Is There an Indication for Intraoperative MRI in Subtotal Resection of Glioblastoma? A Multicenter Retrospective Comparative Analysis

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.

Review of Intraoperative Adjuncts for Maximal Safe Resection of Gliomas and Its Impact on Outcomes

Maximal safe resection is the mainstay of treatment in the neurosurgical management of gliomas, and preserving functional integrity is linked to favorable outcomes. How these modalities differ in their effectiveness on the extent of resection (EOR), survival, and complications remains unknown. A systematic literature search was performed with the following inclusion criteria: published between 2005 and 2022, involving brain glioma surgery, and including one or a combination of intraoperative modalities: intraoperative magnetic resonance imaging (iMRI), awake/general anesthesia craniotomy mapping (AC/GA), fluorescence-guided imaging, or combined modalities. Of 525 articles, 464 were excluded and 61 articles were included, involving 5221 glioma patients, 7(11.4%) articles used iMRI, 21(36.8%) used cortical mapping, 15(24.5%) used 5-aminolevulinic acid (5-ALA) or fluorescein sodium, and 18(29.5%) used combined modalities. The heterogeneity in reporting the amount of surgical resection prevented further analysis. Progression-free survival/overall survival (PFS/OS) were reported in 18/61(29.5%) articles, while complications and permanent disability were reported in 38/61(62.2%) articles. The reviewed studies demonstrate that intraoperative adjuncts such as iMRI, AC/GA mapping, fluorescence-guided imaging, and a combination of these modalities improve EOR. However, PFS/OS were underreported. Combining multiple intraoperative modalities seems to have the highest effect compared to each adjunct alone.

The prognosis of glioblastoma: a large, multifactorial study

OBJECTIVE

Glioblastoma is the most common and fatal primary brain tumor in adults. Even with maximal resection and a series of postoperative adjuvant treatments, the median overall survival (OS) of glioblastoma patients remains approximately 15 months. The Huashan Hospital glioma bank contains more than 2000 glioma tissue samples with long-term follow-up data; almost half of these samples are from glioblastoma patients. Several large glioma databases with long-term follow-up data have reported outcomes of glioblastoma patients from countries other than China. We investigated the prognosis of glioblastoma patients in China and compared the survival outcomes among patients from different databases.

METHODS

The data for 967 glioblastoma patients who underwent surgery at Huashan Hospital and had long-term follow-up records were obtained from our glioma registry (diagnosed from 29 March 2010, through 7 June 2017). Patients were eligible for inclusion if they underwent surgical resection for newly diagnosed glioblastomas and had available data of survival and personal information. Data of 778 glioblastoma patients were collected from three separate online databases (448 patients from The Cancer Genome Atlas (TCGA, https://cancergenome.nih.gov), 191 from REpository for Molecular BRAin Neoplasia DaTa (REMBRANDT) database (GSE108476) and 132 from data set GSE16011(Hereafter called as the French database). We compared the prognosis of glioblastoma patients from records among the different databases and the changes in survival outcomes of glioblastoma patients from Huashan Hospital over an 8-year period.

RESULTS

The median OS of glioblastoma patients was 16.3 (95% CI: 15.4-17.2) months for Huashan Hospital, 13.8 (95% CI: 12.9-14.9) months for TCGA, 19.3 (95% CI: 17.0-20.0) months for the REMBRANDT database, and 9.1 months for the French database. The median OS of glioblastoma patients from Huashan Hospital improved from 15.6 (2010-2013, 95% CI: 14.4-16.6) months to 18.2 (2014-2017, 95% CI: 15.8-20.6) months over the study period (2010-2017). In addition, the prognosis of glioblastoma patients with total resection was significantly better than that of glioblastoma patients with sub-total resection or biopsy.

CONCLUSIONS

Our study confirms that treatment centered around maximal surgical resection brought survival benefits to glioblastoma patients after adjusting to validated prognostic factors. In addition, an improvement in prognosis was observed among glioblastoma patients from Huashan Hospital over the course of our study. We attributed it to the adoption of a new standard of neurosurgical treatment on the basis of neurosurgical multimodal technologies. Even though the prognosis of glioblastoma patients remains poor, gradual progress is being made.

Intraoperative Magnetic Resonance Imaging for Low-Grade and High-Grade Gliomas: What Is the Evidence? A Meta-Analysis

BACKGROUND

The benefit of intraoperative magnetic resonance imaging (iMRI) in gliomas remains unclear. We performed a meta-analysis of outcomes with iMRI-guided surgery in high-grade gliomas (HGGs) and low-grade gliomas (LGGs).

METHODS

Databases were searched until November 29, 2018 for randomized controlled trials (RCTs) and observational studies (OBS) comparing iMRI use with conventional neurosurgery. Pooled risk ratios (RRs) or hazard ratios were evaluated with the random-effects model. Outcomes included extent of resection (EOR), gross total resection (GTR), progression-free survival (PFS), overall survival (OS), and length of surgery (LOS), stratified by study design and glioma grade.

RESULTS

Fifteen articles (3 RCTs and 12 OBS) were included. In RCTs, GTR was higher in iMRI compared with conventional neurosurgery (RR, 1.42; 95% confidence interval [CI], 1.17-1.73; I², 7%) overall, for LGGs (1.91; 95% CI, 1.19-3.06), but not HGGs (1.24; 95% CI, 0.89-1.73), with no difference in EOR, PFS, OS, and LOS. For OBS, GTR was higher (RR, 1.65; 95% CI, 1.43-1.90; I², 4%) overall, and for LGGs (1.63; 95% CI, 1.17-2.28; I², 0%) and HGGs (1.62; 95% CI, 1.36-1.92; I², 19%). EOR was greater with iMRI (6%; 95% CI, 4%-8%; I², 44%) overall, in LGGs (5%; 95% CI, 2%-8%; I², 37%) and HGGs (7%; 95% CI, 4%-10%; I², 13%). There was no difference in PFS, OS, and LOS with iMRI.

CONCLUSIONS

IMRI use improved GTR in gliomas, including LGGs. However, no PFS and OS benefit was shown in the meta-analysis.

Congress of neurological surgeons systematic review and evidence-based guidelines update on the role of emerging developments in the management of newly diagnosed glioblastoma

TARGET POPULATION

These recommendations apply to adult patients with newly diagnosed or suspected glioblastoma.

IMAGING

Question What imaging modalities are in development that may be able to provide improvements in diagnosis, and therapeutic guidance for individuals with newly diagnosed glioblastoma?

RECOMMENDATION

Level III: It is suggested that techniques utilizing magnetic resonance imaging for diffusion weighted imaging, and to measure cerebral blood and magnetic spectroscopic resonance imaging of N-acetyl aspartate, choline and the choline to N-acetyl aspartate index to assist in diagnosis and treatment planning in patients with newly diagnosed or suspected glioblastoma.

SURGERY

Question What new surgical techniques can be used to provide improved tumor definition and resectability to yield better tumor control and prognosis for individuals with newly diagnosed glioblastoma?

RECOMMENDATIONS

Level II: The use of 5-aminolevulinic acid is recommended to improve extent of tumor resection in patients with newly diagnosed glioblastoma. Level II: The use of 5-aminolevulinic acid is recommended to improve median survival and 2 year survival in newly diagnosed glioblastoma patients with clinical characteristics suggesting poor prognosis. Level III: It is suggested that, when available, patients be enrolled in properly designed clinical trials assessing the value of diffusion tensor imaging in improving the safety of patients with newly diagnosed glioblastoma undergoing surgery.

NEUROPATHOLOGY

Question What new pathology techniques and measurement of biomarkers in tumor tissue can be used to provide improved diagnostic ability, and determination of therapeutic responsiveness and prognosis for patients with newly diagnosed glioblastomas?

RECOMMENDATIONS

Level II: Assessment of tumor MGMT promoter methylation status is recommended as a significant predictor of a longer progression free survival and overall survival in patients with newly diagnosed with glioblastoma. Level II: Measurement of tumor expression of neuron-glia-2, neurofilament protein, glutamine synthetase and phosphorylated STAT3 is recommended as a predictor of overall survival in patients with newly diagnosed with glioblastoma. Level III: Assessment of tumor IDH1 mutation status is suggested as a predictor of longer progression free survival and overall survival in patients with newly diagnosed with glioblastoma. Level III: Evaluation of tumor expression of Phosphorylated Mitogen-Activated Protein Kinase protein, EGFR protein, and Insulin-like Growth Factor-Binding Protein-3 is suggested as a predictor of overall survival in patients with newly diagnosed with glioblastoma.

RADIATION

Question What radiation therapy techniques are in development that may be used to provide improved tumor control and prognosis for individuals with newly diagnosed glioblastomas?

RECOMMENDATIONS

Level III: It is suggested that patients with newly diagnosed glioblastoma undergo pretreatment radio-labeled amino acid tracer positron emission tomography to assess areas at risk for tumor recurrence to assist in radiation treatment planning. Level III: It is suggested that, when available, patients be with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of radiation dose escalation, altered fractionation, or new radiation delivery techniques.

CHEMOTHERAPY

Question What emerging chemotherapeutic agents or techniques are available to provide better tumor control and prognosis for patients with newly diagnosed glioblastomas?

RECOMMENDATION

Level III: As no emerging chemotherapeutic agents or techniques were identified in this review that improved tumor control and prognosis it is suggested that, when available, patients with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of chemotherapy.

MOLECULAR AND TARGETED THERAPY

Question What new targeted therapy agents are available to provide better tumor control and prognosis for individuals with newly diagnosed glioblastomas?

RECOMMENDATION

Level III: As no new molecular and targeted therapies have clearly provided better tumor control and prognosis it is suggested that, when available, patients with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of molecular and targeted therapies IMMUNOTHERAPY: Question What emerging immunotherapeutic agents or techniques are available to provide better tumor control and prognosis for patients with newly diagnosed glioblastomas?

RECOMMENDATION

Level III: As no immunotherapeutic agents have clearly provided better tumor control and prognosis it is suggested that, when available, patients with newly diagnosed glioblastomas be enrolled in properly designed clinical trials of immunologically-based therapies.

NOVEL THERAPIES

Question What novel therapies or techniques are in development to provide better tumor control and prognosis for individuals with newly diagnosed glioblastomas?

RECOMMENDATIONS

Level II: The use of tumor-treating fields is recommended for patients with newly diagnosed glioblastoma who have undergone surgical debulking and completed concurrent chemoradiation without progression of disease at the time of tumor-treating field therapy initiation. Level II: It is suggested that, when available, enrollment in properly designed studies of vector containing herpes simplex thymidine kinase gene and prodrug therapies be considered in patients with newly diagnosed glioblastoma.

Intraoperative MRI for newly diagnosed supratentorial glioblastoma: a multicenter-registry comparative study to conventional surgery

OBJECTIVE

Intraoperative MRI (iMRI) is used in the surgical treatment of glioblastoma, with uncertain effects on outcomes. The authors evaluated the impact of iMRI on extent of resection (EOR) and overall survival (OS) while controlling for other known and suspected predictors.

METHODS

A multicenter retrospective cohort of 640 adult patients with newly diagnosed supratentorial glioblastoma who underwent resection was evaluated. iMRI was performed in 332/640 cases (51.9%). Reviews of MRI features and tumor volumetric analysis were performed on a subsample of cases (n = 286; 110 non-iMRI, 176 iMRI) from a single institution.

RESULTS

The median age was 60.0 years (mean 58.5 years, range 20.5-86.3 years). The median OS was 17.0 months (95% CI 15.6-18.4 months). Gross-total resection (GTR) was achieved in 403/640 cases (63.0%). Kaplan-Meier analysis of 286 cases with volumetric analysis for EOR (grouped into 100%, 95%-99%, 80%-94%, and 50%-79%) showed longer OS for 100% EOR compared to all other groups (p < 0.01). Additional resection after iMRI was performed in 104/122 cases (85.2%) with initial subtotal resection (STR), leading to a 6.3% mean increase in EOR and a 2.2-cm3 mean decrease in tumor volume. For iMRI cases with volumetric analysis, the GTR rate increased from 54/176 (30.7%) on iMRI to 126/176 (71.5%) postoperatively. The EOR was significantly higher in the iMRI group for intended GTR and STR groups (p = 0.02 and p < 0.01, respectively). Predictors of GTR on multivariate logistic regression included iMRI use and intended GTR. Predictors of shorter OS on multivariate Cox regression included older age, STR, isocitrate dehydrogenase 1 (IDH1) wild type, no O 6-methylguanine DNA methyltransferase (MGMT) methylation, and no Stupp therapy. iMRI was a significant predictor of OS on univariate (HR 0.82, 95% CI 0.69-0.98; p = 0.03) but not multivariate analyses. Use of iMRI was not associated with an increased rate of new permanent neurological deficits.

CONCLUSIONS

GTR increased OS for patients with newly diagnosed glioblastoma after adjusting for other prognostic factors. iMRI increased EOR and GTR rate and was a significant predictor of GTR on multivariate analysis; however, iMRI was not an independent predictor of OS. Additional supporting evidence is needed to determine the clinical benefit of iMRI in the management of glioblastoma.

Fluorescence guided surgery by 5-ALA and intraoperative MRI in high grade glioma: a systematic review

PURPOSE

Fluorescence guided surgery by 5-aminolevulinic acid (5-ALA) and intraoperative MRI (iMRI) are currently the most important intraoperative imaging techniques in high grade glioma (HGG) surgery. Few comparative studies exist for these techniques. This review aims to systematically compare 5-ALA and iMRI assisted surgery based on the current literature and discuss the potential impact of a combined use of both techniques.

METHODS

A systematic literature search based on preferred reporting items for systematic reviews and meta-analysis was performed concerning accuracy of tumor detection; extent of resection; neurological deficits (ND); Quality of life (QoL); usability and combined use of both techniques. Original clinical articles on HGG published until March 31st were screened.

RESULTS

169 publications were screened, 81 were eligible and 22 were finally included in the review using. Overall, there is evidence that both imaging techniques improve gross total resection rate in non-eloquent lesions. Imaging results do not correlate at the border zone of a HGG. 5-ALA and contrast-enhanced iMRI seem to have a supplementary effect in tumor detection. Overall, both imaging techniques alone or combined do not seem to increase rate of permanent ND or decrease QoL in HGG surgery when used with intraoperative monitoring/mapping.

CONCLUSION

Based on the currently available literature no superiority of one technique over the other can be found in the most important outcome parameters. Based on the available information a combined use of 5-ALA and iMRI seems very promising to achieve a resection beyond gadolinium-enhancement. However, only low quality of evidence exists for this approach.

Anesthetic challenges and outcomes for procedures in the intraoperative magnetic resonance imaging suite: A systematic review

BACKGROUND AND OBJECTIVE

Hybrid operating room suites with intraoperative magnetic resonance imaging enable image guided surgery in a fully functional operating room environment. While this environment creates challenges to anesthetic care, the effects on anesthetic adverse events and outcomes are largely unknown. This systematic scoping review aims to map the existing knowledge about anesthetic care in advanced imaging hybrid operating rooms.

METHODS

A broad-based literature search was performed using the PubMed (Medline), Embase, Cochrane Library, Web of Science, and Google Scholar databases. References published in English between January 1994 and August 2017 were included. Quality of evidence was assessed using the GRADE guidelines.

RESULTS

Forty-seven manuscripts were eligible for data collection. Adverse events were heterogeneously defined across 17 manuscripts and occurred in 0 to 100% (quality of evidence mostly very low). Monitoring difficulty was reported in 4 manuscripts of very low data quality. Interference between the magnet and the electrocardiogram was investigated in 2 manuscripts (quality of evidence low and very low, respectively). None of the reported events appeared to result in long-term patient harm. Author recommendations or a narrative review of the literature were provided in 40 manuscripts. Common safety concerns included lower equipment reliability, inaccessibility of the patient and airway, and the relative isolation of the suite (in relationship to other anesthesia care areas). Most authors also emphasized the importance of safety checklists, protocols, and provider training.

DISCUSSION

While intraoperative magnetic resonance imaging hybrid operating rooms are increasingly utilized, the existing literature does not allow estimating adverse event rates in this location. Prospective studies quantifying the effect of the environment on anesthesia outcomes are lacking. Despite this, there is a broad consensus regarding the anesthetic and safety concerns. More research is needed to inform practice standards and training requirements for this challenging environment.