5-Aminolevulinic acid-guided resection improves the overall survival of patients with glioblastoma-a comparative cohort study of 343 patients

Selective Photothermal Eradication of Glioblastoma Cells Coexisting with Astrocytes by Anti-EGFR-Coated Raman Tags

Glioblastoma (GBM) is an aggressive and fatal tumor. The infiltrative spread of GBM cells hinders gross total resection. The residual GBM cells are significantly associated with survival and recurrence. Therefore, a theranostic method that can enhance the contrast between residual GBM and normal astrocyte (AS) cells and selectively eradicate GBM cells is highly desired. In this report, GBM and normal astrocyte cells are both cultured in the same microplate well to imitate a coexistence environment and treated with Raman tags functionalized by anti-EGFR. Compared to AS cells, GBM cells show 25% higher Raman emission, and their cell death rate increases by a factor of 2. These results demonstrate the potential for selective eradication of the residual GBM cells guided by robust Raman signals after the primary GBM surgery.

Recent Advances of Nitrobenzoselenadiazole for Imaging and Therapy

The development and practical applications of multifunctional organic fluorophores have garnered significant attention in translational research in recent years. Among the fluorophores, nitrobenzodioxazole (NBD) has been widely used in various fields due to its small size and neutral character, both of which are advantageous for biorelated applications. However, NBD presents some limitations, including (1) suboptimal photophysical properties for in vivo applications and (2) its monofunctional nature, which restricts its use in fluorescence-based bioimaging and sensing. To overcome these challenges, recent research has focused on the development of nitrobenzoselenadiazole (NBSD) derivatives, a selenium analog of NBD. In this review article, we systematically summarize recent advancements in the development of NBSD and highlight examples of its application in translational research as a multifunctional organic fluorophore. We also explore the potential applications of NBSD and present representative case studies, providing valuable context for the ongoing development of new NBSD derivatives in the field of fluorophore-related material science.

Toward the Treatment of Glioblastoma Tumors Using Photoactivated Chemotherapy: In Vitro Evaluation of Efficacy and Safety

Glioblastoma multiforme (GBM) is highly aggressive, necessitating new therapies. Photoactivated chemotherapy (PACT) offers a promising approach by activating prodrugs with visible light at the tumor site. This study evaluated the anticancer activity of ruthenium-based PACT compounds in U-87MG glioblastoma cells and their safety in SH-SY5Y neuron-like cells. The compound [3](PF6)2 showed promising light-activated anticancer effects in U-87MG cells, while [1](PF6)2 was inactive, and [2](PF6)2 was nonactivated. Interestingly, in SH-SY5Y cells, light-activated [3](PF6)2 increased cell proliferation, similar to donepezil, without causing cell death. Increased Ca2+ uptake was observed, possibly via interaction with the AMPA receptor, as suggested by docking studies. These findings suggest ruthenium-based PACT compounds may serve as potential treatments for GBM, effectively attacking cancer cells while preserving healthy neuronal cells.

Diffusion changes in minimally invasive parafascicular approach for deep-seated tumours: impact on clinical outcomes

Minimally invasive parafascicular surgery (MIPS) with the use of tubular retractors achieve a safe resection in deep seated tumours. Diffusion changes noted on postoperative imaging; the significance and clinical correlation of this remains poorly understood. Single centre retrospective cohort study of neuro-oncology patients undergoing MIPS. The impact of surgical approach-transsulcal (TS) versus transgyral (TG) - and respective entry points in clinical and imaging outcomes was assessed. 82 patients (35 male; 47 female, average age 43.94 ± 22.85 years) were included. 84% presented with neurological deficit and glioblastoma was the commonest diagnosis (38.24%). Surgical approach was not relevant for the number of patients that showed postoperative peritubular injury (TS: 20 (37.74%) versus TG: 8 (27.59%), p = 0.354) or its volume (TS: 0.95 ± 1.82 cc versus TG: 0.43 ± 1.32 cc, p = 0.1435). When adjusted for preoperative volume and depth of tumour, TS approach was associated with less diffusion restriction (p = 0.030). Temporal lobe access points had the highest volume of diffusion restriction (temporal lobe-2.50 ± 3.54 cc versus frontal lobe - 1.15 ± 1.53 versus parietal lobe-0.51 ± 0.91 cc, p = 0.0096), particularly in the TS approach (p = 0.0152). Superior motor outcomes were demonstrated in the TS versus the TG approach (postoperative improvement: TS: 14.63% versus TG: 6.9%, p = 0.015), especially for parietal approaches (p = 0.039). TS approach was related with a significantly decreased length of stay (TS-11.67 ± 14.19 days versus TG - 23.97 ± 18.01 days, p = 0.001). Transsulcal approach demonstrated a better motor outcome profile, particularly in parietal lobe, and shorter length of stay. The superior temporal sulcus was more susceptible to ischaemic changes. Therefore, transgyral route can be considered in temporal lobe MIPS.

Emerging nanoplatforms towards microenvironment-responsive glioma therapy

Gliomas are aggressive intracranial tumors of the central nervous system with a poor prognosis, high risk of recurrence, and low survival rates. Radiation, surgery, and chemotherapy are traditional cancer therapies. It is very challenging to accurately image and differentiate the malignancy grade of gliomas due to their heterogeneous and infiltrating nature and the obstruction of the blood-brain barrier. Imaging plays a crucial role in gliomas which significantly plays an important role in the accuracy of the diagnosis followed by any subsequent surgery or therapy. Other diagnostic methods (such as biopsies or surgery) are often very invasive. Preoperative imaging and intraoperative image-guided surgery perform the most significant safe resection. In recent years, the rapid growth of nanotechnology has opened up new avenues for glioma diagnosis and treatment. For better therapeutic efficacy, developing microenvironment-responsive nanoplatforms, including novel nanotherapeutic platforms of sonodynamic therapy, photodynamic therapy, and photothermal treatments, are employed for improved patient survival and better clinical control outcome. In this review recent advancement of multifunctional nanoplatforms leading toward treatment of glioma is discussed.

Clinical research framework proposal for ketogenic metabolic therapy in glioblastoma

Glioblastoma (GBM) is the most aggressive primary brain tumor in adults, with a universally lethal prognosis despite maximal standard therapies. Here, we present a consensus treatment protocol based on the metabolic requirements of GBM cells for the two major fermentable fuels: glucose and glutamine. Glucose is a source of carbon and ATP synthesis for tumor growth through glycolysis, while glutamine provides nitrogen, carbon, and ATP synthesis through glutaminolysis. As no tumor can grow without anabolic substrates or energy, the simultaneous targeting of glycolysis and glutaminolysis is expected to reduce the proliferation of most if not all GBM cells. Ketogenic metabolic therapy (KMT) leverages diet-drug combinations that inhibit glycolysis, glutaminolysis, and growth signaling while shifting energy metabolism to therapeutic ketosis. The glucose-ketone index (GKI) is a standardized biomarker for assessing biological compliance, ideally via real-time monitoring. KMT aims to increase substrate competition and normalize the tumor microenvironment through GKI-adjusted ketogenic diets, calorie restriction, and fasting, while also targeting glycolytic and glutaminolytic flux using specific metabolic inhibitors. Non-fermentable fuels, such as ketone bodies, fatty acids, or lactate, are comparatively less efficient in supporting the long-term bioenergetic and biosynthetic demands of cancer cell proliferation. The proposed strategy may be implemented as a synergistic metabolic priming baseline in GBM as well as other tumors driven by glycolysis and glutaminolysis, regardless of their residual mitochondrial function. Suggested best practices are provided to guide future KMT research in metabolic oncology, offering a shared, evidence-driven framework for observational and interventional studies.

In Situ Light-Source Delivery During 5-Aminulevulinic Acid-Guided High-Grade Glioma Resection: Spatial, Functional and Oncological Informed Surgery

BACKGROUND/OBJECTIVES

5-aminulevulinic acid (5-ALA)-guided surgery for high-grade gliomas remains a challenge in neuro-oncological surgery. Inconsistent fluorescence visualisation, subjective quantification and false negatives due to blood, haemostatic agents or optical impediments from the external light source are some of the limitations of the present technology.

METHODS

The preliminary results from this single-centre retrospective study are presented from the first 35 patients operated upon with the novel Nico Myriad Spectra System©. The microdebrider (Myriad) with an additional in situ light system (Spectra) can alternately provide white and blue light (405 nm) to within 15 mm of the tissue surface to enhance the morphology of the anatomical structures and the fluorescence of the pathological tissues.

RESULTS

A total of 35 patients were operated upon with this new technology. Eight patients (22.85%) underwent tubular retractor-assisted minimally invasive parafascicular surgery (tr-MIPS). The majority had high-grade gliomas (68.57%). Fluorescence was identified in 30 cases (85.71%), with residual fluorescence in 11 (36.66%). The main applications were better white-blue light alternation and visualisation during tr-MIPS, increase in the extent of resection at the border of the cavity, identification of satellite lesions in multifocal pathology, the differentiation between radionecrosis and tumour recurrence in redo surgery and the demarcation between normal ependyma versus pathological ependyma in tumours infiltrating the subventricular zone.

CONCLUSIONS

This proof-of-concept study confirms that the novel in situ light-source delivery technology integrated with the usual intraoperative armamentarium provides a spatially, functionally and oncologically informed framework for glioblastoma surgery. It allows for the enhancement of the morphology of anatomical structures and the fluorescence of pathological tissues, increasing the extent of resection and, possibly, the prognosis for patients with high-grade gliomas.

Safety, efficacy, and side effects of sodium fluorescein-aided resection of glioblastoma: a quasi-experimental study

Background

The use of fluorescein sodium (FS) as a surgical adjunct in glioblastoma resection has shown promise in improving tumor visualization and resection outcomes. This study aimed to evaluate the safety, efficacy, and side effects of FS-aided resection in patients with glioblastoma.

Methods

This is a prospective, single-center cohort study conducted at Ibrahim Cardiac Hospital and Research Institute from September 2021 to November 2023. Twelve patients with histologically confirmed glioblastoma underwent FS-guided resection. All participants received an intravenous dose of FS (5 mg/kg body weight) ~30 min before surgery. The study follows a quasi-experimental design, focusing on the outcomes of FS-aided surgery without a control group. Patients were selected based on specific inclusion and exclusion criteria, and all surgeries were performed by a single experienced neurosurgeon. The extent of tumor resection was classified as gross total resection (GTR), near-total resection (NTR), or partial resection (PR).

Results

Gross total resection (GTR) was achieved in 66.6% of patients, near total resection (NTR) in 16.6%, and subtotal resection (STR) in 16.6%. No significant adverse effects were observed except for a single case of postoperative seizure, which was managed without long-term consequences. All patients showed normal liver and kidney function tests postoperatively. The low-dose FS protocol demonstrated both a high rate of GTR and a favorable safety profile, with only minor, transient side effects such as temporary yellow discoloration of the skin, sclera, and urine. No severe or long-term complications related to FS were observed during the follow-up period, which had a median duration of 13.4 months.

Conclusion

FS appears to be a safe and effective aid in glioblastoma resection, achieving high rates of GTR with minimal side effects. The findings suggest that FS, particularly at a low dose, is a viable, cost-effective alternative to other fluorescent markers, especially in settings where resource constraints may limit the use of more expensive options like 5-ALA.

The peritumoral brain zone in glioblastoma: a review of the pretreatment approach

Glioblastomas are the most common and aggressive form of malignant primary brain tumors in adults. The standard treatment is surgical resection followed by radiotherapy and chemotherapy. Despite optimal treatment methods, the prognosis for patients remains poor. Preoperative determination of glioblastoma margins remains beneficial for the complete removal of the tumor mass. Radiotherapy is essential for post-surgery treatment, but radioresistance is a significant challenge contributing to high mortality rates. Advanced imaging technologies are used to analyze the changes in the peritumoral brain zone (PTZ). Consequently, they may lead to the development of novel therapeutic options, especially targeting the marginal parts of a tumor, which could improve the prognosis of glioblastoma patients. The clinical presentation of glioblastoma is heterogeneous and mostly depends on the location and size of a tumor. Glioblastomas are characterized by both intratumoral cellular heterogeneity and an extensive, diffuse infiltration into the normal tissue bordering a tumor called the PTZ. Neuroimaging techniques, such as diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), perfusion-weighted imaging (PWI), proton magnetic resonance spectroscopy (1H MRS), and chemical exchange saturation transfer (CEST) are useful methods in the evaluation of the tumor infiltration and thus the resection margin.

Intraoperative glioblastoma surgery-current challenges and clinical trials: An update

Surgical excision is an important part of the multimodal therapy strategy for patients with glioblastoma, a very aggressive and invasive brain tumor. While major advances in surgical methods and technology have been accomplished, numerous hurdles remain in the field of glioblastoma surgery. The purpose of this literature review is to offer a thorough overview of the current challenges in glioblastoma surgery. We reviewed the difficulties associated with tumor identification and visualization, resection extent, neurological function preservation, tumor margin evaluation, and inclusion of sophisticated imaging and navigation technology. Understanding and resolving these challenges is critical in order to improve surgical results and, ultimately, patient survival.

Review of Novel Surgical, Radiation, and Systemic Therapies and Clinical Trials in Glioblastoma

Glioblastoma (GBM) is the most common malignant primary brain tumor in adults. Despite an established standard of care including surgical resection, radiation therapy, and chemotherapy, GBM unfortunately is associated with a dismal prognosis. Therefore, researchers are extensively evaluating avenues to expand GBM therapy and improve outcomes in patients with GBM. In this review, we provide a broad overview of novel GBM therapies that have recently completed or are actively undergoing study in clinical trials. These therapies expand across medical, surgical, and radiation clinical trials. We additionally review methods for improving clinical trial design in GBM.

Current Status and Future Perspective in Glioma Invasion Research

Glioblastoma (GBM) is the most malignant brain tumor in adults and shows an extremely poor prognosis, with a median survival of 15 months [...].

Glioblastoma Therapy: Past, Present and Future

Glioblastoma (GB) stands out as the most prevalent and lethal form of brain cancer. Although great efforts have been made by clinicians and researchers, no significant improvement in survival has been achieved since the Stupp protocol became the standard of care (SOC) in 2005. Despite multimodality treatments, recurrence is almost universal with survival rates under 2 years after diagnosis. Here, we discuss the recent progress in our understanding of GB pathophysiology, in particular, the importance of glioma stem cells (GSCs), the tumor microenvironment conditions, and epigenetic mechanisms involved in GB growth, aggressiveness and recurrence. The discussion on therapeutic strategies first covers the SOC treatment and targeted therapies that have been shown to interfere with different signaling pathways (pRB/CDK4/RB1/P16ink4, TP53/MDM2/P14arf, PI3k/Akt-PTEN, RAS/RAF/MEK, PARP) involved in GB tumorigenesis, pathophysiology, and treatment resistance acquisition. Below, we analyze several immunotherapeutic approaches (i.e., checkpoint inhibitors, vaccines, CAR-modified NK or T cells, oncolytic virotherapy) that have been used in an attempt to enhance the immune response against GB, and thereby avoid recidivism or increase survival of GB patients. Finally, we present treatment attempts made using nanotherapies (nanometric structures having active anti-GB agents such as antibodies, chemotherapeutic/anti-angiogenic drugs or sensitizers, radionuclides, and molecules that target GB cellular receptors or open the blood-brain barrier) and non-ionizing energies (laser interstitial thermal therapy, high/low intensity focused ultrasounds, photodynamic/sonodynamic therapies and electroporation). The aim of this review is to discuss the advances and limitations of the current therapies and to present novel approaches that are under development or following clinical trials.

Resection of positive tissue on methionine-PET is associated with improved survival in glioblastomas

BACKGROUND AND PURPOSE

The volume of excised tumor in contrast-enhanced areas evaluated via magnetic resonance imaging is known to have a strong influence on the survival of patients with glioblastoma (GBM). In this study, we investigated the effect of tumor resection on the survival of patients with GBM in the 11 C-methionine (MET) accumulation area using MET-positron emission tomography (MET-PET).

METHODS

A total of 26 patients (median age, 69 years; 15 males) who had undergone tumor resection and MET-PET before and after surgery, after being newly diagnosed with GBM, were included in the study. MET-PET before and after tumor resection were compared. The association between the decrease in the maximum standardized uptake value (SUV) of the tumor divided by the normal cortical mean SUV (%; ΔT/N), the MET extent of resection (MET-EOR) from the % reduction in the MET accumulation area (%), and residual MET accumulation area (in cm3 ; MET-residual tumor volume [RTV]), as well as the survival time of patients with GBM, were evaluated via univariate analysis.

RESULTS

ΔT/N were positively associated with survival (hazard ratio [HR], 0.98 [95% confidence interval (CI), 0.97-0.99], p = .02). MET-RTV revealed a negative association with survival (HR, 1.02 [95% CI, 1.01-1.04], p = .04). Additionally, MET-EOR showed a strong trend with survival (HR, 0.99 [95% CI, 0.97-1.01], p = .06).

CONCLUSIONS

Surgical resection of MET-accumulated areas in GBM significantly prolongs the survival of patients with GBM. However, a prospective large-scale multicenter study is needed to confirm our findings.

Intraoperative Fluorophores: An Update on 5-Aminolevulinic Acid and Sodium Fluorescein in Resection of Tumors of the Central Nervous System and Metastatic Lesions-A Systematic Review and Meta-Analysis

INTRODUCTION

Recent advances in tumor visualization have improved the extent of resection (EOR) of primary and secondary tumors of the central nervous system, while limiting the morbidity and mortality of the surgery. One area of recent interest has been the use of intraoperative fluorophores for tumor visualization such as 5-aminolevulinic acid (5-ala) and sodium fluorescein. We performed a systematic review and meta-analysis on the utility of fluorophore administration and EOR with each fluorophore to update the current literature.

METHODS

We conducted a systematic review and meta-analysis on the use of intraoperative 5-ala or fluorescein between 2021 and 2023 using the PubMed, SCOPUS, and WOS databases. The initial search yielded 8688 results. After inclusion and exclusion criteria were met, 44 studies remained for review. A meta-analysis was performed to compare the EOR between studies for each fluorophore and to compare the presence of intraoperative fluorescence by tumor type. Odds ratios (OR) were calculated for gross total resection (GTR), and two-way ANOVA tests were performed to compare rates of intraoperative fluorescence by fluorophore and tumor type.

RESULTS

In all groups except low-grade glioma, fluorescence was present after 5-ala administration; fluorescence was present for all groups after fluorescein administration. Two-way ANOVA analysis for both fluorophores demonstrated no statistically significant difference in presence of fluorescence between type of tumor resected. Meta-analysis of EOR did show a higher, but not significant, rate of GTR in the 5-ala group compared to controls (OR = 1.29, 95% CI = 0.49; 3.37). In the fluorescein group, there were statistically significant higher odds of GTR compared to the control group (OR = 2.10, 95% CI = 1.43; 3.10, I2 = 0%).

CONCLUSIONS

Both 5-ala and sodium fluorescein demonstrated intraoperative fluorescence among various tumor types in both cranial and spinal tumors, as well as efficacy in improving EOR. Both fluorophores merit further investigation for use in surgery of CNS tumors.

MGMT Promoter Methylation: Prognostication beyond Treatment Response

MGMT promoter methylation is related to the increased sensitivity of tumour tissue to chemotherapy with temozolomide (TMZ) and thus to improved patient survival. However, it is unclear how the extent of MGMT promoter methylation affects outcomes. In our study, a single-centre retrospective study, we explore the impact of MGMT promoter methylation in patients with glioblastoma who were operated upon with 5-ALA. Demographic, clinical and histology data, and survival rates were assessed. A total of 69 patients formed the study group (mean age 53.75 ± 15.51 years old). Positive 5-ALA fluorescence was noted in 79.41%. A higher percentage of MGMT promoter methylation was related to lower preoperative tumour volume (p = 0.003), a lower likelihood of 5-ALA positive fluorescence (p = 0.041) and a larger extent of resection EoR (p = 0.041). A higher MGMT promoter methylation rate was also related to improved progression-free survival (PFS) and overall survival (OS) (p = 0.008 and p = 0.006, respectively), even when adjusted for the extent of resection (p = 0.034 and p = 0.042, respectively). A higher number of adjuvant chemotherapy cycles was also related to longer PFS and OS (p = 0.049 and p = 0.030, respectively). Therefore, this study suggests MGMT promoter methylation should be considered as a continuous variable. It is a prognostic factor that goes beyond sensitivity to chemotherapy treatment, as a higher percentage of methylation is related not only to increased EoR and increased PFS and OS, but also to lower tumour volume at presentation and a lower likelihood of 5-ALA fluorescence intraoperatively.

Preclinical Studies with Glioblastoma Brain Organoid Co-Cultures Show Efficient 5-ALA Photodynamic Therapy

BACKGROUND

The high recurrence of glioblastoma (GB) that occurs adjacent to the resection cavity within two years of diagnosis urges an improvement of therapies oriented to GB local control. Photodynamic therapy (PDT) has been proposed to cleanse infiltrating tumor cells from parenchyma to ameliorate short long-term progression-free survival. We examined 5-aminolevulinic acid (5-ALA)-mediated PDT effects as therapeutical treatment and determined optimal conditions for PDT efficacy without causing phototoxic injury to the normal brain tissue.

METHODS

We used a platform of Glioma Initiation Cells (GICs) infiltrating cerebral organoids with two different glioblastoma cells, GIC7 and PG88. We measured GICs-5-ALA uptake and PDT/5-ALA activity in dose-response curves and the efficacy of the treatment by measuring proliferative activity and apoptosis.

RESULTS

5-ALA (50 and 100 µg/mL) was applied, and the release of protoporphyrin IX (PpIX) fluorescence measures demonstrated that the emission of PpIX increases progressively until its stabilization at 24 h. Moreover, decreased proliferation and increased apoptosis corroborated the effect of 5-ALA/PDT on cancer cells without altering normal cells.

CONCLUSIONS

We provide evidence about the effectiveness of PDT to treat high proliferative GB cells in a complex in vitro system, which combines normal and cancer cells and is a useful tool to standardize new strategic therapies.

H3 G34-mutant high-grade gliomas: integrated clinical, imaging and pathological characterisation of a single-centre case series

BACKGROUND

Diffuse hemispheric glioma, H3 G34-mutant, is a novel paediatric tumour type in the fifth edition of the WHO classification of CNS tumours associated with an invariably poor outcome. We present a comprehensive clinical, imaging and pathological review of this entity.

METHODS

Patients with confirmed H3 G34R-mutant high-grade glioma were included in a single-centre retrospective cohort study and examined for clinical, radiological and histo-molecular data.

RESULTS

Twelve patients were enrolled in the study - 7 males/5 females; the mean age was 17.5 years (10-57 years). Most patients presented with signs of raised intracranial pressure (8/12). The frontal lobe (60%) was the prevalent location, with a mixed cystic-nodular appearance (10/12) and presence of vascular flow voids coursing through/being encased by the mass (8/12), and all tumours showed cortical invasion. Nine patients had subtotal resection limited by functional margins, two patients underwent supra-total resection, and one patient had biopsy only. 5-ALA was administered to 6 patients, all of whom showed positive fluorescence. Histologically, the tumours showed a marked heterogeneity and aggressive spread along pre-existing brain structures and leptomeninges. In addition to the diagnostic H3 G34R/V mutation, pathogenic variants in TP53 and ATRX genes were found in most cases. Potential targetable mutations in PDGFRA and PIK3CA genes were detected in five cases. The MGMT promoter was highly methylated in half of the samples. Methylation profiling was a useful diagnostic tool and highlighted recurrent structural chromosome abnormalities, such as PDGFRA amplification, CDKN2A/B deletion, PTEN loss and various copy number changes in the cyclin D-CDK4/Rb pathway. Radiochemotherapy was the most common adjuvant treatment (9/12), and the average survival was 19.3 months.

CONCLUSIONS

H3 G34R-mutant hemispheric glioma is a distinct entity with characteristic imaging and pathological features. Genomic landscaping of individual tumours can offer an opportunity to adapt individual therapies and improve patient management.

Maximal Safe Resection in Glioblastoma Surgery: A Systematic Review of Advanced Intraoperative Image-Guided Techniques

Glioblastoma multiforme (GBM) represents the most common and aggressive central nervous system tumor associated with a poor prognosis. The aim of this study was to depict the role of intraoperative imaging techniques in GBM surgery and how they can ensure the maximal extent of resection (EOR) while preserving the functional outcome. The authors conducted a systematic review following PRISMA guidelines on the PubMed/Medline and Scopus databases. A total of 1747 articles were identified for screening. Studies focusing on GBM-affected patients, and evaluations of EOR and functional outcomes with the aid of advanced image-guided techniques were included. The resulting studies were assessed for methodological quality using the Risk of Bias in Systematic Review tool. Open Science Framework registration DOI 10.17605/OSF.IO/3FDP9. Eighteen studies were eligible for this systematic review. Among the selected studies, eight analyzed Sodium Fluorescein, three analyzed 5-aminolevulinic acid, two evaluated IoMRI imaging, two evaluated IoUS, and three evaluated multiple intraoperative imaging techniques. A total of 1312 patients were assessed. Gross Total Resection was achieved in the 78.6% of the cases. Follow-up time ranged from 1 to 52 months. All studies assessed the functional outcome based on the Karnofsky Performance Status scale, while one used the Neurologic Assessment in Neuro-Oncology score. In 77.7% of the cases, the functional outcome improved or was stable over the pre-operative assessment. Combining multiple intraoperative imaging techniques could provide better results in GBM surgery than a single technique. However, despite good surgical outcomes, patients often present a neurocognitive decline leading to a marked deterioration of the quality of life. Advanced intraoperative image-guided techniques can allow a better understanding of the anatomo-functional relationships between the tumor and the surrounding brain, thus maximizing the EOR while preserving functional outcomes.

Case report: 'Photodynamics of Subependymal Giant Cell Astrocytoma with 5-Aminolevulinic acid'

Subependymal Giant Cell Astrocytoma (SEGA) is a common diagnosis in patients with Tuberous Sclerosis. Although surgical treatment is often required, resection may entail a significant risk for cognitive function given the anatomical relation with critical structures such as the fornices and subgenual area. Therefore, target subtotal resections using minimal invasive approaches focused in the higher metabolic areas are valuable options to preserve quality of life while addressing specific problems caused by the tumor, such as hydrocephalus or progressive growth of a specific component of the tumor. In this report, the authors explore the potential role of 5-ALA in the identification of highly metabolic areas during SEGA resection in the context of minimal invasive approaches.

Whole-brain MR-registered cryo-imaging of a porcine-human glioma model to compare contrast agent biodistributions

As rapidly accelerating technology, fluorescence guided surgery (FGS) has the potential to place molecular information directly into the surgeon's field of view by imaging administered fluorescent contrast agents in real time, circumnavigating pre-operative MR registration challenges with brain deformation. The most successful implementation of FGS is 5-ALA-PpIX guided glioma resection which has been linked to improved patient outcomes. While FGS may offer direct in-field guidance, fluorescent contrast agent distributions are not as familiar to the surgical community as Gd-MRI uptake, and may provide discordant information from previous Gd-MRI guidance. Thus, a method to assess and validate consistency between fluorescence-labeled tumor regions and Gd-enhanced tumor regions could aid in understanding the correlation between optical agent fluorescence and Gd-enhancement. Herein, we present an approach for comparing whole-brain fluorescence biodistributions with Gd-enhancement patterns on a voxel-by-voxel basis using co-registered fluorescent cryo-volumes and Gd-MRI volumes. In this initial study, a porcine-human glioma xenograft model was administered 5-ALA-PpIX, imaged with MRI, and euthanized 22 hours following 5-ALA administration. Following euthanization, the extracted brain was imaged with the cryo-macrotome system. After image processing steps and non-rigid, point-based registration, the fluorescence cryo-volume and Gd-MRI volume were compared for similarity metrics including: image similarity, tumor shape similarity, and classification similarity. This study serves as a proof-of-principle in validating our screening approach for quantitatively comparing 3D biodistributions between optical agents and Gd-based agents.

Efficacy, Outcome, and Safety of Elderly Patients with Glioblastoma in the 5-ALA Era: Single Center Experience of More Than 10 Years

Simple Summary

In the next decades, the incidence of patients with glioblastoma (GBM) will markedly increase due to the growth of the elderly population. Despite the increasing incidence of GBM, elderly patients are frequently excluded from clinical studies and thus, only few data are available specifically focusing on the elderly population. In the current study, we aimed to investigate the efficacy, outcome, and safety of surgically-treated GBM including resections and biopsies in the 5-ALA era in a large elderly cohort of altogether 272 patients. Our data of this large elderly cohort demonstrate for the first time the clinical utility and safety of 5-ALA fluorescence in GBM for improved tumor visualization in both resections as well as biopsies. Therefore, we recommend the use of 5-ALA not only in resections, but also in open/stereotactic biopsies to optimize the neurosurgical management of elderly GBM patients.

Abstract

Background: In the next decades, the incidence of patients with glioblastoma (GBM) will increase due to the growth of the elderly population. Fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) is widely applied to achieve maximal safe resection of GBM and is identified as a novel intraoperative marker for diagnostic tissue during biopsies. However, detailed analyses of the use of 5-ALA in resections as well as biopsies in a large elderly cohort are still missing. The aim of this study was thus to investigate the efficacy, outcome, and safety of surgically- treated GBM in the 5-ALA era in a large elderly cohort. Methods: All GBM patients aged 65 years or older who underwent neurosurgical intervention between 2007 and 2019 were included. Data on 5-ALA application, intraoperative fluorescence status, and 5-ALA-related side effects were derived from our databank. In the case of resection, the tumor resectability and the extent of resection were determined. Potential prognostic parameters relevant for overall survival were analyzed. Results: 272 GBM patients with a median age of 71 years were included. Intraoperative 5-ALA fluorescence was applied in most neurosurgical procedures (n = 255/272, 88%) and visible fluorescence was detected in most cases (n = 252/255, 99%). In biopsies, 5-ALA was capable of visualizing tumor tissue by visible fluorescence in all but one case (n = 91/92, 99%). 5-ALA administration did not result in any severe side effects. Regarding patient outcome, smaller preoperative tumor volume (<22.75 cm³), gross total resection, single lesions, improved postoperative neurological status, and concomitant radio-chemotherapy showed a significantly longer overall survival. Conclusions: Our data of this large elderly cohort demonstrate the clinical utility and safety of 5-ALA fluorescence in GBM for improved tumor visualization in both resections as well as biopsies. Therefore, we recommend the use of 5-ALA not only in resections, but also in open/stereotactic biopsies to optimize the neurosurgical management of elderly GBM patients.

Fluorescence-Guided Surgery in the Surgical Treatment of Gliomas: Past, Present and Future

Simple Summary

Gliomas are aggressive central nervous system tumours. The emergence and recent widespread adoption of 5-aminolevulinic acid and fluorescence guided surgery have improved the extent of resection, with implications for improved survival and progression-free survival. This review describes the history, rationale and mechanism behind the use of 5-aminolevulinic acid and fluorescence-guided surgery. We also discuss current limitations and future directions for this important adjunct to glioma surgery. This review aims to provide readers with an up-to-date overview and evidence base on this important topic.

Abstract

Gliomas are central nervous systems tumours which are diffusely infiltrative and difficult to treat. The extent of surgical resection is correlated with improved outcomes, including survival and disease-free progression. Cancerous tissue can be directly visualised intra-operatively under fluorescence by administration of 5-aminolevulinic acid to the patient. The adoption of this technique has allowed surgeons worldwide to achieve greater extents of resection, with implications for improved prognosis. However, there are practical limitations to use of 5-aminolevulinic acid. New adjuncts in the field of fluorescence-guided surgery aim to improve recognition of the interface between tumour and brain with the objective of improving resection and patient outcomes.