Comparative dosimetric study of radiotherapy in high-grade gliomas based on the guidelines of EORTC and NRG-2019 target delineation

Purpose

Radiotherapy is one of the most important treatments for high-grade glioma (HGG), but the best way to delineate the target areas for radiotherapy remains controversial, so our aim was to compare the dosimetric differences in radiation treatment plans generated based on the European Organization for Research and Treatment of Cancer (EORTC) and National Research Group (NRG) consensus to provide evidence for optimal target delineation for HGG.

Methods

We prospectively enrolled 13 patients with a confirmed HGG from our hospital and assessed dosimetric differences in radiotherapy treatment plans generated according to the EORTC and NRG-2019 guidelines. For each patient, two treatment plans were generated. Dosimetric parameters were compared by dose-volume histograms for each plan.

Results

The median volume for planning target volume (PTV) of EORTC plans, PTV1 of NRG-2019 plans, and PTV2 of NRG-2019 plans were 336.6 cm³ (range, 161.1-511.5 cm³), 365.3 cm³ (range, 123.4-535.0 cm³), and 263.2 cm³ (range, 116.8-497.7 cm³), respectively. Both treatment plans were found to have similar efficiency and evaluated as acceptable for patient treatment. Both treatment plans showed well conformal index and homogeneity index and were not statistically significantly different (P = 0.397 and P = 0.427, respectively). There was no significant difference in the volume percent of brain irradiated to 30, 46, and 60 Gy according to different target delineations (P = 0.397, P = 0.590, and P = 0.739, respectively). These two plans also showed no significant differences in the doses to the brain stem, optic chiasm, left and right optic nerves, left and right lens, left and right eyes, pituitary, and left and right temporal lobes (P = 0.858, P = 0.858, P = 0.701 and P = 0.794, P = 0.701 and P = 0.427, P = 0.489 and P = 0.898, P = 0.626, and P = 0.942 and P = 0.161, respectively).

Conclusion

The NRG-2019 project did not increase the dose of organs at risk (OARs) radiation. This is a significant finding that further lays the groundwork for the application of the NRG-2019 consensus in the treatment of patients with HGGs.

Clinical trial registration

The effect of radiotherapy target area and glial fibrillary acidic protein (GFAP) on the prognosis of high-grade glioma and its mechanism, number ChiCTR2100046667. Registered 26 May 2021.

Diffuse Intrinsic Pontine Glioma: Molecular Landscape, Evolving Treatment Strategies and Emerging Clinical Trials

Diffuse intrinsic pontine glioma (DIPG) is a type of intrinsic brainstem glial tumor that occurs primarily in the pediatric population. DIPG is initially diagnosed based on clinical symptoms and the characteristic location on imaging. Histologically, these tumors are characterized by a heterogenous population of cells with multiple genetic mutations and high infiltrative capacity. The most common mutation seen in this group is a lysine to methionine point mutation seen at position 27 (K27M) within histone 3 (H3). Tumors with the H3 K27M mutation, are considered grade 4 and are now categorized within the H3 K27-altered diffuse midline glioma category by World Health Organization classification. Due to its critical location and aggressive nature, DIPG is resistant to the most eradicative treatment and is universally fatal; however, modern advances in the surgical techniques resulting in safe biopsy of the lesion have significantly improved our understanding of this disease at the molecular level. Genomic analysis has shown several mutations that play a role in the pathophysiology of the disease and can be targeted therapeutically. In this review, we will elaborate on DIPG from general aspects and the evolving molecular landscape. We will also review innovative therapeutic options that have been trialed along with new promising treatments on the horizon.

Cancer Predisposition Syndromes Associated With Pediatric High-Grade Gliomas

Pediatric High-Grade Gliomas (pHGG) are among the deadliest childhood brain tumors and can be associated with an underlying cancer predisposing syndrome. The thorough understanding of these syndromes can aid the clinician in their prompt recognition, leading to an informed genetic counseling for families and to a wider understanding of a specific genetic landscape of the tumor for target therapies. In this review, we summarize the main pHGG-associated cancer predisposing conditions, providing a guide for suspecting these syndromes and referring for genetic counseling.

Feasibility of Treating High Grade Gliomas in Children with Tumor-Treating Fields: A Case Series

Children diagnosed with high grade gliomas (HGG) have dismal prognoses and treatment options remain limited. Tumor treating fields (TTFields) in combination with temozolomide (TMZ) is approved for the treatment of newly diagnosed and recurrent glioblastoma (GBM) in adult patients. However, clinical experience with TTFields in the pediatric HGG population is lacking.

This retrospective review of four clinical cases was undertaken to evaluate the feasibility of treating children diagnosed with HGG off-label with TTFields. Patients were evaluated for device compliance, safety, and outcome. Treatment with TTFields was delivered via four transducer arrays placed on the shaved scalp, which were connected to a portable device generating 200 kHz alternating electric fields.

One female and three male patients (ages 4-16 years) with heavily pretreated HGG were treated with TTFields off-label from March 2015 to December 2016. In three of these cases, TTFields were administered in combination with TMZ. Across all four patient cases, average wear compliance rates ranged between 53% and 92%. No device-related toxicities were reported during treatment with TTFields delivered for up to four months. All patients eventually died of the disease.

TTFields was well tolerated in our limited cohort of patients. Compliance times were similar to what has been reported in adults without significant toxicity. Further studies of the efficacy and safety of TTFields in children with HGG are underway in a clinical trial setting.

Prognostic value of modified Glasgow prognostic score in recurrent high-grade glial tumors treated with systemic treatment

OBJECTIVES

Malignant high-grade gliomas are the most common and aggressive type of primary brain tumor. We aimed to evaluate the prognostic value of modified Glasgow Prognostic Score (mGPS), which is combination of C-reactive protein (CRP) and albumin, in recurrent high-grade glioma patients treated with systemic treatment.

PATIENTS AND METHODS

Data of 85 patients with recurrent high-grade glioma who received systemic treatment and followed in our clinic between 2012 and 2018 was retrospectively collected and analyzed. Patients were grouped according to mGPS criteria: mGPS-0: CRP < 10 mg/L and albumin >3.5 g/dL; mGPS-1: CRP < 10 mg/L and albumin <3.5 g/dL or CRP > 10 mg/L and albumin >3.5 g/dL; and mGPS-2: CRP > 10 mg/L and albumin <3.5 mg/L. We investigated the prognostic role of mGPS groups, mutations and survival outcomes.

RESULTS

There were 42 (49.4 %), 25 (29.6 %), and 18 (21 %) patients in mGPS-0, mGPS-1, and mGPS-2 groups, respectively. Median follow-up duration was 10 months (1-70 months). Median OS was 8.1 months. According to mGPS-0, -1 and -2; median OS was 13.8 months, 7.3 months and 3.6 months respectively (p = 0.003). mGPS, ATRX and IDH-1 mutation status, and ECOG PS were found to be independent prognostic factors for OS.

CONCLUSION

In our study, mGPS was found to be an independent prognostic factor in patients with recurrent high-grade gliomas. If validated, mGPS can be used as an objective, easily calculated, cheap, and readily available prognostic model in routine practice.

Deubiquitinase USP9X deubiquitinates β-catenin and promotes high grade glioma cell growth

β-catenin is a crucial signal transduction molecule in the Wnt/β-catenin signal pathway, and increased β-catenin expression has consistently been found in high grade gliomas. However, the mechanisms responsible for β-catenin overexpression have remained elusive.

Here we show that the deubiquitinase USP9X stabilizes β-catenin and thereby promotes high grade glioma cell growth. USP9X binds β-catenin and removes the Lys 48-linked polyubiquitin chains that normally mark β-catenin for proteasomal degradation. Increased USP9X expression correlates with increased β-catenin protein in high grade glioma tissues. Moreover, patients with high grade glioma overexpressing USP9X have a poor prognosis. Knockdown of USP9X suppresses cell proliferation, inhibits G1/S phase conversion, and induces apoptosis in U251 and A172 cells. Interestingly, c-Myc and cyclinD1, which are important downstream target genes in the Wnt/β-catenin signal pathway, also show decreased expression in cells with siRNA-mediated down-regulation of USP9X. Down-regulation of USP9X also consistently inhibits the tumorigenicity of primary glioma cells in vivo.

In summary, these results indicate that USP9X stabilizes β-catenin and activates Wnt/β-catenin signal pathway to promote glioma cell proliferation and survival. USP9X could also potentially be a novel therapeutic target for high grade gliomas.

Differentiation between vasogenic edema and infiltrative tumor in patients with high-grade gliomas using texture patch-based analysis

BACKGROUND

High-grade gliomas (HGGs) induce both vasogenic edema and extensive infiltration of tumor cells, both of which present with similar appearance on conventional MRI. Using current radiological criteria, differentiation between these tumoral and nontumoral areas within the nonenhancing lesion area remains challenging.

PURPOSE

To use radiomics patch-based analysis, based on conventional MRI, for the classification of the nonenhancing lesion area in patients with HGG into tumoral and nontumoral components.

STUDY TYPE

Prospective.

SUBJECTS

In all, 179 MRI scans were obtained from 102 patients: 67 patients with HGG and 35 patients with brain metastases. A subgroup of 15 patients with HGG were scanned before and following administration of bevacizumab.

FIELD STRENGTH/SEQUENCE

Pre and postcontrast agent T1 -weighted-imaging (WI), T2 WI, FLAIR, diffusion-tensor-imaging (DTI), and dynamic-contrast-enhanced (DCE)-MRI at 3T.

ASSESSMENT

A total of 225 histograms and gray-level-co-occurrence matrix-based features were extracted from the nonenhancing lesion area. Tumoral volumes of interest (VOIs) were defined at the peritumoral area in patients with HGG; nontumoral VOIs were defined in patients with brain metastasis. Twenty machine-learning algorithms including support-vector-machine (SVM), k-nearest neighbor, decision-trees, and ensemble classifiers were tested. The best classifier was trained on the entire labeled data, and was used to classify the entire data.

STATISTICAL TESTS

Dimensional reduction was performed on the 225 features using principal component analysis. Classification results were evaluated based on the sensitivity, specificity, and accuracy of each of the 20 classifiers, first based on a training and testing dataset (80% of the labeled data) in a 5-fold manner, and next by applying the best classifier to the validation data (the remaining 20% of the labeled data). Results were additionally evaluated by assessing differences in dynamic-contrast-enhanced plasma-volume (vp ) and volume-transfer-constant (ktrans ) values between the two components using Mann-Whitney U-test/t-test.

RESULTS

The best classification into tumoral and nontumoral lesion components was obtained using a linear SVM classifier, with average accuracy of 87%, sensitivity 86%, and specificity of 89% (for the training and testing data). Significantly higher vp and ktrans values (P < 0.0001) were detected in the tumoral compared to the nontumoral component. Preliminary classification results in a subgroup of patients treated with bevacizumab demonstrated a reduction mainly in the nontumoral component following administration of bevacizumab, enabling early assessment of disease progression in some patients.

DATA CONCLUSION

A radiomics patch-based analysis enables classification of the nonenhancing lesion area in patients with HGG. Preliminary results were promising and the proposed method has the potential to assist in clinical decision-making and to improve therapy response assessment in patients with HGG.

LEVEL OF EVIDENCE

1 Technical Efficacy Stage 4 J. Magn. Reson. Imaging 2018.

Experiencing brain cancer: what physicians should know about patients

During the last 20 years, numerous studies have highlighted the need to consider Quality of Life (QoL) issues in the treatment of brain cancer. However, gaps in scientific knowledge are still present as we have poor data surrounding the whole experience in patients and regarding their needs.

The present study was aimed at evaluating QoL in brain cancer patients and correlated aspects. In particular, we aimed to assess QoL, mood state, and emotional issues in order to describe the patients’ experience to find out the critical aspects involved.

Potential role of fractional anisotropy derived from diffusion tensor imaging in differentiating high-grade gliomas from low-grade gliomas: a meta-analysis

BACKGROUND AND PURPOSE

It is crucial to accurately differentiate high-grade gliomas (HGGs) from low-grade gliomas (LGGs) preoperatively, as treatment strategies vary. So we performed a meta-analysis to assess the sensitivity and specificity of fractional anisotropy (FA) value derived from diffusion tensor imaging (DTI) in differentiating HGGs from LGGs.

MATERIALS AND METHODS

Between January 2005 and June 2014, relevant articles were searched from the Embase and Medline databases for analysis. Statistical analyses were performed using Meta-Disc 1.4.

RESULTS

A total of 221 patients included in the FA analysis: 127 with HGGs and 94 LGGs. The pooled sensitivity, specificity and diagnostic odds ratio (DOR) for differentiating HGGs from LGGs were 93% (95% CI 0.87-0.97), 85% (95% CI 0.76-0.92), and 55.41 (95% CI 16.77-183.07), respectively. And computation of heterogeneity metrics revealed an acceptable level of the between-study heterogeneity of DOR (I(2)=30.9%).

CONCLUSIONS

The results of our meta-analysis present that the FA derived from DTI act as a useful diagnostic marker could be used in distinguishing the HGGs from LGGs in the preoperative and the clinical application values are to be confirmed by further larger case-control studies.

Meta-analysis of peritumoural rCBV values derived from dynamic susceptibility contrast imaging in differentiating high-grade gliomas from intracranial metastases

BACKGROUND AND PURPOSE

In the preoperative period, it is very important to accurately differentiate high-grade gliomas from intracranial metastases, as treatment strategies vary. Hence we performed a meta-analysis to evaluate the sensitivity and specificity of peritumoural relative cerebral blood volume (rCBV) values derived from dynamic susceptibility contrast imaging (DSCI) in differentiating high-grade gliomas from intracranial metastases.

MATERIALS AND METHODS

Between 2004 and June 2014, relevant studies were searched from the databases of Medline and Embase for analysis. A total of 3 eligible studies were included in this analysis. Statistical analysis was performed with Meta-Disc 1.4.

RESULTS

A total of 136 patients included in the rCBV analysis: 79 with high-grade glioma and 57 with metastasis. The pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (-LR) and diagnostic odds ratio (DOR) for differentiating high-grade glioma from metastasis were 82% (95% CI 0.72-0.90), 96% (95% CI 0.88-1.00), 18.04 (95% CI 5.41-60.15), 0.19 (95% CI 0.12-0.31), and 90.20 (95% CI 23.10-352.27), respectively. The value of Cochran's Q of DOR was 0.78 (P = 0.6774), and I2 was 0.0%, revealing that no statistically significant between-study heterogeneity was found.

CONCLUSIONS

The results of this present study clearly present that the peritumoural rCBV values derived from DSCI could be used in distinguishing high-grade gliomas from intracranial metastases in the preoperative.

Nimotuzumab as a radiosensitizing agent in the treatment of high grade glioma: challenges and opportunities

Nimotuzumab is a humanized monoclonal antibody that binds specifically to human epidermal growth factor receptor, blocking receptor activation. Evidence of its radiosensitizing capacity has been widely evaluated. This article integrates published research findings regarding the role of nimotuzumab in the treatment of high grade glioma in combination with radiotherapy or radiochemotherapy in adult and pediatric populations. First, the mechanisms of action of nimotuzumab and its current applications in clinical trials containing both radiation and chemoradiation therapies are reviewed. Second, a comprehensive explanation of potential mechanisms driving radiosensitization by nimotuzumab in experimental settings is given. Finally, future directions of epidermal growth factor receptor targeting with nimotuzumab in combination with radiation containing regimens, based on its favorable toxicity profile, are proposed. It is hoped that this review may provide further insight into the rational design of new approaches employing nimotuzumab as a useful alternative for the therapeutic management of high grade glioma.