Abstract Background Quantifying tumor growth and treatment response noninvasively poses a challenge to all experimental tumor models. The aim of our study was, to assess the value of quantitative and ...visual examination and radiomic feature analysis of high-resolution MR images of heterotopic glioblastoma xenografts in mice to determine tumor cell proliferation (TCP). Methods Human glioblastoma cells were injected subcutaneously into both flanks of immunodeficient mice and followed up on a 3 T MR scanner. Volumes and signal intensities were calculated. Visual assessment of the internal tumor structure was based on a scoring system. Radiomic feature analysis was performed using MaZda software. The results were correlated with histopathology and immunochemistry. Results 21 tumors in 14 animals were analyzed. The volumes of xenografts with high TCP (H-TCP) increased, whereas those with low TCP (L-TCP) or no TCP (N-TCP) continued to decrease over time ( p < 0.05). A low intensity rim (rim sign) on unenhanced T1-weighted images provided the highest diagnostic accuracy at visual analysis for assessing H-TCP ( p < 0.05). Applying radiomic feature analysis, wavelet transform parameters were best for distinguishing between H-TCP and L-TCP / N-TCP ( p < 0.05). Conclusion Visual and radiomic feature analysis of the internal structure of heterotopically implanted glioblastomas provide reproducible and quantifiable results to predict the success of transplantation.
Pineal region tumors commonly present with non-communicating hydrocephalus. These heterogeneous histological entities require different therapeutic regimens. We evaluated our surgical experience ...concerning procurance of a histological diagnosis, management of hydrocephalus, and choice of antitumoral treatment. We analyzed the efficacy of neuroendoscopic biopsy and endoscopic third ventriculocisternostomy (ETV) in patients with pineal region tumors between 2006 and 2019 in a single-center retrospective cross-sectional study with regard to diagnostic yield, hydrocephalus treatment, as well as impact on further antitumoral management. Out of 28 identified patients, 23 patients presented with untreated hydrocephalus and 25 without histological diagnosis. One patient underwent open biopsy, and 24 received a neuroendoscopic biopsy with concomitant hydrocephalus treatment if necessary. Eighteen primary ETVs, 2 secondary ETVs, and 2 ventriculoperitoneal shunts (VPSs) were performed. Endoscopic biopsy had a diagnostic yield of 95.8% (23/24) and complication rates of 12.5% (transient) and 4.2% (permanent), respectively. ETV for hydrocephalus management was successful in 89.5% (17/19) with a median follow-up of more than 3 years. Following histological diagnosis, 8 patients (28.6%) underwent primary resection of their tumor. Another 9 patients underwent later-stage resection after either adjuvant treatment (
n
= 5) or for progressive disease during observation (
n
= 4). Eventually, 20 patients received adjuvant treatment and 7 were observed after primary management. One patient was lost to follow-up. Heterogeneity of pineal region tumor requires histological confirmation. Primary biopsy of pineal lesions should precede surgical resection since less than a third of patients needed primary surgical resection according to the German pediatric brain tumor protocols. Interdisciplinary decision making upfront any treatment is warranted in order to adequately guide treatment.
According to the WHO classification, ependymal tumors are classified as subependymomas, myxopapillary ependymomas, classic ependymomas, anaplastic ependymomas, and
RELA
-fusion-positive ependymomas ...(RELA-EPN). Among classic ependymomas, the WHO defines rare histological variants, i.e., the clear cell, papillary, and tanycytic ependymoma. In parallel, global DNA methylation patterns distinguish nine molecular groups, some of which tightly overlap with histopathological subgroups. However, the match of the aforementioned histological variants to DNA methylation classes remains unclear. We analyzed histomorphology, clinical parameters, and global DNA methylation of tumors with the initial histological diagnoses of tanycytic (
n
= 12), clear cell (
n
= 14), or papillary ependymoma (
n
= 19). Forty percent of these tumors did not match to the epigenetic profile of ependymomas, using a previously published DNA methylation-based classifier for brain tumors. Instead, they were classified as low-grade glioma (
n
= 3), plexus tumor (
n
= 2), CNS high-grade neuroepithelial tumor with MN1 alteration (
n
= 2), papillary tumor of the pineal region (
n
= 2), neurocytoma (
n
= 1), or did not match to any known brain tumor methylation class (
n
= 8). Overall, integrated diagnosis had to be changed in 35.6% of cases as compared to the initial diagnosis. Among the tumors molecularly classified as ependymoma (27/45 cases), tanycytic ependymomas were mostly located in the spine (5/7 cases) and matched to spinal or myxopapillary ependymoma. 6/8 clear cell ependymomas were found supratentorially and fell into the methylation class of RELA-EPN. Papillary ependymomas with a positive ependymoma match (12/19 cases) showed either a “papillary” (
n
= 5), a “trabecular” (
n
= 1), or a “pseudo-papillary” (
n
= 6) growth pattern. The papillary growth pattern was strongly associated with the methylation class B of posterior fossa ependymoma (PFB, 5/5 cases) and tumors displayed DNA methylation sites that were significantly different when compared to PFB ependymomas without papillary growth. Tumors with pseudo-papillary histology matched to the methylation class of myxopapillary ependymoma (4/6 cases), whereas the trabecular case was anatomically and molecularly a spinal ependymoma. Our results show that the diagnosis of histological ependymoma variants is challenging and epigenetic profiles may improve diagnostic accuracy of these cases. Whereas clear cell and papillary ependymomas display correlations between localization, histology, and methylation, tanycytic ependymoma does not represent a molecularly distinct subgroup.
The large diversity of central nervous system (CNS) tumor types in children and adolescents results in disparate patient outcomes and renders accurate diagnosis challenging. In this study, we ...prospectively integrated DNA methylation profiling and targeted gene panel sequencing with blinded neuropathological reference diagnostics for a population-based cohort of more than 1,200 newly diagnosed pediatric patients with CNS tumors, to assess their utility in routine neuropathology. We show that the multi-omic integration increased diagnostic accuracy in a substantial proportion of patients through annotation to a refining DNA methylation class (50%), detection of diagnostic or therapeutically relevant genetic alterations (47%) or identification of cancer predisposition syndromes (10%). Discrepant results by neuropathological WHO-based and DNA methylation-based classification (30%) were enriched in histological high-grade gliomas, implicating relevance for current clinical patient management in 5% of all patients. Follow-up (median 2.5 years) suggests improved survival for patients with histological high-grade gliomas displaying lower-grade molecular profiles. These results provide preliminary evidence of the utility of integrating multi-omics in neuropathology for pediatric neuro-oncology.
The HIT-2000-BIS4 trial aimed to avoid highly detrimental craniospinal irradiation (CSI) in children < 4 years of age with nonmetastatic medulloblastoma by systemic chemotherapy, intraventricular ...methotrexate, and risk-adapted local radiotherapy.
From 2001-2011, 87 patients received systemic chemotherapy and intraventricular methotrexate. Until 2006, CSI was reserved for nonresponse or progression. After 2006, local radiotherapy was introduced for nonresponders or patients with classic medulloblastoma (CMB) or large-cell/anaplastic medulloblastoma (LCA). DNA methylation profiles of infantile sonic hedgehog-activated medulloblastoma (SHH-INF) were subdivided into iSHH-I and iSHH-II subtypes in the HIT-2000-BIS4 cohort and a validation cohort (n = 71) from the HIT group and Russia.
Five years after diagnosis, patients with desmoplastic medulloblastoma (DMB) or medulloblastoma with extensive nodularity (MBEN; n = 42) had 93% progression-free survival (5y-PFS), 100% overall survival (5y-OS), and 93% CSI-free (5y-CSI-free) survival. Patients with CMB/LCA (n = 45) had 37% 5y-PFS, 62% 5y-OS, and 39% 5y-CSI-free survival. Local radiotherapy did not improve survival in patients with CMB/LCA. All DMB/MBEN assessed by DNA methylation profiling belonged to the SHH-INF subgroup. Group 3 patients (5y-PFS, 36%; n = 14) relapsed more frequently than the SHH-INF group (5y-PFS, 93%; n = 28) or group 4 patients (5y-PFS, 83%; n = 6;
< .001). SHH-INF split into iSHH-I and iSHH-II subtypes in HIT-2000-BIS4 and the validation cohort, without prognostic impact (5y-PFS: iSHH-I, 73%,
iSHH-II, 83%;
= .25; n = 99). Intelligence quotient (IQ) was significantly lower in patients after CSI (mean IQ, 90 no radiotherapy,
74 CSI;
= .012).
Systemic chemotherapy and intraventricular methotrexate led to favorable survival in both iSHH subtypes of SHH-activated DMB/MBEN with acceptable neurotoxicity. Survival in patients with non-wingless (WNT)/non-SHH disease with CMB/LCA was not improved by local radiotherapy. Patients with group 4 disease had more favorable survival rates than those with group 3 medulloblastoma.
Background
Awake surgery to preserve language function in young children is challenging, therefore reliable non-invasive work-up of language functional anatomy is needed to preserve language function ...at any cost. Furthermore, there are obvious limitations of an awake craniotomy with direct stimulation on a child.
Case report
A 6-year-old boy with a low-grade glioma of the left temporal lobe suffering from epileptic seizures underwent surgery, guided by preoperative transcranial magnetic stimulation (TMS) language mapping and consecutive DTI fiber tracking.
Discussion and conclusion
We report successful surgery of a language eloquent brain tumor in a young child based on TMS mapping and DTI fiber tracking alone. Surgical treatment of left-sided perisylvian tumors in children is discussed.
Background
Although cavitating ultrasonic aspirators are commonly used in neurosurgical procedures, the suitability of ultrasonic aspirator-derived tumor material for diagnostic procedures is still ...controversial. Here, we explore the feasibility of using ultrasonic aspirator-resected tumor tissue to classify otherwise discarded sample material by fast DNA methylation-based analysis using low pass nanopore whole genome sequencing.
Methods
Ultrasonic aspirator-derived specimens from pediatric patients undergoing brain tumor resection were subjected to low-pass nanopore whole genome sequencing. DNA methylation-based classification using a neural network classifier and copy number variation analysis were performed. Tumor purity was estimated from copy number profiles. Results were compared to microarray (EPIC)-based routine neuropathological histomorphological and molecular evaluation.
Results
19 samples with confirmed neuropathological diagnosis were evaluated. All samples were successfully sequenced and passed quality control for further analysis. DNA and sequencing characteristics from ultrasonic aspirator-derived specimens were comparable to routinely processed tumor tissue. Classification of both methods was concordant regarding methylation class in 17/19 (89%) cases. Application of a platform-specific threshold for nanopore-based classification ensured a specificity of 100%, whereas sensitivity was 79%. Copy number variation profiles were generated for all cases and matched EPIC results in 18/19 (95%) samples, even allowing the identification of diagnostically or therapeutically relevant genomic alterations.
Conclusion
Methylation-based classification of pediatric CNS tumors based on ultrasonic aspirator-reduced and otherwise discarded tissue is feasible using time- and cost-efficient nanopore sequencing.
Abstract Pediatric low-grade gliomas (pLGG) are the most common brain tumors in children and are associated with significant morbidity. Therefore, there is an urgent need for novel therapeutic ...strategies. While some studies have described pLGG’s tumor microenvironment (TME) from bulk RNAseq and scRNAseq, little is known about the spatial architecture of pLGG and its association with clinico-molecular features. Our study utilized imaging mass cytometry and a panel of 35 metal-labelled antibodies to unravel the spatial organization of key TME cell populations in 120 primary pLGG samples from the LOGGIC Core BioClinical DataBank. Cellular neighborhood analysis was performed to map the spatial organization of pLGG TME. Several clinic-molecular features (entity, tumor location, genetic driver alteration, disease progression status, age and sex) were used to measure their putative association with the enrichment of key cell populations and cellular structures to identify diagnosis and prognosis markers. Here, we identified a predominant presence of myeloid cells in the TME, particularly notable in optic pathway tumors, which exhibited unique immune profiles. Optic pathway tumors demonstrated elevated immune subsets, delineating distinct architectural features in the TME of this brain region. Spatial analysis defined cellular neighborhoods and specific interactions thereof, including myeloid interaction and macrophage-abundant regions. Clinically, these myeloid cell populations, associated with an increased expression of the immune checkpoint protein TIM3, suggesting the presence of an immuno-suppressive environment, were associated with inferior survival outcomes. Importantly, we identified an immunophenotype signature based on the presence of 4 myeloid cell populations significantly associated with progression free survival in our cohort. Our study underscored the need for accurate identification of immune cell populations influencing tumor progression, offering valuable insights for the identification of prognostic markers, and for the development of effective therapeutic strategies, such as immune checkpoint inhibitors, for the treatment of pLGG.
The glutathione S-transferase pi gene (GSTP1) is a polymorphic gene encoding functionally different Gstp1 isoenzyme proteins. These seem to contribute to xenobiotic metabolism and might also play a ...role in susceptibility to cancer. The aim of this study was to elucidate the potential role of GSTP1 as a biomarker for disease progression and predictor of chemotherapeutic effect in glioma.
Using quantitative real time PCR and western blotting analysis, a total of 61 astrocytic tumor samples from WHO grade II-IV were investigated.
There were no differences in GSTP1 mRNA expression between diffuse astrocytomas, anaplastic astrocytomas, or GBM. No difference was seen between secondary GBM before and after radio-/chemotherapy.
The expression of GSTP was highly heterogeneous within the surgical specimens. No significant differences in gene and protein expression were detected between the different types of gliomas, suggesting that glioma chemoresistance is probably multifactorial and GSTP1-independent.
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