Low-grade astrocytoma: surgical outcomes in eloquent versus non-eloquent brain areas

Effect of high-field iMRI guided resection in cerebral glioma surgery: A randomized clinical trial

BACKGROUND

Extent of resection (EOR) in glioma contributes to longer survival. The purpose of NCT01479686 was to prove whether intraoperative magnetic resonance imaging (iMRI) increases EOR in glioma surgery and benefit survival.

METHODS

Patients were randomized (1:1) to receive the iMRI (n = 161) or the conventional neuronavigation (n = 160). The primary endpoint was gross total resection (GTR); secondary outcomes reported were progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

188 high-grade gliomas (HGGs) and 133 low-grade gliomas (LGGs) were enrolled. GTR was 83.85% in the iMRI group vs. 50.00% in the control group (P < 0.0001). In 321 patients, the median PFS (mPFS) was 65.12 months in the iMRI group and 61.01 months in the control group (P = 0.0202). For HGGs, mPFS was improved in the iMRI group (19.32 vs. 13.34 months, P = 0.0015), and a trend of superior OS compared with control was observed (29.73 vs. 25.33 months, P = 0.1233). In the predefined eloquent area HGG subgroup, mPFS, and mOS were 20.47 months and 33.58 months in the iMRI vs. 12.21 months and 21.16 months in the control group (P = 0.0098; P = 0.0375, respectively). From the exploratory analyses of HGGs, residual tumor volume (TV) < 1.0 cm3 decreased the risk of survival (mPFS: 18.99 vs. 9.43 months, P = 0.0055; mOS: 29.77 vs. 18.10 months, P = 0.0042). LGGs with preoperative (pre-OP) TV > 43.1 cm3 and postoperative (post-OP) TV > 4.6 cm3 showed worse OS (P= 0.0117) CONCLUSIONS: It showed that iMRI significantly increased EOR and indicated survival benefits for HGGs, particularly eloquent HGGs. Residual TV in either HGGs or LGGs is a prognostic factor for survival.

Preoperative assessment of eloquence in neurosurgery: a systematic review

BACKGROUND AND OBJECTIVES

Tumor location and eloquence are two crucial preoperative factors when deciding on the optimal treatment choice in glioma management. Consensus is currently lacking regarding the preoperative assessment and definition of eloquent areas. This systematic review aims to evaluate the existing definitions and assessment methods of eloquent areas that are used in current clinical practice.

METHODS

A computer-aided search of Embase, Medline (OvidSP), and Google Scholar was performed to identify relevant studies. This review includes articles describing preoperative definitions of eloquence in the study's Methods section. These definitions were compared and categorized by anatomical structure. Additionally, various techniques to preoperatively assess tumor eloquence were extracted, along with their benefits, drawbacks and ease of use.

RESULTS

This review covers 98 articles including 12,714 participants. Evaluation of these studies indicated considerable variability in defining eloquence. Categorization of these definitions yielded a list of 32 brain regions that were considered eloquent. The most commonly used methods to preoperatively determine tumor eloquence were anatomical classification systems and structural MRI, followed by DTI-FT, functional MRI and nTMS.

CONCLUSIONS

There were major differences in the definitions and assessment methods of eloquence, and none of them proved to be satisfactory to express eloquence as an objective, quantifiable, preoperative factor to use in glioma decision making. Therefore, we propose the development of a novel, objective, reliable, preoperative classification system to assess eloquence. This should in the future aid neurosurgeons in their preoperative decision making to facilitate personalized treatment paradigms and to improve surgical outcomes.

Clinical application of 3.0 T intraoperative magnetic resonance combined with multimodal neuronavigation in resection of cerebral eloquent area glioma

Glioma is the most common tumor among central nervous system tumors; surgical intervention presents difficulties. This is especially the case for gliomas in so-called "eloquent areas," as surgical resection threatens vital structures adjacent to the tumor. Intraoperative magnetic resonance imaging (iMRI) combined with multimodal neuronavigation may prove beneficial during surgery. This study explored the applicability of 3.0 T high field iMRI combined with multimodal neuronavigation in the resection of gliomas in eloquent brain areas.We reviewed 40 patients with a glioma located in the eloquent brains areas who underwent treatment in the Neurosurgery Department of Peking University International Hospital between December 2015 and August 2017. The experimental group included 20 patients treated using iMRI assistance technology (iMRI group). The remaining 20 patients underwent treatment by conventional neuronavigation (non-iMRI group). Tumor resection degree, preoperative and postoperative ability of daily living scale (Barthel index), infection rate, and operative time were compared between the 2 groups.No difference in infection rate was observed between the 2 groups. However, compared with the non-iMRI group, the iMRI group had a higher resection rate (96.55 ± 4.03% vs 87.70 ± 10.98%, P = .002), postoperative Barthel index (90.75 ± 12.90 vs 9.25 ± 16.41, P = .018), as well as a longer operation time (355.85 ± 61.40 vs 302.45 ± 64.09, P = .011).The use of iMRI technology can achieve a relatively higher resection rate among cases of gliomas in eloquent brain areas, with less incidence of postoperative neurological deficits. Although the operative time using iMRI was longer than that taken to perform conventional navigation surgery, the surgical infection rate in these 2 procedures showed no significant difference.

Quantitative proteomic analysis shows differentially expressed HSPB1 in glioblastoma as a discriminating short from long survival factor and NOVA1 as a differentiation factor between low-grade astrocytoma and oligodendroglioma

Background

Gliomas account for more than 60 % of all primary central nervous system neoplasms. Low-grade gliomas display a tendency to progress to more malignant phenotypes and the most frequent and malignant gliomas are glioblastomas (GBM). Another type of glioma, oligodendroglioma originates from oligodendrocytes and glial precursor cells and represents 2–5 % of gliomas. The discrimination between these two types of glioma is actually controversial, thus, a molecular distinction is necessary for better diagnosis.

Methods

iTRAQ-based quantitative proteomic analysis was performed on non-neoplastic brain tissue, on astrocytoma grade II, glioblastoma with short and long survival and oligodendrogliomas.

Results

We found that expression of nucleophosmin (NPM1), glucose regulated protein 78 kDa (GRP78), nucleolin (NCL) and heat shock protein 90 kDa (HSP90B1) were increased, Raf kinase inhibitor protein (RKIP/PEBP1) was decreased in glioblastoma and they were associated with a network related to tumor progression. Expression level of heat shock protein 27 (HSPB1/HSP27) discriminated glioblastoma presenting short (6 ± 4 months, n = 4) and long survival (43 ± 15 months, n = 4) (p = 0.00045). Expression level of RNA binding protein nova 1 (NOVA1) differentiated low-grade oligodendroglioma and astrocytoma grade II (p = 0.0082). Validation were done by Western blot, qRT-PCR and immunohistochemistry in a larger casuistry.

Conclusion

Taken together, our quantitative proteomic analysis detected the molecular triad, NPM1, GRP78 and RKIP participating together with NCL and HSP27/HSPB1 in a network related to tumor progression. Additionally, two new important targets were uncovered: NOVA1 useful for diagnostic refinement differentiating astrocytoma from oligodendroglioma, and HSPB1/HSP27, as a predictive factor of poor prognosis for GBM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1473-9) contains supplementary material, which is available to authorized users.

Prognostic Factors in Lobar World Health Organization Grade II Astrocytomas

BACKGROUND

World Health Organization grade II astrocytomas (AII) are the commonest low-grade glioma subset, but their prognostic factors are subject to debate. This institutional study aimed to identify prognostic factors in lobar AII.

METHODS

Retrospective review of newly diagnosed, lobar AII between 2006 and 2012. Patient demographics, imaging, and treatment data were obtained. Isocitrate dehydrogenase-1 (IDH1) status was assessed via immunohistochemistry. Multivariate analysis was performed with Cox regression to identify prognostic factors for overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 92 adult patients were identified with a median age of 42 years (range 20-73 years) and median follow-up period of 45 months (range, 7-98 months). Seizures were the commonest mode of presentation (75%). IDH1 immunopositivity was seen in 46 of 83 patients (55%). Radiology diagnosis agreed with histology in 76% of cases, and 28% of tumors had documented evidence of some degree of contrast enhancement. Surgical management was either resection (51%) or biopsy (49%) and postoperative radiotherapy was used in patients with unfavorable prognostic features. The median OS and PFS were 85 months (range 2-98 months) and 36 months (95% confidence interval [95% CI] 27-45 months), respectively. Surgical resection (P < 0.001; hazard ratio [HR] 5.072; 95% CI 2.050-12.550), absence of contrast enhancement (P = 0.006; HR 3.180; 95% CI 1.403-7.206), and IDH1 immunopositivity (P = 0.006; HR 3.310; 95% CI 1.416-7.738) were associated with improved OS. Good performance status (P = 0.005; HR 5.965; 95% CI 1.710-20.804) and absence of contrast enhancement (P < 0.001; HR 3.446; 95% CI 1.883-6.304) were associated with improved PFS.

CONCLUSIONS

Patients with World Health Organization grade II astrocytomas have better overall survival if their tumor is nonenhancing, amenable to surgical resection, and exhibits the IDH1 mutation. These factors should be used to guide patient management and inform prognosis.

Clinical experience of glioma surgery using "tailed bullet": overcoming the limitations of conventional neuro-navigation guided surgery

PURPOSE

Although conventional neuro-navigation is a useful tool for image-guided glioma surgery, there are some limitations, such as brain shift. We introduced our methods using an identifiable marker, a "tailed bullet", to overcome the limitation of conventional neuro-navigation. A tailed bullet is an identifiable tumor location marker that determines the extent of a resection and we have introduced our technique and reviewed the clinical results.

MATERIALS AND METHODS

We have developed and used "tailed bullets" for brain tumor surgery. They were inserted into the brain parenchyma or the tumor itself to help identify the margin of tumor. We retrospectively reviewed surgically resected glioma cases using "tailed bullet". Total 110 gliomas included in this study and it contains WHO grade 2, 3, and 4 glioma was 14, 36, and 60 cases, respectively.

RESULTS

Gross total resection (GTR) was achieved in 71 patients (64.5%), subtotal resection in 36 patients (32.7%), and partial resection in 3 patients (2.7%). The overall survival (OS) duration of grade 3 and 4 gliomas were 20.9 (range, 1.2-82.4) and 13.6 months (range, 1.4-173.4), respectively. Extent of resection (GTR), younger age, and higher initial Karnofsky Performance Status (KPS) score were related to longer OS for grade-4 gliomas. There was no significant adverse event directly related to the use of tailed bullets.

CONCLUSION

Considering the limitations of conventional neuro-navigation methods, the tailed bullets could be helpful during glioma resection. We believe this simple method is an easily accessible technique and overcomes the limitation of the brain shift from the conventional neuro-navigation. Further studies are needed to verify the clinical benefits of using tailed bullets.

ASYMMETRIC CELL DIVISION: IMPLICATIONS FOR GLIOMA DEVELOPMENT AND TREATMENT

Glioma is a heterogeneous disease process with differential histology and treatment response. It was previously thought that the histological features of glial tumors indicated their cell of origin. However, the discovery of continuous neuro-gliogenesis in the normal adult brain and the identification of brain tumor stem cells within glioma have led to the hypothesis that these brain tumors originate from multipotent neural stem or progenitor cells, which primarily divide asymmetrically during the postnatal period. Asymmetric cell division allows these cell types to concurrently self-renew whilst also producing cells for the differentiation pathway. It has recently been shown that increased symmetrical cell division, favoring the self-renewal pathway, leads to oligodendroglioma formation from oligodendrocyte progenitor cells. In contrast, there is some evidence that asymmetric cell division maintenance in tumor stem-like cells within astrocytoma may lead to acquisition of treatment resistance. Therefore cell division mode in normal brain stem and progenitor cells may play a role in setting tumorigenic potential and the type of tumor formed. Moreover, heterogeneous tumor cell populations and their respective cell division mode may confer differential sensitivity to therapy. This review aims to shed light on the controllers of cell division mode which may be therapeutically targeted to prevent glioma formation and improve treatment response.