The evaluation of the effects of steroid treatment on the tumor and peritumoral edema by DWI and MR spectroscopy in brain tumors

Brain-Tumor Interface-Based MRI Radiomics Models to Determine EGFR Mutation, Response to EGFR-TKI and T790M Resistance Mutation in Non-Small Cell Lung Carcinoma Brain Metastasis

BACKGROUND

Preoperative assessment of epidermal growth factor receptor (EGFR) status, response to EGFR-tyrosine kinase inhibitors (TKI) and development of T790M mutation in non-small cell lung carcinoma (NSCLC) patients with brain metastases (BM) is important for clinical decision-making, while previous studies were only based on the whole BM.

PURPOSE

To investigate values of brain-to-tumor interface (BTI) for determining the EGFR mutation, response to EGFR-TKI and T790M mutation.

STUDY TYPE

Retrospective.

POPULATION

Two hundred thirty patients from Hospital 1 (primary cohort) and 80 patients from Hospital 2 (external validation cohort) with BM and histological diagnosis of primary NSCLC, and with known EGFR status (biopsy) and T790M mutation status (gene sequencing).

FIELD STRENGTH/SEQUENCE

Contrast-enhanced T1-weighted (T1CE) and T2-weighted (T2W) fast spin echo sequences at 3.0T MRI.

ASSESSMENT

Treatment response to EGFR-TKI therapy was determined by the Response Evaluation Criteria in Solid Tumors. Radiomics features were extracted from the 4 mm thickness BTI and selected by least shrinkage and selection operator regression. The selected BTI features and volume of peritumoral edema (VPE) were combined to construct models using logistic regression.

STATISTICAL TESTS

The performance of each radiomics model was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS

A total of 7, 3, and 3 features were strongly associated with the EGFR mutation status, response to EGFR-TKI and T790M mutation status, respectively. The developed models combining BTI features and VPE can improve the performance than those based on BTI features alone, generating AUCs of 0.814, 0.730, and 0.774 for determining the EGFR mutation, response to EGFR-TKI and T790M mutation, respectively, in the external validation cohort.

DATA CONCLUSION

BTI features and VPE were associated with the EGFR mutation status, response to EGFR-TKI and T790M mutation status in NSCLC patients with BM.

EVIDENCE LEVEL

3 Technical Efficacy: Stage 2.

Conventional and Advanced Magnetic Resonance Imaging Assessment of Non-Enhancing Peritumoral Area in Brain Tumor

The non-enhancing peritumoral area (NEPA) is defined as the hyperintense region in T2-weighted and fluid-attenuated inversion recovery (FLAIR) images surrounding a brain tumor. The NEPA corresponds to different pathological processes, including vasogenic edema and infiltrative edema. The analysis of the NEPA with conventional and advanced magnetic resonance imaging (MRI) was proposed in the differential diagnosis of solid brain tumors, showing higher accuracy than MRI evaluation of the enhancing part of the tumor. In particular, MRI assessment of the NEPA was demonstrated to be a promising tool for distinguishing high-grade gliomas from primary lymphoma and brain metastases. Additionally, the MRI characteristics of the NEPA were found to correlate with prognosis and treatment response. The purpose of this narrative review was to describe MRI features of the NEPA obtained with conventional and advanced MRI techniques to better understand their potential in identifying the different characteristics of high-grade gliomas, primary lymphoma and brain metastases and in predicting clinical outcome and response to surgery and chemo-irradiation. Diffusion and perfusion techniques, such as diffusion tensor imaging (DTI), diffusional kurtosis imaging (DKI), dynamic susceptibility contrast-enhanced (DSC) perfusion imaging, dynamic contrast-enhanced (DCE) perfusion imaging, arterial spin labeling (ASL), spectroscopy and amide proton transfer (APT), were the advanced MRI procedures we reviewed.

Advantages and drawbacks of dexamethasone in glioblastoma multiforme

The most widespread, malignant, and deadliest type of glial tumor is glioblastoma multiforme (GBM). Despite radiation, chemotherapy, and radical surgery, the median survival of afflicted individuals is about 12 months. Unfortunately, existing therapeutic interventions are abysmal. Dexamethasone (Dex), a synthetic glucocorticoid, has been used for many years to treat brain edema and inflammation caused by GBM. Several investigations have recently shown that Dex also exerts antitumoral effects against GBM. On the other hand, more recent disputed findings have questioned the long-held dogma of Dex treatment for GBM. Unfortunately, steroids are associated with various undesirable side effects, including severe immunosuppression and metabolic changes like hyperglycemia, which may impair the survival of GBM patients. Current ideas and concerns about Dex's effects on GBM cerebral edema, cell proliferation, migration, and its clinical outcomes were investigated in this study.

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.

The Effects of Administrated Dexamethasone on Neurologic Assessment in Neuro-oncology Scale in Patients with Intracranial Tumors

BACKGROUND: In intracranial tumors, glucocorticoids are the main therapy to treat peritumoral edema. Neurologic Assessment in Neuro-Oncology (NANO) score is an instrument that can assess neurological function objectively and practically in patients with intracranial tumors. AIM: This study aims to determine the effect of dexamethasone administration on the NANO score of intracranial tumor patients. METHODS: This study was a pre-experimental study with a pre and post-test design at the H. Adam Malik General Hospital in Medan from March to September 2020. The study population was intracranial tumor patients. The research subject were 37 subjects taken consecutively. Treated with dexamethasone injection, then examined the NANO score before and after receiving dexamethasone injection on days 1, 2, and 3. Statistical analysis with Friedman test. RESULTS: Based on the demographic characteristics of the research subjects, the mean age was 53.29 ± 8.5 years. Most of the research subjects were male (54.1%) while female (45.9%). Most types of intracranial tumors were secondary tumors (59.5%) while primary tumors (40.5%). The significant effect of dexamethasone on NANO score in patients with intracranial tumors (p < 0.001). CONCLUSION: There is an effect of dexamethasone on the NANO score of patients with intracranial tumors.

[Epidemiological, clinical, therapeutic and evolutionary features of patients with glioblastoma: series of cases managed in the Department of Hematology-Oncology at the Mohammed VI University Hospital Center in Marrakech in 2016 and 2017]

Glioblastoma is the most common primary malignant brain tumour. Despite advances in diagnostic and therapeutic treatments, it is still associated with poor outcome The purpose of this study of cases is to describe the epidemiological, clinical, therapeutic and evolutionary features of patients with glioblastoma admitted to the Department of Hematology-Oncology (DHO) in Marrakech in 2016 and 2017. We conducted a literature review of epidemiological, clinical, radiological, anatomopathological, therapeutic and evolutionary data from 40 patients. Glioblastoma accounted for 47.6% of treated intracranial tumours. The average age of patients was 52.4±12.3 years. Functional impotence and signs of intracranial hypertension were the main symptoms. Tumours mainly occurred in the parietal region (44%) and were large (57.5%). Aphasia was related to tumour size (p=0.042). Nine cases had glioblastomas-IDH1-wild and one case had glioblastoma-IDH1-mutant. On admission, patients had poor performance-status. This was due to a prolonged time between surgery and DHO admission (p= 0.034). Patients with sensory impairments were older (62.5±3 years) than those without sensory impairments (51.2±12 years) (p=0,045). In-patient women received chemoradiotherapy (1.5±1 month) earlier than men (2.3±1.2 months) (p=0.03). Survival was 13.6±5.3 months; it was unrelated to the time to surgery (p=0.076), the time to DHO (p=0.058), and the time to chemoradiotherapy (p=0.073). The epidemiological, clinical, radiological and evolutionary features of our sample were comparable to literature data. The molecular profiling was not systematically realized. Despite prolonged treatment times, no link to survival was detected.

Surgical Management of Giant Intracranial Meningiomas

Objective

Giant intracranial meningiomas are a challenge for neurosurgeons because of their size and location in the cranium. Difficult tumor dissection and encasement of important neurovascular structures make them a horrible nightmare. The aims of this study are to present our giant intracranial meningioma series and to compare our experience using advanced surgical technology with the current literature.

Materials and Methods

The data of patients with the diagnosis of giant intracranial meningioma between 2014 and 2020 who underwent surgical treatment were retrospectively reviewed. The demographic, radiological, and surgical characteristics of patients were documented. The size and location of tumors as well as surgical technique were analyzed in detail.

Results

A total of 61 patients with intracranial meningioma underwent surgical treatment over a 7-year period, and 10 (16.4%) tumors were larger than 5 cm in diameter, which were classified as giant meningioma. Seven patients were male and 3 were female, with a mean age of 64.9 years. Four tumors were located at the skull base. Histological diagnosis was meningioma World Health Organization grade I in 7 patients and grade II in 3 patients. Simpson grade 1 resection was achieved in 6 patients and grade 2 resection in 4 patients. No mortality was observed.

Conclusion

Careful surgical planning should be made for giant intracranial meningiomas. Their location, adjacent neurovascular structures, and vascular supply affect the resection level of these giant tumors. Simpson grade 1 resection is seldom possible for skull base meningiomas.

Untangling the diffusion signal using the phasor transform

Separating the decay signal from diffusion-weighted scans into two or more components can be challenging. The phasor technique is well established in the field of optical microscopy for visualization and separation of fluorescent dyes with different lifetimes. The use of the phasor technique for separation of diffusion-weighted decay signals was recently proposed. In this study, we investigate the added value of this technique for fitting decay models and visualization of decay rates. Phasor visualization was performed in five glioblastoma patients. Using simulations, the influence of incorrect diffusivity values and of the number of b-values on fitting a three-component model with fixed diffusivities (dubbed "unmixing") was investigated for both a phasor-based fit and a linear least squares (LLS) fit. Phasor-based intravoxel incoherent motion (IVIM) fitting was compared with nonlinear least squares (NLLS) and segmented fitting (SF) methods in terms of accuracy and precision. The distributions of the parameter estimates of simulated data were compared with those obtained in a healthy volunteer. In the phasor visualizations of two glioblastoma patients, a cluster of points was observed that was not seen in healthy volunteers. The identified cluster roughly corresponded to the enhanced edge region of the tumor of two glioblastoma patients visible on fluid-attenuated inversion recovery (FLAIR) images. For fitting decay models the usefulness of the phasor transform is less pronounced, but the additional knowledge gained from the geometrical configuration of phasor space can aid fitting routines. This has led to slightly improved fitting results for the IVIM model: phasor-based fitting yielded parameter maps with higher precision than the NLLS and SF methods for parameters f and D (interquartile range [IQR] for f: NLLS 27, SF 12, phasor 5.7%; IQR for D: NLLS 0.28, SF 0.18, phasor 0.10 μm² /s). For unmixing, LLS fitting slightly but consistently outperformed phasor-based fitting in all of the tested scenarios.

Bevacizumab for the treatment of non-small cell lung cancer patients with synchronous brain metastases

Bevacizumab is FDA-approved in the treatment of primary brain tumors, but its efficacy in patients with brain metastases could be better-studied. This study examines a population of non-small cell lung cancer (NSCLC) patients with synchronous brain metastases to identify predictors of the decision to use bevacizumab and survival following bevacizumab treatment. Primary cancer registry data were used to determine which NSCLC patients diagnosed in the years 2010 through 2012 had synchronous brain metastases at the time of diagnosis, and Medicare claims used to identify a population of patients treated with bevacizumab. Record of bevacizumab treatment was found for 81 and 666 patients with and without brain metastases, respectively. After adjusting for clinical and demographic characteristics, bevacizumab was associated with 0.88 times the hazard of mortality in the elderly NSCLC population (95% CI: 0.81–0.96, p: 0.003) and a corresponding hazard ratio of 0.75 in the population of elderly NSCLC patients with synchronous brain metastases (95% CI: 0.59–0.96, p: 0.020). Bevacizumab may benefit NSCLC patients with synchronous brain metastases more than it does patients without intracranial disease, possibly as a result of its multiple potential mechanisms of action simultaneously inhibiting angiogenesis and minimizing vasogenic edema.

Efficiency of Dexamethasone for Treatment of Vasogenic Edema in Brain Metastasis Patients: A Radiographic Approach

Background and Purpose: To date, imaging studies quantifying the amount of vasogenic edema reduction (VE) in patients with brain metastases (BM) treated with glucocorticoids (GC) have included a very limited number of patients and showed ambiguous results. Here, we aim to determine the radiological effect of GC on VE in BM patients in a large cohort with multiple primary tumor entities in a cross-sectional approach.

Materials and Methods: This monocentric retrospective study includes 299 patients first-ever diagnosed with 2,759 intra-axial BM on the respective MRI. 126/299 patients received GC prior to MRI due to mass effect of edema on cranial CT scan and clinical symptoms (GC-pos) and 173 patients did not (GC-neg). GC dose was documented in 85/126 patients. All BM and their respective VE were semi-automatically segmented on post-contrast T1-weighted images.

Results: VE volumes were higher in GC-pos compared to GC-neg (p = 0.009) and did not correlate with GC dose. Multivariate linear regression analysis with interaction terms on the assumption that BM volume and BM number influence the probability of GC administration shows that large and higher numbers of BM under GC treatment generate less VE than without (p < 0.001 and p = 0.038, respectively). The primary tumor type and total BM volume did not influence VE volume.

Conclusion: Use of GC is especially effective for treatment of VE formation in patients with larger and multiple BM regardless of primary tumor type and dosage. However, based on the present data a direct causative relationship between GC and VE cannot be proven.

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.

Dexamethasone in Glioblastoma Multiforme Therapy: Mechanisms and Controversies

Glioblastoma multiforme (GBM) is the most common and malignant of the glial tumors. The world-wide estimates of new cases and deaths annually are remarkable, making GBM a crucial public health issue. Despite the combination of radical surgery, radio and chemotherapy prognosis is extremely poor (median survival is approximately 1 year). Thus, current therapeutic interventions are highly unsatisfactory. For many years, GBM-induced brain oedema and inflammation have been widely treated with dexamethasone (DEX), a synthetic glucocorticoid (GC). A number of studies have reported that DEX also inhibits GBM cell proliferation and migration. Nevertheless, recent controversial results provided by different laboratories have challenged the widely accepted dogma concerning DEX therapy for GBM. Here, we have reviewed the main clinical features and genetic and epigenetic abnormalities underlying GBM. Finally, we analyzed current notions and concerns related to DEX effects on cerebral oedema, cancer cell proliferation and migration and clinical outcome.

Progesterone Is More Effective Than Dexamethasone in Prolonging Overall Survival and Preserving Neurologic Function in Experimental Animals with Orthotopic Glioblastoma Allografts

OBJECTIVE

Dexamethasone (DEXA) has been widely used in the management of peritumoral brain edema. DEXA, however, has many systemic side effects and can interact negatively with glioma therapy. Progesterone (PROG), however, is a well-tolerated and readily accessible anti-inflammatory and antiedema agent, with potent neuroprotective properties. We investigated whether PROG could serve as a viable alternative to DEXA in the management of peritumoral brain edema.

METHODS

We used an orthotopic C6 glioblastoma model with male Sprague-Dawley rats. Tumor grafts were allowed to grow for 14 days before drug treatment with DEXA 1 mg/kg, PROG 10 mg/kg, or PROG 20 mg/kg for 5 consecutive days. The overall animal survival and neurologic function were evaluated. Mechanistic studies on blood-brain barrier permeability and angiogenic responses were performed on the ex vivo tumor grafts.

RESULTS

We found that all drug treatments prolonged overall survival to different extents. PROG 10 mg led to significantly longer survival and better preservation of neurologic function and body weight. The blood-brain barrier permeability was better preserved with PROG 10 mg than with DEXA, possibly through downregulation of matrix metalloproteinase-9 and aquaporin-4 expression. Antiangiogenic responses were also observed in the PROG group.

CONCLUSIONS

The present proof-of-concept pilot study has provided novel information on the use of PROG as a corticosteroid-sparing agent in brain tumor management. Further translational and clinical studies are warranted.