Receipt of brachytherapy is an independent predictor of survival in glioblastoma in the Surveillance, Epidemiology, and End Results database

The role of GammaTile in the treatment of brain tumors: a technical and clinical overview

Malignant and benign brain tumors with a propensity to recur continue to be a clinical challenge despite decades-long efforts to develop systemic and more advanced local therapies. GammaTile (GT Medical Technologies Inc., Tempe AZ) has emerged as a novel brain brachytherapy device placed during surgery, which starts adjuvant radiotherapy immediately after resection. GammaTile received FDA clearance in 2018 for any recurrent brain tumor and expanded clearance in 2020 to include upfront use in any malignant brain tumor. More than 1,000 patients have been treated with GammaTile to date, and several publications have described technical aspects of the device, workflow, and clinical outcome data. Herein, we review the technical aspects of this brachytherapy treatment, including practical physics principles, discuss the available literature with an emphasis on clinical outcome data in the setting of brain metastases, glioblastoma, and meningioma, and provide an overview of the open and pending clinical trials that are further defining the efficacy and safety of GammaTile.

Brachytherapy is an effective and safe salvage option for re-irradiation in recurrent glioblastoma (rGBM): A systematic review

PURPOSE

To evaluate the clinical efficacy and toxicity of brachytherapy as a salvage therapy for patients with recurrent glioblastoma (rGBM).

METHODS AND MATERIALS

We searched the PubMed, Embase, and Cochrane libraries from its inception to June 2023, for eligible studies in which patients underwent brachytherapy for rGBM. Outcomes of interest were mOS, mPFS, OS, PFS, and adverse events (AEs). For individual clinical survival outcomes and common AEs, weighted-mean descriptive statistics were calculated as a summary measure using study sample size as the weight. The calculation formula is as follows: weighted-mean = Σwx/Σw (w is the sample size and x is the outcome).

RESULTS

This review included 29 studies with a total of 1202 rGBM patients, including 22 retrospective and 7 prospective studies. The results showed that from the time of brachytherapy, the mOS and mPFS were 6.8 to 24.4 months and 3.7 to 11.7 months. The OS of 6 months, 1 year, 18 months, 2 years, and 3 years after brachytherapy were 58.3 % to 85.2 % (weighted-mean 76.2 %), 26 % to 66 % (weighted-mean 41.9 %), 20 % to 37 % (weighted-mean 27.6 %), 11 % to 23 % (weighted-mean 14.8 %), and 8 % to 15 % (weighted-mean 12.1 %), respectively. The PFS of 6 months and 1 year after brachytherapy were 26.7 % to 86 % (weighted-mean 53.4 %) and 14 % to 81 % (weighted-mean 24.1 %). Most patients with rGBM will experience treatment failure again during the follow-up period, mainly local (10.7 % to 79.4 %) or marginal(3.6 % to 22.2 %) recurrence, followed by distant failure (6.7 % to 57.7 %). Although therapeutic AEs had not been uniformly reported, the overall toxicity rate was considered to be low. The common AEs reported included progressive neurologic deterioration, seizures, CSF leak, brain necrosis, hemorrhage, and infection/meningitis, with a weighted-mean incidence of 1.9 %, 2.4 %, 4.1 %, 5.4 %, 2.1 %, and 3.8 %, respectively.

CONCLUSIONS

The evidence summarized above, albeit mostly level III, suggests that brachytherapy has acceptable safety and good post-treatment clinical efficacy for selected patients with rGBM. Well-designed, high-quality, large-sample randomized controlled and prospective studies are needed to further validate these findings.

Interstitial Photodynamic Therapy of Glioblastomas: A Long-Term Follow-up Analysis of Survival and Volumetric MRI Data

BACKGROUND

The treatment of glioblastomas, the most common primary malignant brain tumors, with a devastating survival perspective, remains a major challenge in medicine. Among the recently explored therapeutic approaches, 5-aminolevulinic acid (5-ALA)-mediated interstitial photodynamic therapy (iPDT) has shown promising results.

METHODS

A total of 16 patients suffering from de novo glioblastomas and undergoing iPDT as their primary treatment were retrospectively analyzed regarding survival and the characteristic tissue regions discernible in the MRI data before treatment and during follow-up. These regions were segmented at different stages and were analyzed, especially regarding their relation to survival.

RESULTS

In comparison to the reference cohorts treated with other therapies, the iPDT cohort showed a significantly prolonged progression-free survival (PFS) and overall survival (OS). A total of 10 of 16 patients experienced prolonged OS (≥ 24 months). The dominant prognosis-affecting factor was the MGMT promoter methylation status (methylated: median PFS of 35.7 months and median OS of 43.9 months) (unmethylated: median PFS of 8.3 months and median OS of 15.0 months) (combined: median PFS of 16.4 months and median OS of 28.0 months). Several parameters with a known prognostic relevance to survival after standard treatment were not found to be relevant to this iPDT cohort, such as the necrosis-tumor ratio, tumor volume, and posttreatment contrast enhancement. After iPDT, a characteristic structure (iPDT remnant) appeared in the MRI data in the former tumor area.

CONCLUSIONS

In this study, iPDT showed its potential as a treatment option for glioblastomas, with a large fraction of patients having prolonged OS. Parameters of prognostic relevance could be derived from the patient characteristics and MRI data, but they may partially need to be interpreted differently compared to the standard of care.

Safety and patterns of survivorship in recurrent GBM following resection and surgically targeted radiation therapy: Results from a prospective trial

Background

Treatment of recurrent glioblastoma (GBM) remains problematic with survival after additional therapy typically less than 12 months. We prospectively evaluated whether outcomes might be improved with resection plus permanent implantation of a novel radiation device utilizing the gamma-emitting isotope Cs-131 embedded within bioresorbable collagen tiles.

Methods

Recurrent histologic GBM were treated in a single-arm trial. Following radiation, the surgical bed was lined with the tiles. Subsequent treatments were at the treating physician’s discretion.

Results

28 patients were treated (20 at first recurrence, range 1–3). Median age was 58 years, KPS was 80, female:male ratio was 10:18. Methylguanine methyltransferase (MGMT) was methylated in 11%, unmethylated in 18%, and unknown in 71%. Post implant, 17 patients (61%) received ≥1 course of systemic therapy. For all patients, Kaplan-Meier estimates of median time to local failure were 12.1 months, post-implant survival was 10.7 months for all patients and 15.1 months for patients who received systemic therapy; for all patients, median overall survival from diagnosis was 25.0 months (range 9.1–143.1). Sex, age, and number of prior progressions were not statistically significant. Local control was continuously maintained in 46% of patients. Two deaths within 30 days occurred, one from intracranial hemorrhage and one after persistent coma. Three symptomatic adverse events occurred: one wound infection requiring surgery and two late radiation brain injury, resolved non-surgically.

Conclusion

This pre-commercial trial demonstrated acceptable safety and favorable post-treatment local control and survival. The device has received FDA clearance for use in newly diagnosed malignant and all recurrent intracranial neoplasms.

Updates in intraoperative strategies for enhancing intra-axial brain tumor control

To ensure excellent postoperative clinical outcomes while preserving critical neurologic function, neurosurgeons who manage patients with intra-axial brain tumors can use intraoperative technologies and tools to achieve maximal safe resection. Neurosurgical oncology revolves around safe and optimal extent of resection, which further dictates subsequent treatment regimens and patient outcomes. Various methods can be adapted for treating both primary and secondary intra-axial brain lesions. We present a review of recent advances and published research centered on different innovative tools and techniques, including fluorescence-guided surgery, new methods of drug delivery, and minimally invasive procedural options.

Medical Device Advances in the Treatment of Glioblastoma

Despite decades of research and the growing emergence of new treatment modalities, Glioblastoma (GBM) frustratingly remains an incurable brain cancer with largely stagnant 5-year survival outcomes of around 5%. Historically, a significant challenge has been the effective delivery of anti-cancer treatment. This review aims to summarize key innovations in the field of medical devices, developed either to improve the delivery of existing treatments, for example that of chemo-radiotherapy, or provide novel treatments using devices, such as sonodynamic therapy, thermotherapy and electric field therapy. It will highlight current as well as emerging device technologies, non-invasive versus invasive approaches, and by doing so provide a detailed summary of evidence from clinical studies and trials undertaken to date. Potential limitations and current challenges are discussed whilst also highlighting the exciting potential of this developing field. It is hoped that this review will serve as a useful primer for clinicians, scientists, and engineers in the field, united by a shared goal to translate medical device innovations to help improve treatment outcomes for patients with this devastating disease.

Nomograms for prognostic risk assessment in glioblastoma multiforme: Applications and limitations

Glioblastoma multiforme (GBM) is the most common and aggressive form of brain cancer. Prognosis evaluation is of great significance in guiding individualized treatment and monitoring of GBM. By integrating different prognostic variables, nomograms simplify the statistical risk prediction model into numerical estimates for death or recurrence, and are hence widely applied in prognosis prediction. In the past two decades, the application of high-throughput profiling technology and the establishment of TCGA database and other public data deposits have provided opportunities to identify cancer-related molecules and prognostic biomarkers. As a result, both molecular features and clinical characteristics of cancer have been reported to be the key factors in nomogram model construction. This article comprehensively reviewed 35 studies of GBM nomograms, analyzed the present situation of GBM nomograms, and discussed the role and significance of nomograms in personalized risk assessment and clinical treatment decision-making. To facilitate the application of nomograms in the prognostic prediction of GBM patients, a website has been established for the online access of nomograms based on the studies of this review, which is called Consensus Nomogram Spectrum for Glioblastoma (CNSgbm) and is accessible through https://bioinfo.henu.edu.cn/nom/NomList.jsp.

Advances in local therapy for glioblastoma - taking the fight to the tumour

Despite advances in neurosurgery, chemotherapy and radiotherapy, glioblastoma remains one of the most treatment-resistant CNS malignancies, and the tumour inevitably recurs. The majority of recurrences appear in or near the resection cavity, usually within the area that received the highest dose of radiation. Many new therapies focus on combatting these local recurrences by implementing treatments directly in or near the tumour bed. In this Review, we discuss the latest developments in local therapy for glioblastoma, focusing on recent preclinical and clinical trials. The approaches that we discuss include novel intraoperative techniques, various treatments of the surgical cavity, stereotactic injections directly into the tumour, and new developments in convection-enhanced delivery and intra-arterial treatments.

A Multiparametric MRI-Based Radiomics Nomogram for Preoperative Prediction of Survival Stratification in Glioblastoma Patients With Standard Treatment

OBJECTIVE

To construct and validate a radiomics nomogram for preoperative prediction of survival stratification in glioblastoma (GBM) patients with standard treatment according to radiomics features extracted from multiparameter magnetic resonance imaging (MRI), which could facilitate clinical decision-making.

METHODS

A total of 125 eligible GBM patients (53 in the short and 72 in the long survival group, separated by an overall survival of 12 months) were randomly divided into a training cohort (n = 87) and a validation cohort (n = 38). Radiomics features were extracted from the MRI of each patient. The T-test and the least absolute shrinkage and selection operator algorithm (LASSO) were used for feature selection. Next, three feature classifier models were established based on the selected features and evaluated by the area under curve (AUC). A radiomics score (Radscore) was then constructed by these features for each patient. Combined with clinical features, a radiomics nomogram was constructed with independent risk factors selected by the logistic regression model. The performance of the nomogram was assessed by AUC, calibration, discrimination, and clinical usefulness.

RESULTS

There were 5,216 radiomics features extracted from each patient, and 5,060 of them were stable features judged by the intraclass correlation coefficients (ICCs). 21 features were included in the construction of the radiomics score. Of three feature classifier models, support vector machines (SVM) had the best classification effect. The radiomics nomogram was constructed in the training cohort and exhibited promising calibration and discrimination with AUCs of 0.877 and 0.919 in the training and validation cohorts, respectively. The favorable decision curve analysis (DCA) indicated the clinical usefulness of the radiomics nomogram.

CONCLUSIONS

The presented radiomics nomogram, as a non-invasive tool, achieved satisfactory preoperative prediction of the individualized survival stratification of GBM patients.

Utility of Administrative Databases and Big Data on Understanding Glioma Treatment—A Systematic Review

Background Gliomas are a heterogeneous group of tumors where large multicenter clinical and genetic studies have become increasingly popular in their understanding. We reviewed and analyzed the findings from large databases in gliomas, seeking to understand clinically relevant information.

Methods A systematic review was performed for gliomas studied using large administrative databases up to January 2020 (e.g., National Inpatient Sample [NIS], National Surgical Quality Improvement Program [NSQIP], and Surveillance, Epidemiology, and End Results Program [SEER], National Cancer Database [NCDB], and others).

Results Out of 390 screened studies, 122 were analyzed. Studies included a wide range of gliomas including low- and high-grade gliomas. The SEER database (n = 83) was the most used database followed by NCDB (n = 28). The most common pathologies included glioblastoma multiforme (GBM) (n = 67), with the next category including mixes of grades II to IV glioma (n = 31). Common study themes involved evaluation of descriptive epidemiological trends, prognostic factors, comparison of different pathologies, and evaluation of outcome trends over time. Persistent health care disparities in patient outcomes were frequently seen depending on race, marital status, insurance status, hospital volume, and location, which did not change over time. Most studies showed improvement in survival because of advances in surgical and adjuvant treatments.

Conclusions This study helps summarize the use of clinical administrative databases in gliomas research, informing on socioeconomic issues, surgical outcomes, and adjuvant treatments over time on a national level. Large databases allow for some study questions that would not be possible with single institution data; however, limitations remain in data curation, analysis, and reporting methods.

Dosimetric Impacts of Source Migration, Radioisotope Type, and Decay with Permanent Implantable Collagen Tile Brachytherapy for Brain Tumors

Introduction: Brachytherapy using permanently implantable collagen tiles containing cesium-131 (Cs-131) is indicated for treatment of malignant intracranial neoplasms. We quantified Cs-131 source migration and modeled the resulting dosimetric impact for Cs-131, iodine-125 (I-125), and palladium-103 (Pd-103). Methods and Materials: This was a retrospective analysis of a subgroup of patients enrolled in a prospective, single-center, nonrandomized, clinical trial (NCT03088579) of Cs-131 collagen tile brachytherapy. Postimplant Cs-131 plans and hypothetical I-125 and Pd-103 calculations were compared for 20 glioblastoma patients for a set seed geometry. Dosimetric impact of decay and seed migration was calculated for 2 hypothetical scenarios: Scenario 1, assuming seed positions on a given image set were unchanged until acquisition of the subsequent set; Scenario 2, assuming any change in seed positions occurred the day following acquisition of the prior images. Seed migration over time was quantified for a subset of 7 patients who underwent subsequent image-guided radiotherapy. Results: Mean seed migration was 1.7 mm (range: 0.7-3.1); maximum seed migration was 4.3 mm. Mean dose to the 60 Gy volume differed by 0.4 Gy (0.6%, range 0.1-1.0) and 0.9 Gy (1.5%, range 0.2-1.7) for Cs-131, 1.2 Gy (2.0%, range 0.1-2.1) and 1.6 Gy (2.6%, range 1.2-2.6) for I-125, and 0.8 Gy (1.3%, range 0.2-1.5) and 1.4 Gy (2.3%, range 0.3-1.9) for Pd-103, for Scenarios 1 and 2, respectively, compared with the postimplant plan. For a set seed geometry mean implant dose was higher for Pd-103 (1.3 times) and I-125 (1.1 times) versus Cs-131. Dose fall-off was steepest for Pd-103: gradient index 1.88 versus 2.23 (I-125) and 2.40 (Cs-131). Conclusions: Dose differences due to source migration were relatively small, suggesting robust prevention of seed migration from Cs-131-containing collagen tiles. Intratarget heterogeneity was greater with Pd-103 and I-125 than Cs-131. Dose fall-off was fastest with Pd-103 followed by I-125 and then Cs-131.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.

The Nomogram Model Predicting Overall Survival and Guiding Clinical Decision in Patients With Glioblastoma Based on the SEER Database

Background: Patients with glioblastoma have a poor prognosis. We want to develop and validate nomograms for predicting overall survival in patients with glioblastoma. Methods: Data of patients with glioblastoma diagnosed pathologically in the SEER database from 2007 to 2016 were collected by SEER*Stat software. After eliminating invalid and missing clinical information, 3,635 patients (total group) were finally identified and randomly divided into the training group (2,183 cases) and the verification group (1,452 cases). Cox proportional risk regression model was used in the training group, the verification group and the total group to analyze the prognostic factors of patients in the training group, and then the nomogram was constructed. C-indexes and calibration curves were used to evaluate the predictive value of nomogram by internal (training group data) and external validation (verification group data). Results: Cox proportional risk regression model in the training group showed that age, year of diagnosis, laterality, radiation, chemotherapy were all influential factors for prognosis of patients with glioblastoma (P < 0.05) and were all used to construct nomogram as well. The internal and external validation results of nomogram showed that the C-index of the training group was 0.729 [95% CI was (0.715, 0.743)], and the verification group was 0.734 [95% CI was (0.718, 0.750)]. The calibration curves of both groups showed good consistency. Conclusions: The proposed nomogram resulted in accurate prognostic prediction for patients with glioblastoma.

Blood-Brain Barrier, Blood-Brain Tumor Barrier, and Fluorescence-Guided Neurosurgical Oncology: Delivering Optical Labels to Brain Tumors

Recent advances in maximum safe glioma resection have included the introduction of a host of visualization techniques to complement intraoperative white-light imaging of tumors. However, barriers to the effective use of these techniques within the central nervous system remain. In the healthy brain, the blood-brain barrier ensures the stability of the sensitive internal environment of the brain by protecting the active functions of the central nervous system and preventing the invasion of microorganisms and toxins. Brain tumors, however, often cause degradation and dysfunction of this barrier, resulting in a heterogeneous increase in vascular permeability throughout the tumor mass and outside it. Thus, the characteristics of both the blood-brain and blood-brain tumor barriers hinder the vascular delivery of a variety of therapeutic substances to brain tumors. Recent developments in fluorescent visualization of brain tumors offer improvements in the extent of maximal safe resection, but many of these fluorescent agents must reach the tumor via the vasculature. As a result, these fluorescence-guided resection techniques are often limited by the extent of vascular permeability in tumor regions and by the failure to stain the full volume of tumor tissue. In this review, we describe the structure and function of both the blood-brain and blood-brain tumor barriers in the context of the current state of fluorescence-guided imaging of brain tumors. We discuss features of currently used techniques for fluorescence-guided brain tumor resection, with an emphasis on their interactions with the blood-brain and blood-tumor barriers. Finally, we discuss a selection of novel preclinical techniques that have the potential to enhance the delivery of therapeutics to brain tumors in spite of the barrier properties of the brain.

Evolving Strategies to Potentially Further Optimize Surgical Interventions in Brain Cancer

PURPOSE OF REVIEW

Provide an overview, the indications for use, and a synopsis of current literature regarding two evolving neurosurgical interventions-GammaTile therapy (GTT) and laser interstitial thermal therapy (LITT).

RECENT FINDINGS

GTT delivers immediate, uniform, high-dose radiation with avoidance of direct brain-to-seed contact. Innate properties of the novel carrier system and cesium-131 source may explain lower observed rate of radiation-induced necrosis (RIN) and support use in larger and previously irradiated lesions. LITT delivers focal laser energy to cause heat-generated necrosis. Case series suggest use in difficult-to-access lesions and treatment of RIN. Collaboration among subspecialties and remaining up-to-date on evolving technology is critical in developing individualized treatment plans for patients with brain cancer. While patients should be thoroughly counseled that these interventions are not standard of care, in optimal clinical scenarios, GTT and LITT could extend quantity and quality of life for patients with few remaining options. Prospective studies are needed to establish specific treatment parameters.