolamide versus placebo for cerebral oedema requiring dexamethasone in recurrent and/or progressive high-grade glioma: phase II randomised placebo-controlled double-blind study

OBJECTIVES

Symptoms of raised intracranial pressure (ICP) in recurrent high-grade glioma (HGG) generally require corticosteroid treatment, often causing toxicity with variable effects on ICP symptoms. Acetazolamide reduces ICP when used in other clinical non-cancer settings. The aim of the study was to explore whether the addition of oral acetazolamide enables safe dexamethasone dose reduction in management of raised ICP in recurrent HGG.

METHODS

Participants had recurrent HGG with any of dexamethasone recommencement, dose increase or dependency; prior/current bevacizumab was an exclusion. Eligible participants were randomised 1:1 to acetazolamide or placebo for 8 weeks. Standardised protocols were used for dexamethasone dosing, with planned dose decrease from day 5 once ICP symptoms were stable. The primary endpoint was a composite of dexamethasone dose reduction and stable Karnofsky Performance Status Secondary endpoints included toxicity and feasibility.

RESULTS

Thirty participants (15 per group) were enrolled (mean age 58 years) from seven Australian sites. The mean baseline dexamethasone dose was 6.2 mg. Mean duration on study treatment was 38 days (placebo group) and 31 days (acetazolamide group) with nine participants (30%) completing all study treatments (six placebo, three acetazolamide). Study withdrawal was due to adverse events (n=6; one placebo, five acetazolamide) and disease progression (n=6 (three per arm)). Four participants (13%) (two per arm) were stable responders. Ten participants experienced a total of 13 serious adverse events (acetazolamide arm: five participants (33%), six events, two related).

CONCLUSIONS

The study closed early due to poor accrual and increasing availability of bevacizumab. The addition of acetazolamide did not facilitate dexamethasone reduction.

TRIAL REGISTRATION NUMBER

ACTRN12615001072505.

Do animal models of brain tumors replicate human peritumoral edema? a systematic literature search

INTRODUCTION

Brain tumors cause morbidity and mortality in part through peritumoral brain edema. The current main treatment for peritumoral brain edema are corticosteroids. Due to the increased recognition of their side-effect profile, there is growing interest in finding alternatives to steroids but there is little formal study of animal models of peritumoral brain edema. This study aims to summarize the available literature.

METHODS

A systematic search was undertaken of 5 literature databases (Medline, Embase, CINAHL, PubMed and the Cochrane Library). The generic strategy was to search for various terms associated with "brain tumors", "brain edema" and "animal models".

RESULTS

We identified 603 reports, of which 112 were identified as relevant for full text analysis that studied 114 peritumoral brain edema animal models. We found significant heterogeneity in the species and strain of tumor-bearing animals, tumor implantation method and edema assessment. Most models did not produce appreciable brain edema and did not test for observable manifestations thereof.

CONCLUSION

No animal model currently exists that enable the investigation of novel candidates for the treatment of peritumoral brain edema. With current interest in alternative treatments for peritumoral brain edema, there is an unmet need for clinically relevant animal models.

Tackling brain metastases from lung cancer during the COVID-19 pandemic

Given the enormous strain the COVID-19 pandemic has put on healthcare worldwide, appropriate allocation of resources according to priority is of immense importance. As brain metastases are a common presentation in lung cancer, during the pandemic, it potentially can pose a major management challenge to clinicians. In this article, we outline a pragmatic approach that oncologists should consider while managing these patients. The overarching principle is to deliver best, evidence-based treatment without compromising patient care while ensuring the safety of healthcare workers.

Practice variation in perioperative steroid dosing for brain tumor patients: an international survey

OBJECTIVE

Steroids are commonly used against peritumoral edema and increased intracranial pressure in brain tumor patients. Despite the widespread use of steroids, relatively little evidence is available about their optimal perioperative dosing scheme. This study aims to increase insight into practice variation of perioperative steroid dosing and tapering schedules used in the neurosurgical community.

METHODS

An electronic survey consisting of 27 questions regarding steroid dosing, tapering schedules, and adverse events was conducted among neurosurgeons between December 6^th, 2019 and June 1^st, 2020. The survey was distributed through the European Association of Neurosurgical Societies and social media platforms. Collected data were assessed for quantitative and qualitative analysis.

RESULTS

The survey obtained 175 responses from 55 countries across six continents, including 30 from low- or middle-income countries; 152 (87%) respondents completed all questions. In total, 130 respondents (80%) indicated prescribing perioperative steroids. Reported doses ranged from 2 to 64 mg/day in schedules ranging from one to four times daily. The most prescribed steroid was dexamethasone in a dose of 16 mg/day (n = 49; 31%), followed by 12 mg/day (n = 31; 20%) and 8 mg/day (n = 18; 12%). No significant association was found between prescribed dose and physician and institutional characteristics.

CONCLUSION

Steroids are commonly prescribed perioperatively in brain tumor patients. However, there is a great practice variation in dosing and schedules among neurosurgeons. Future investigation in a prospective and preferably randomized manner is needed to identify an optimal dosing scheme and implement (inter)national guidelines for steroid use.

Practice review: Evidence-based quality use of corticosteroids in the palliative care of patients with advanced cancer

BACKGROUND

It would be unusual for a patient with advanced cancer not to be prescribed corticosteroids at some stage of their disease course for a variety of specific and non-specific indications.

AIM

The aim of this practice review was to provide a pragmatic overview of the evidence supporting current practice and to identify areas in which further research is indicated.

DESIGN

A 'state-of-the-art' review approach was used to examine the evidence supporting the use of corticosteroids for the management of cancer-related complications and in symptom control, in the context of known risks and harms to inform quality use of this medicine. We developed 'Do', 'Do not', and 'Don't know' recommendations based on current literature and identified areas for future investigation and research.

DATA SOURCES

We searched MEDLINE, EMBASE and the Cochrane library from inception to 14th October 2020. Our initial search limited to reviews, reviews of reviews, randomised controlled trials (RCTs) and controlled trials was supplemented by supporting literature as appropriate.

RESULTS

Evidence to support common practice in the use of corticosteroids is lacking for most indications. This is in the context of strong evidence for the potential for significant toxicity and poor quality use of medicine.

CONCLUSION

Guidelines recommending the widespread use of corticosteroids should acknowledge the poor evidence base supporting much current dogma. Quality research is essential not only to define the role of corticosteroids in this context but to ensure good prescribing practice.

[Perioperative dexamethasone]

Dexamethasone is a synthetic steroid that has been used for many years in the clinical routine due to its anti-inflammatory, anti-allergic and immunosuppressive properties. Furthermore, dexamethasone has been used for a long time for prophylaxis and treatment of chemotherapy-induced nausea and vomiting. In the meantime dexamethasone has been approved as standard for the prophylaxis and treatment of postoperative nausea and vomiting (PONV). This review article outlines the indications and side effects of the perioperative administration of dexamethasone.

Provider views on perioperative steroid use for patients with newly diagnosed pediatric brain tumors

PURPOSE

Cerebral edema from brain tumors can cause neurological impairment. Steroids treat edema but with possible adverse effects. We surveyed providers regarding steroid use in newly diagnosed patients with brain tumors to determine if practices are standard or markedly variable.

METHODS

An anonymous voluntary online survey was sent to members of neuro-oncology consortiums. Four clinical scenarios were provided and questions regarding initiation of steroids, type, dose, formulation, and duration were asked. Demographic information was collected.

RESULTS

369 providers received the survey, 76 responded (20.6% response rate). The proportion of providers who would start steroids significantly differed among scenarios (scenario 1 vs 2, p < 0.001; 2 vs 3, p < 0.001; 1 vs 3, p < 0.001). 75 (98.7%) providers would start steroids for vasogenic edema (scenario 1) and 55 (72.4%) for obstructive hydrocephalus (scenario 2). 16 (21.1%) would start steroids for vasogenic edema but not obstructive hydrocephalus. The odds of choosing to start steroids in patients with obstructive hydrocephalus were 7.59 times more (95% CI: 2.29, 25.13) if providers felt symptoms would improve within 24 h. All would use dexamethasone. A significant difference was seen between the proportion of providers who would give a loading dose if vasogenic edema with neurological deficits were noted versus vasogenic edema alone (57.9% vs 43.4%; p = 0.002).

CONCLUSIONS

These results suggest that providers recommend dexamethasone for patients with vasogenic edema and obstructive hydrocephalus. Variability remains with dosing schedule. Further studies are needed to identify the most appropriate use of steroids for newly diagnosed CNS tumor patients with the goal to create steroid management guidelines.

Bevacizumab as a treatment option for radiation necrosis after cranial radiation therapy: a retrospective monocentric analysis

BACKGROUND AND PURPOSE

Radiation necrosis is a possible adverse event after cranial radiation therapy and can cause severe symptoms, such as an increased intracranial pressure or neurological deterioration. The vascular endothelial growth factor (VEGF) inhibitor bevacizumab (BEV) has been shown to be a feasible therapeutic option for symptomatic radiation necrosis, either when traditional antiedematous steroid treatment fails, or as an alternative to steroid treatment. However, to the best of our knowledge, only one randomized study with a rather small cohort exists to prove a beneficial effect in this setting. Therefore, further real-life data are needed. This retrospective monocentric case study evaluates patients who received BEV due to radiation necrosis, with a specific focus on the respective clinical course.

METHODS

Using the internal database for pharmaceutical products, all patients who received BEV in our department were identified. Only patients who received BEV as symptomatic treatment for radiation necrosis were included. Patient characteristics, symptoms before, during, and after treatment, and the use of dexamethasone were evaluated using medical reports and systematic internal documentation. The symptoms were graded using CTCAE version 5.0 for general neurological symptoms. Symptoms were graded directly before each cycle and after the treatment (approximately 6 weeks). Additionally, the daily steroid dose was collected at these timepoints. Patients who either improved in symptoms, received less dexamethasone after treatment, or both were considered to have a benefit from the treatment.

RESULTS

Twenty-one patients who received BEV due to radiation necrosis were identified. For 10 patients (47.6%) symptoms improved and 11 patients (52.4%) remained clinically stable during the treatment. In 14 patients (66.7%) the dexamethasone dose could be reduced during therapy, 5 patients (23.8%) received the same dose of dexamethasone before and after the treatment, and 2 patients (9.5%) received a higher dose at the end of the treatment. According to this analysis, overall, 19 patients (90.5%) benefited from the treatment with BEV. No severe adverse effects were reported.

CONCLUSION

BEV might be an effective and safe therapeutic option for patients with radiation necrosis as a complication after cranial radiation therapy. Patients seem to benefit from this treatment by improving symptomatically or through reduction of dexamethasone.

Influence of Dexamethasone on O-(2-[18F]-Fluoroethyl)-L-Tyrosine Uptake in the Human Brain and Quantification of Tumor Uptake

PURPOSE

O-(2-[¹⁸F]fluoroethyl)-L-tyrosine ([¹⁸F]FET) is an established positron emission tomography (PET) tracer for brain tumor imaging. This study explores the influence of dexamethasone therapy on [¹⁸F]FET uptake in the normal brain and its influence on the maximum and mean tumor-to-brain ratio (TBR).

PROCEDURES

[¹⁸F]FET PET scans of 160 brain tumor patients were evaluated (80 dexamethasone treated, 80 untreated; each group with 40 men/40 women). The standardized uptake value of [¹⁸F]FET uptake in the normal brain (SUV_brain) in the different groups was compared. Nine patients were examined repeatedly with and without dexamethasone therapy.

RESULTS

SUV_brain of [¹⁸F]FET uptake was significantly higher in dexamethasone-treated patients than in untreated patients (SUV_brain 1.33 ± 0.1 versus 1.06 ± 0.16 in male and 1.45 ± 0.25 versus 1.31 ± 0.28 in female patients). Similar results were observed in patients with serial PET scans. Furthermore, compared to men, a significantly higher SUV_brain was found in women, both with and without dexamethasone treatment. There were no significant differences between the different groups for TBR_max and TBR_mean, which could have been masked by the high standard deviation. In a patient with a stable brain metastasis investigated twice with and without dexamethasone, the TBR_max and the biological tumor volume (BTV) decreased considerably after dexamethasone due to an increased SUV_brain.

CONCLUSION

Dexamethasone treatment appears to increase the [¹⁸F]FET uptake in the normal brain. An effect on TBR_max, TBR_mean, and BTV cannot be excluded which should be considered especially for treatment monitoring and the estimation of BTV using [¹⁸F]FET PET.

Evidence-based dexamethasone dosing in malignant brain tumors: what do we really know?

Purpose

The present study aims to conduct a systematic review of literature reporting on the dose and dosing schedule of dexamethasone (DXM) in relation to clinical outcomes in malignant brain tumor patients, with particular attention to evidence-based practice.

Methods

A systematic search was performed in PubMed, Embase, Web of Science, Cochrane, Academic Search Premier, and PsycINFO to identify studies that reported edema volume reduction, symptomatic relief, adverse events and survival in relation to dexamethasone dose in glioma or brain metastasis (BM) patients.

Results

After screening 1812 studies, fifteen articles were included for qualitative review. Most studies reported a dose of 16 mg, mostly in a schedule of 4 mg four times a day. Due to heterogeneity of studies, it was not possible to perform quantitative meta-analysis. For BMs, best available evidence suggests that higher doses of DXM may give more adverse events, but may not necessarily result in better clinical condition. Some studies suggest that higher DXM doses are associated with shorter survival in the palliative setting. For glioma, DXM may lead to symptomatic improvement, yet no studies directly compare different doses. Results regarding edema reduction and survival in glioma patients are conflicting.

Conclusions

Evidence on the safety and efficacy of different DXM doses in malignant brain tumor patients is scarce and conflicting. Best available evidence suggests that low DXM doses may be noninferior to higher doses in certain circumstances, but more comparative research in this area is direly needed, especially in light of the increasing importance of immunotherapy for brain tumors.

Electronic supplementary material

The online version of this article (10.1007/s11060-019-03238-4) contains supplementary material, which is available to authorized users.

Influence of blood-brain barrier permeability on O-(2-18F-fluoroethyl)-L-tyrosine uptake in rat gliomas

PURPOSE

O-(2-¹⁸F-fluoroethyl)-L-tyrosine (¹⁸F-FET) is an established tracer for the diagnosis of brain tumors with PET. This study investigates the influence of blood-brain barrier (BBB) permeability on ¹⁸F-FET uptake in two rat glioma models and one human xenograft model.

METHODS

F98 glioma, 9L gliosarcoma or human U87 glioblastoma cells were implanted into the striatum of 56 Fischer or RNU rats. Thereafter, animals were divided into a control group and a group receiving injections of the glucocorticoid dexamethasone (Dex). After 12-13 days of tumor growth animals received injection of Evans blue dye (EBD) to visualize BBB disturbance and underwent ¹⁸F-FET PET followed by autoradiography. Time activity curves, standardized uptake values (SUV) and Tumor-to-brain ratios (TBR) of ¹⁸F-FET uptake [18-61 min post injection (p.i.)] were evaluated using a volume-of-Interest (VOI) analysis. BBB disturbance was quantitatively evaluated by EBD fluorescence. The membrane gaps of blood vessel endothelial tight junctions were measured using electron microscopy to visualize ultrastructural BBB alterations in one untreated and one Dex treated F98 glioma. Data were analyzed by two-way ANOVAs.

RESULTS

In Dex treated animals EBD extravasation was significantly reduced in 9L (P < 0.001) and U87 (P = 0.008) models and showed a trend in F98 models (P = 0.053). In contrast, no significant differences of ¹⁸F-FET uptake were observed between Dex treated animals and control group except a decrease of the TBR in the 9L tumor model in PET (P < 0.01). Ultrastructural evaluation of tumor blood vessel endothelia revealed significant reduction of the cleft diameter between endothelial cells after Dex treatment in F98 model (P = 0.010).

CONCLUSION

Despite a considerable reduction of BBB permeability in rat gliomas after Dex treatment, no relevant changes of ¹⁸F-FET uptake were noted in this experimental study. Thus, ¹⁸F-FET uptake in gliomas appears to be widely independent of the permeability of the BBB.

Validating self-report and proxy reports of the Dexamethasone Symptom Questionnaire -Chronic for the evaluation of longer-term corticosteroid toxicity

PURPOSE

In brain tumours, brain metastases or advanced cancer; treatment with corticosteroids, side effects can add to symptoms. These are best assessed by patients, complementing clinical assessment. We assessed the feasibility and validity of the Dexamethasone Symptom Questionnaire-Chronic (DSQ-Chronic), patient and caregiver versions.

METHODS

A longitudinal cohort study was conducted, collecting clinician-rated toxicity, performance status, dexamethasone dose and DSQ-Chronic (patient and caregiver versions) at baseline, then 2, 4 and 8 weeks later. Patients had a primary malignant brain tumour, brain metastases, or advanced cancer; Karnofsky Performance Status ≥40 and predicted survival ≥8 weeks. Analysis included questionnaire completion rates, frequency and severity of dexamethasone-attributable side effects, agreement between patient and caregiver ratings, comparison with clinician-rated toxicity and correlation with performance status.

RESULTS

Sixty-six patients were recruited (mean age 60 years), with their caregivers. Completion of questionnaires was over 90% for the dyad at baseline but dropped over time, with caregiver completion rates higher at all timepoints. Agreement between patients and proxies was fair to moderate, and while proxies systematically overestimated symptom severity on DSQ-chronic total scores, the bias was less than 10 points. Patient and clinician agreement was higher for more objective symptoms.

CONCLUSION

The DSQ-Chronic is feasible when the patient is relatively well. As capacity to complete the DSQ-Chronic diminishes, caregivers can be proxy-raters. Clinicians capture corticosteroid toxicities, which may not be obvious to the patient. The DSQ-Chronic, patient and caregiver versions, are useful tools to be used with clinician assessment.

A systematic review of the literature on the effects of dexamethasone on the brain from in vivo human-based studies: implications for physiological brain imaging of patients with intracranial tumors

BACKGROUND

Among glucocorticoids, dexamethasone is most widely used for treatment of cerebral edema because of its long biological half-life and its low mineralocorticoid activity (sodium retaining).

OBJECTIVE

A systematic review of the literature on the effects of dexamethasone on the brain from in vivo studies in humans.

METHODS

A MEDLINE database search (via the PubMed interface) and an EMBASE database search (via the Dialog interface) of the past 35 years was performed. Every article relating to human use reported in English was included. In addition, references of all eligible articles were searched to identify other possible sources.

RESULTS

Twenty-four articles matched the eligibility criteria. There were disparate methodologies and conflicting results, although they tended to indicate a decrease in blood-tumor barrier permeability, decreased tumoral perfusion, decreased tumoral diffusivity, and the possibility of decreased perfusion in contralateral normal-appearing brain tissue.

CONCLUSION

Treatment with dexamethasone may alter imaging parameters from cerebral perfusion studies used in the management of brain tumors. In adequately powered studies, it may be possible to assess the longer term effects of dexamethasone on normal brain tissue to help optimize use with longer term survivors that are emerging as improvements in glioma treatment are made.

Cerebral edema, altered mental status, seizures, acute stroke, leptomeningeal metastases, and paraneoplastic syndrome

Neurologic symptoms commonly occur in oncology patients, and in some cases they may be the presenting symptom of malignancy. Cancer-related neurologic syndromes are rarely pathognomonic and must be differentiated from other benign or serious conditions. This article reviews common neuro-oncologic syndromes that may lead to urgent evaluation in the emergency department, including cerebral edema, altered mental status, seizures, acute stroke, leptomeningeal metastases, and paraneoplastic neurologic syndromes.

Investigation of neuroprotective effect of dexamethasone by using nitric oxide and leukocyte levels in experimental head trauma

The objective of the present study was to determine the levels of nitric oxide (NO) and white blood cells (WBCs), which are assumed to play a role in secondary cerebral damage by increasing to pathological levels during cranial trauma, and to investigate the neuroprotective effect of dexamethasone on NO and WBC levels in experimental cranial trauma. For this purpose, adult Sprague-Dawley male rats were used. Blood NO and WBC levels were investigated in one group of non-trauma rats (control group, n = 10) after 6 h; in a group of rats with experimental post-cranial trauma (trauma group, n = 10) after 6 and 24 h; and in a third group of rats with experimental cranial trauma, intraperitoneally injected with 10 mg/kg dexamethasone after 1 and 12 h (trauma + dexamethasone group, n = 10), WBC and NO levels were measured after 6 and 24 h. Determination of NO levels was carried out by assaying serum nitrite and nitrate levels. The increases in post-trauma serum NO (nitrite and nitrate) and WBC levels were statistically significant for the trauma and trauma + dexamethasone groups compared to controls. There was no significant difference between serum NO and WBC levels in rats in the trauma + dexamethasone and those in the trauma group. The study demonstrated no significant inhibition of NO and WBC levels by dexamethasone, a drug used for its anti-edema and anti-inflammatory effects and its influence on membrane stabilization and in avoiding oscillation stress. In the present study, dexamethasone was found to be ineffective in decreasing NO and WBC levels to avoid secondary cerebral damage after cranial trauma.

Treating gliomas with glucocorticoids: from bedside to bench

Glucocorticoids are used in the treatment of gliomas to decrease tumour-associated oedema and to reduce the risk of acute encephalopathy associated with radiotherapy. However, the mechanisms by which glucocorticoids work are still largely unknown. In this paper, we survey the experimental and clinical evidence for the effects of glucocorticoids on tumour cell proliferation, apoptosis and sensitivity to chemotherapy, angiogenesis and vascular permeability. We then review current guidelines on the choice of molecule, dose and duration of glucocorticoid treatment for gliomas.