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Background Systemic infiltration of the brain by tumor cells is a hallmark of glioma pathogenesis which may cause disturbances in functional connectivity. We hypothesized that aggressive high-grade tumors cause more damage to functional connectivity than low-grade tumors. Methods We designed an imaging tool based on resting-state functional (f)MRI to individually quantify abnormality of functional connectivity and tested it in a prospective cohort of patients with newly diagnosed glioma. Results Thirty-four patients were analyzed (World Health Organization [WHO] grade II, n = 13; grade III, n = 6; grade IV, n = 15; mean age, 48.7 y). Connectivity abnormality could be observed not only in the lesioned brain area but also in the contralateral hemisphere with a close correlation between connectivity abnormality and aggressiveness of the tumor as indicated by WHO grade. Isocitrate dehydrogenase 1 (IDH1) mutation status was also associated with abnormal connectivity, with more alterations in IDH1 wildtype tumors independent of tumor size. Finally, deficits in neuropsychological performance were correlated with connectivity abnormality. Conclusion Here, we suggested an individually applicable resting-state fMRI marker in glioma patients. Analysis of the functional connectome using this marker revealed that abnormalities of functional connectivity could be detected not only adjacent to the visible lesion but also in distant brain tissue, even in the contralesional hemisphere. These changes were associated with tumor biology and cognitive function. The ability of our novel method to capture tumor effects in nonlesional brain suggests a potential clinical value for both individualizing and monitoring glioma therapy.

For meningiomas, the 2016 revision of the WHO classification introduced brain invasion per se as a sufficient condition to classify as grade II. We analyzed whether meningiomas previously graded as WHO grade I differ in prognosis depending on the presence of microscopic brain invasion. A consecutive series of patients with intracranial meningioma WHO grade I (± brain invasion) at two neurosurgical departments was analyzed retrospectively. Cox regression models on progression-free survival (PFS) and Kaplan–Meier survival estimates were performed. 875 adult patients were included. Histological diagnosis of brain invasion was confirmed in 28 patients. Median follow-up was 73 months. In univariate and multivariate models, gross total resection gained favorable prognostic influence for PFS (p

TERT promoter mutations have been associated with increased risk of recurrence in meningioma cohorts, thus a potential biomarker for aggressive phenotypes. A main purpose of refining tumour classification is better predictions on the patient level. We compiled data from previous published cohorts to investigate patient-level predictions of recurrence based on TERTp-mut status. Implementation of TERTp-mut into the WHO grading led to better patient prognostication by improved prediction of recurrence. Our results support implementation of TERTp-mut into diagnostics and classification of meningiomas.

Background: IDHwt diffuse gliomas represent the tumor entity with one of the worst clinical outcomes. Only rare cases present with a long-term survival of several years. Here we aimed at comparing the uptake characteristics on dynamic 18F-FET PET, clinical and molecular genetic parameters of long-term survivors (LTS) versus short-term survivors (STS): Methods: Patients with de-novo IDHwt glioma (WHO grade III/IV) and 18F-FET PET prior to any therapy were stratified into LTS (≥36 months survival) and STS (≤15 months survival). Static and dynamic 18F-FET PET parameters (mean/maximal tumor-to-background ratio (TBRmean/max), biological tumor volume (BTV), minimal time-to-peak (TTPmin)), diameter and volume of contrast-enhancement on MRI, clinical parameters (age, sex, Karnofksy-performance-score), mode of surgery, initial treatment and molecular genetics were assessed and compared between LTS and STS. Results: Overall, 75 IDHwt glioma patients were included (26 LTS, 49 STS). LTS were significantly younger (p &lt, 0.001), had a higher rate of WHO grade III glioma (p = 0.032), of O(6)-Methylguanine-DNA methyltransferase (MGMT) promoter methylation (p &lt, 0.001) and missing Telomerase reverse transcriptase promoter (TERTp) mutations (p = 0.004) compared to STS. On imaging, LTS showed a smaller median BTV (p = 0.017) and a significantly longer TTPmin (p = 0.008) on 18F-FET PET than STS, while uptake intensity (TBRmean/max) did not differ. In contrast to the tumor-volume on PET, MRI-derived parameters such as tumor size as well as all other above-mentioned parameters did not differ between LTS and STS (p &gt, 0.05 each). Conclusion: Besides molecular genetic prognosticators, a long survival time in IDHwt glioma patients is associated with a longer TTPmin as well as a smaller BTV on 18F-FET PET at initial diagnosis. 18F-FET uptake intensity as well as the MRI-derived tumor size (volume and maximal diameter) do not differ in patients with long-term survival.

TSPO-PET tracers are sensitive to a single-nucleotide polymorphism (rs6971-SNP), resulting in low-, medium- and high-affinity binders (LABs, MABs and HABS), but the clinical relevance of [18F]GE-180 is still unclear. We evaluated the impact of rs6971-SNP on in vivo [18F]GE-180 binding in a healthy brain and in pseudo-reference tissue in neuro-oncological and neurodegenerative diseases. Standardized uptake values (SUVs) of [18F]GE-180-PET were assessed using a manually drawn region of interest in the frontoparietal and cerebellar hemispheres. The SUVs were compared between the LABs, MABs and HABs in control, glioma, four-repeat tauopathy (4RT) and Alzheimer’s disease (AD) subjects. Second, the SUVs were compared between the patients and controls within their rs6971-subgroups. After excluding patients with prior therapy, 24 LABs (7 control, 5 glioma, 6 4RT and 6 AD) were analyzed. Age- and sex-matched MABs (n = 38) and HABs (n = 50) were selected. The LABs had lower frontoparietal and cerebellar SUVs when compared with the MABs and HABs, but no significant difference was observed between the MABs and HABs. Within each rs6971 group, no SUV difference between the patients and controls was detected in the pseudo-reference tissues. The rs6971-SNP affects [18F]GE-180 quantification, revealing lower binding in the LABs when compared to the MABs and HABs. The frontoparietal and cerebellar ROIs were successfully validated as pseudo-reference regions.

A 25-year-old man presented with headache and intracranial pressure symptoms. On MRI, an intracranial lesion was detected in the right thalamus with exophytic growth into the third ventricle and inhomogeneous contrast enhancement without necrosis. Dual amino acid (F-FET) and TSPO (F-GE-180) PET imaging showed high tumor-to-background ratios in both scans and a short time-to-peak in F-FET uptake dynamics. Biopsy revealed a diffuse midline glioma, H3K27M-mutant (WHO grade IV), a novel entity in the 2016 WHO classification with poor clinical outcome. Our case shows that the highly aggressive features of this tumor entity can be visualized in vivo by both PET modalities.

Glioblastomas are the most common form of malignant primary brain tumor and an important cause of morbidity and mortality. In recent years there have been important advances in understanding the molecular pathogenesis and biology of these tumors, but this has not translated into significantly improved outcomes for patients. In this consensus review from the Society for Neuro-Oncology (SNO) and the European Association of Neuro-Oncology (EANO), the current management of isocitrate dehydrogenase wildtype (IDHwt) glioblastomas will be discussed. In addition, novel therapies such as targeted molecular therapies, agents targeting DNA damage response and metabolism, immunotherapies, and viral therapies will be reviewed, as well as the current challenges and future directions for research.

The advent of immunotherapy using immune checkpoint inhibitors (ICIs) and targeted therapy (TT) has dramatically improved the prognosis of various cancer types. However, following ICI therapy or TT—either alone (especially ICI) or in combination with radiotherapy—imaging findings on anatomical contrast-enhanced MRI can be unpredictable and highly variable, and are often difficult to interpret regarding treatment response and outcome. This review aims at summarizing the imaging challenges related to TT and ICI monotherapy as well as combined with radiotherapy in patients with brain metastases, and to give an overview on advanced imaging techniques which potentially overcome some of these imaging challenges. Currently, major evidence suggests that imaging parameters especially derived from amino acid PET, perfusion-/diffusion-weighted MRI, or MR spectroscopy may provide valuable additional information for the differentiation of treatment-induced changes from brain metastases recurrence and the evaluation of treatment response.

Transcriptional activating mutations in the promoter region of the telomerase reverse transcriptase (TERT) gene occur at high frequency in various types of solid tumors and have also been reported for meningiomas. Especially for atypical and anaplastic meningiomas, the prognostic relevance of TERT promoter mutation is yet unclear. The present study aimed to analyze the frequency of TERT promoter mutation and define its long-term prognostic significance beyond clinical and histological factors in a cohort of meningiomas WHO grade II and III. Patients undergoing surgical resection of aggressive meningiomas were included. Analysis for C228T and C250T mutation in the TERT promoter region was performed using PCR method. Patients were stratified into two groups (TERT mutated vs. TERT wild type). Univariate analysis was conducted using molecular and histological factors. 87 patients with atypical (N = 72) and anaplastic meningiomas (N = 15) were included in the study. TERT promoter region was found to be mutated in 4 WHO grade II and 2 WHO grade III meningiomas. TERT promoter mutation was associated with shorter progression free survival than TERT wild type meningiomas (median PFS 12.5 vs. 26 months, p = .004). In the univariate analysis, TERT promoter mutation had a strong prognostic value on overall survival (p = .009) and progression free survival. Presence of TERT promoter mutation is associated with shorter progression free survival and overall survival in meningiomas WHO grade II and III. In these tumors, TERT promoter mutation should be considered as a clinically relevant prognostic factor to identify high risk patients.

Ependymal tumors are rare CNS tumors and may occur at any age, but their proportion among primary brain tumors is highest in children and young adults. Thus, the level of evidence of diagnostic and therapeutic interventions is higher in the pediatric compared with the adult patient population. The diagnosis and disease staging is performed by craniospinal MRI. Tumor classification is achieved by histological and molecular diagnostic assessment of tissue specimens according to the World Health Organization (WHO) classification 2016. Surgery is the crucial initial treatment in both children and adults. In pediatric patients with intracranial ependymomas of WHO grades II or III, surgery is followed by local radiotherapy regardless of residual tumor volume. In adults, radiotherapy is employed in patients with anaplastic ependymoma WHO grade III, and in case of incomplete resection of WHO grade II ependymoma. Chemotherapy alone is reserved for young children

OBJECTIVE Spinal cord hemangioblastomas are rare benign tumors developing either sporadically or as part of von Hippel-Lindau (VHL) disease. Generally, resection is the treatment of choice. However, the significance of intraoperative neurophysiological monitoring (IONM) for resection and postoperative outcome is still controversial. The authors analyzed the surgical and clinical courses of patients who had undergone resection of spinal cord hemangioblastoma, with special attention to preoperative imaging, the use of IONM, and short- and long-term outcomes. METHODS A series of 24 patients (male/female 1:1, lesion sporadic/associated with VHL 2.4:1) who had undergone 26 operations for the resection of 27 spinal cord hemangioblastomas was analyzed. All patients had undergone pre- and postoperative contrast-enhanced MRI. In all cases, microsurgical tumor removal had been performed under continuous IONM of both somatosensory and transcranial motor evoked potentials as well as electromyographic recording. Clinical characteristics, imaging findings, and operative records were retrospectively analyzed. Outcome parameters included short- and long-term status as regards sensorimotor deficits and a questionnaire on general performance, patient satisfaction, and Oswestry Disability Index (ODI) at the end of the follow-up period. The impact of IONM findings on postoperative deficits and outcome parameters as well as risk factors affecting functional prognosis was statistically assessed. RESULTS Preoperative symptoms (mean duration 16.2 ± 22.0 months) included sensory changes (100.0%), pain (66.7%), spinal ataxia (66.7%), motor deficit (41.7%), and bladder/bowel dysfunction (12.5%). Average age at the first operation was 36.8 ± 12.8 years. Most tumors (21 intramedullary, 6 intra- and/or extramedullary) were located dorsally (92.6%) and cervically (77.8%) and were accompanied by peritumoral edema and/or syringomyelia (81.5%). Tumor resection was achieved via laminectomy for 15 tumors, hemilaminectomy for 5, laminoplasty for 6, and interlaminar approach for 1. Gross-total resection was accomplished for 26 tumors (96.3%) with no local tumor recurrence during follow-up. Intraoperative neurophysiological monitoring was nonpathological in 11 operations (42.3%) and pathological in 15 (57.7%). Patients with nonpathological IONM had significantly fewer new sensorimotor deficits (p = 0.005). Long-term follow-up evaluation (mean 7.9 ± 4.0 years postoperatively, 7 patients lost to follow-up) revealed a stable or improved McCormick myelopathy grade in 88.2% of the patients, and 88.2% reported a stable or improved overall outcome according to Odom's criteria. Long-term general performance was excellent with 88.2% having a WHO/Eastern Cooperative Oncology Group (ECOG) Performance Status grade ≤ 1, 76.5% a Karnofsky Performance Scale score ≥ 80, and 70.6% a Barthel Index (BI) of 100. The mean ODI (11.4% ± 12.5%) indicated only minimal disability. There was a significant correlation between pathological IONM findings and a worse long-term status according to the BI and ODI (p = 0.011 and 0.024, respectively). Additionally, VHL disease was a risk factor affecting functional prognosis (p = 0.044). CONCLUSIONS Microsurgical removal of spinal cord hemangioblastomas with IONM facilitates a satisfying long-term outcome for patients. Nonpathological IONM findings are associated with a lower risk of new sensorimotor deficits and correlate with a better overall long-term outcome. von Hippel–Lindau disease is a risk factor for a worse long-term prognosis.

International audience; The management of patients with brain metastases has become a major issue due to the increasing frequency and complexity of the diagnostic and therapeutic approaches. In 2014, the European Association of Neuro-Oncology (EANO) created a multidisciplinary Task Force to draw evidence-based guidelines for patients with brain metastases from solid tumors. Here, we present these guidelines, which provide a consensus review of evidence and recommendations for diagnosis by neuroimaging and neuropathology, staging, prognostic factors, and different treatment options. Specifically, we addressed options such as surgery, stereotactic radiosurgery/stereotactic fractionated radiotherapy, whole-brain radiotherapy, chemotherapy and targeted therapy (with particular attention to brain metastases from non-small cell lung cancer, melanoma and breast and renal cancer), and supportive care.

The level of evidence to provide treatment recommendations for vestibular schwannoma is low compared with other intracranial neoplasms. Therefore, the vestibular schwannoma task force of the European Association of Neuro-Oncology assessed the data available in the literature and composed a set of recommendations for health care professionals. The radiological diagnosis of vestibular schwannoma is made by magnetic resonance imaging. Histological verification of the diagnosis is not always required. Current treatment options include observation, surgical resection, fractionated radiotherapy, and radiosurgery. The choice of treatment depends on clinical presentation, tumor size, and expertise of the treating center. In small tumors, observation has to be weighed against radiosurgery, in large tumors surgical decompression is mandatory, potentially followed by fractionated radiotherapy or radiosurgery. Except for bevacizumab in neurofibromatosis type 2, there is no role for pharmacotherapy.

2517 Background: Previously, we identified a prognostic 4-miRNA signature (built from let-7a-5p, let-7b-5p, miR-125a-5p and miR-615-5p) in glioblastoma patients treated according to the EORTC26981/22981-NCIC CE3 protocol. We present results of a novel external validation and will report on a completed prospective study on blood plasma samples of glioblastoma patients prior to chemoradiotherapy (CRT). Methods: The external validation cohort (n = 103) contained IDH1/2 wildtype tumors with known MGMT promoter methylation from the LMU-Munich (n = 37), the University Hospital Düsseldorf (n = 33) and TCGA (n = 33). Risk groups from the combination of miRNA signature with MGMT promoter methylation were analyzed for overall survival (OS) and prognostic performance using C-index. Within the prospective study (n = 52), blood samples were taken prior to RT, on d42 and d84 (22 cases analyzed up to now). Risk scores were obtained from signature miRNA expression levels in resection or biopsy specimen (retrospective, endpoint OS) and blood plasma (prospective, PFS). Results: The 4-miRNA signature was independent of sex and MGMT promoter methylation (p > 0.1) and defined high-risk (n = 47, med. OS: 16.4months) and low-risk (n = 56, med. OS: 26.9months) patients (HR: 2.08, 95%CI: 1.25-3.46, p = 0.004). Patients with methylated (med. OS: 23.7months, n = 54) compared to non-methylated MGMT promoter (med. OS: 16.8months, n = 49) had superior OS (p = 0.007, HR: 0.48, 95%-CI: 0.28-0.82). Combining the 4-miRNA signature and MGMT promoter methylation resulted in the signature-low-risk/ MGMT-promoter-methylated (med. OS: 37.4months), signature-low-risk/ MGMT-promoter-unmethylated (med. OS: 24.7months), signature-high-risk/ MGMT-promoter-methylated (med. OS: 16.4 months) and signature-high-risk/ MGMT-unmethylated groups (med. OS: 14.3months, Log-rank p = 0.002) with superior prediction performance. Conclusions: We confirmed the 4-miRNA signature as an independent prognosticator in IDH-wildtype glioblastoma while combination with MGMT promoter methylation outperformed other established prognostic factors. Our hypothesis is, that blood plasma samples will allow the risk stratification of glioblastoma patients before CRT. Phenotypic alterations driving its prognostic value remain to be determined and will allow for 1) risk stratified trials, 2) pathway analysis and targeting and 3) testing in healthy subjects to elucidate its screening potential.

PET targeting the translocator protein (TSPO) represents an interesting approach for glioma visualization, as TSPO is highly expressed in tumor cells. We present a 32-year-old man with recurrent glioblastoma after multimodal treatment. PET with the novel TSPO ligand F-GE-180 was performed after reirradiation. Here, the previously reirradiated tumor showed a remaining circular TSPO expression. Moreover, cerebrospinal fluid dissemination was detected by a high focal uptake at the right lateral and at the fourth ventricle, whereas only a faint contrast enhancement was present in MRI. This case demonstrated the diagnostic potential of TSPO-PET for glioma imaging by visualizing even minimal disease burden.

A 43-year-old woman with suspected recurrence of atypical meningioma World Health Organization grade II presented extensive intracranial lesions with high Ga-DOTATATE uptake. Moreover, numerous Ga-DOTATATE-positive bone, lung, and liver lesions were seen. For final diagnosis, biopsies taken from a lung lesion revealed distant metastases of the atypical meningioma. This case underlines the high diagnostic power of Ga-DOTATATE PET/CT for the staging of meningioma even beyond cerebral or spinal lesions; in case of distant lesions in patients with known meningioma, differential diagnosis should also contain metastases despite their rare occurrence. Moreover, this case emphasizes radioligand therapy especially in metastatic meningioma.

IDH wild type (IDHwt) anaplastic astrocytomas WHO grade III (AA III) are associated with poor outcome. To address the possibilities of molecular subsets among astrocytoma or of diagnostic reclassification, we analyzed a series of 160 adult IDHwt tumors comprising 120 AA III and 40 diffuse astrocytomas WHO grade II (A II) for molecular hallmark alterations and established methylation and copy number profiles. Based on molecular profiles and hallmark alterations the tumors could be grouped into four major sets. 124/160 (78 %) tumors were diagnosed as the molecular equivalent of conventional glioblastoma (GBM), and 15/160 (9 %) as GBM-H3F3A mutated (GBM-H3). 13/160 (8 %) exhibited a distinct methylation profile that was most similar to GBM-H3-K27, however, lacked the H3F3A mutation. This group was enriched for tumors of infratentorial and midline localization and showed a trend towards a more favorable prognosis. All but one of the 120 IDHwt AA III could be assigned to these three groups. 7 tumors recruited from the 40 A II, comprised a variety of molecular signatures and all but one were reclassified into distinct WHO entities of lower grades. Interestingly, TERT mutations were exclusively restricted to the molecular GBM (78 %) and associated with poor clinical outcome. However, the GBM-H3 group lacking TERT mutations appeared to fare even worse. Our data demonstrate that most of the tumors diagnosed as IDHwt astrocytomas can be allocated to other tumor entities on a molecular basis. The diagnosis of IDHwt diffuse astrocytoma or anaplastic astrocytoma should be used with caution.

The Macdonald criteria and the Response Assessment in Neuro-Oncology (RANO) criteria define radiologic parameters to classify therapeutic outcome among patients with malignant glioma and specify that clinical status must be incorporated and prioritized for overall assessment. But neither provides specific parameters to do so. We hypothesized that a standardized metric to measure neurologic function will permit more effective overall response assessment in neuro-oncology.An international group of physicians including neurologists, medical oncologists, radiation oncologists, and neurosurgeons with expertise in neuro-oncology drafted the Neurologic Assessment in Neuro-Oncology (NANO) scale as an objective and quantifiable metric of neurologic function evaluable during a routine office examination. The scale was subsequently tested in a multicenter study to determine its overall reliability, inter-observer variability, and feasibility.The NANO scale is a quantifiable evaluation of 9 relevant neurologic domains based on direct observation and testing conducted during routine office visits. The score defines overall response criteria. A prospective, multinational study noted a90% inter-observer agreement rate with kappa statistic ranging from 0.35 to 0.83 (fair to almost perfect agreement), and a median assessment time of 4 minutes (interquartile range, 3-5).The NANO scale provides an objective clinician-reported outcome of neurologic function with high inter-observer agreement. It is designed to combine with radiographic assessment to provide an overall assessment of outcome for neuro-oncology patients in clinical trials and in daily practice. Furthermore, it complements existing patient-reported outcomes and cognition testing to combine for a global clinical outcome assessment of well-being among brain tumor patients.

Summary Background Cilengitide is a selective αvβ3 and αvβ5 integrin inhibitor. Data from phase 2 trials suggest that it has antitumour activity as a single agent in recurrent glioblastoma and in combination with standard temozolomide chemoradiotherapy in newly diagnosed glioblastoma (particularly in tumours with methylated MGMT promoter). We aimed to assess cilengitide combined with temozolomide chemoradiotherapy in patients with newly diagnosed glioblastoma with methylated MGMT promoter. Methods In this multicentre, open-label, phase 3 study, we investigated the efficacy of cilengitide in patients from 146 study sites in 25 countries. Eligible patients (newly diagnosed, histologically proven supratentorial glioblastoma, methylated MGMT promoter, and age ≥18 years) were stratified for prognostic Radiation Therapy Oncology Group recursive partitioning analysis class and geographic region and centrally randomised in a 1:1 ratio with interactive voice response system to receive temozolomide chemoradiotherapy with cilengitide 2000 mg intravenously twice weekly (cilengitide group) or temozolomide chemoradiotherapy alone (control group). Patients and investigators were unmasked to treatment allocation. Maintenance temozolomide was given for up to six cycles, and cilengitide was given for up to 18 months or until disease progression or unacceptable toxic effects. The primary endpoint was overall survival. We analysed survival outcomes by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00689221. Findings Overall, 3471 patients were screened. Of these patients, 3060 had tumour MGMT status tested; 926 patients had a methylated MGMT promoter, and 545 were randomly assigned to the cilengitide (n=272) or control groups (n=273) between Oct 31, 2008, and May 12, 2011. Median overall survival was 26·3 months (95% CI 23·8–28·8) in the cilengitide group and 26·3 months (23·9–34·7) in the control group (hazard ratio 1·02, 95% CI 0·81–1·29, p=0·86). None of the predefined clinical subgroups showed a benefit from cilengitide. We noted no overall additional toxic effects with cilengitide treatment. The most commonly reported adverse events of grade 3 or worse in the safety population were lymphopenia (31 [12%] in the cilengitide group vs 26 [10%] in the control group), thrombocytopenia (28 [11%] vs 46 [18%]), neutropenia (19 [7%] vs 24 [9%]), leucopenia (18 [7%] vs 20 [8%]), and convulsion (14 [5%] vs 15 [6%]). Interpretation The addition of cilengitide to temozolomide chemoradiotherapy did not improve outcomes; cilengitide will not be further developed as an anticancer drug. Nevertheless, integrins remain a potential treatment target for glioblastoma. Funding Merck KGaA, Darmstadt, Germany.

Ependymomas are tumors that typically occur with an age-based site preference, with adults harboring supratentorial and spinal tumors and pediatric tumors being mainly in the posterior fossa. Despite their similar histologic appearance, the prognosis varies significantly by age and tumor location, with a better prognosis in increasing age. The mainstay of treatment remains surgical excision with or without radiation therapy as the tumor biology is poorly understood and chemotherapy is generally considered to be ineffective. More recently, molecular biology data have increased our understanding of the genetic and epigenetic changes that drive these tumors, but still it will take a lot of effort to find effective chemotherapeutic regimens. Currently, we are trying to define a subset of tumors, for which radiation therapy can be avoided.

This guideline provides recommendations for the use of PET imaging in gliomas. The review examines established clinical benefit in glioma patients of PET using glucose ((18)F-FDG) and amino acid tracers ((11)C-MET, (18)F-FET, and (18)F-FDOPA). An increasing number of studies have been published on PET imaging in the setting of diagnosis, biopsy, and resection as well radiotherapy planning, treatment monitoring, and response assessment. Recommendations are based on evidence generated from studies which validated PET findings by histology or clinical course. This guideline emphasizes the clinical value of PET imaging with superiority of amino acid PET over glucose PET and provides a framework for the use of PET to assist in the management of patients with gliomas.

2029Background: Mutational status of the IDH1/2 gene and co-deletion of on chromosome 1p/19q (co-del 1p/19q) is gaining further relevance for the evaluation of clinical outcome in lower grade gliom...

2013Background: Benefit from temozolomide chemotherapy in glioblastoma is essentially limited to patients with tumors with O6-methylguanine DNA methyltransferase (MGMT) promoter methylation. The im...

To analyze efficacy, functional outcome, and treatment toxicity of low‐dose rate I‐125 brachytherapy (SBT) alone or in combination with best safe resection (in case of larger tumor volumes) as first‐line treatment for pediatric low‐grade gliomas (PLGGs) not suitable for complete resection. Consecutively treated (2000–2014) complex located circumscribed WHO grade I/II PLGGs were included. For small tumors (≤4 cm in diameter) SBT alone was performed; for larger tumors best safe resection and subsequent SBT was chosen. Temporary Iodine‐125 seeds were used (median reference dose: 54 Gy). Treatment response was estimated with the modified MacDonald criteria. Analysis of functional outcome included ophthalmological, endocrinological and neurological evaluation. Survival was analyzed with the Kaplan–Meier method. Prognostic factors were obtained from proportional hazards models. Toxicity was categorized according to the Common Terminology Criteria for Adverse Events. Fifty‐eight patients were included treated either with SBT alone (n = 39) or with SBT plus microsurgery (n = 19). Five‐year progression‐free survival was 87%. Two patients had died due to tumor progression. Among survivors, improvement/stabilization/deterioration of functional deficits was seen in 20/14/5 patients, respectively. Complete/partial response had beneficial impact on functional scores (P = 0.02). The 5‐year estimated risk to receive adjuvant radiotherapy/chemotherapy was 5.2%. The overall early (delayed) toxicity rate was 8.6% (10.3%), respectively. No permanent morbidity occurred. In complex located PLGGs, early SBT alone or combined with best safe resection preserves/improves functional scores and results in tumor control rates usually achieved with complete resection. Long‐term analysis is necessary for confirmation of these results.

The use of intraoperative neurophysiological monitoring (IONM) in neurosurgery has improved patient safety and outcomes. However, a pitfall in the use of IONM remains unsolved. Currently, there is no feasible way for surgeons to interpret IONM waves themselves during operations. Instead, they have to rely on verbal feedback from a neurophysiologist. This method is prone to communication failures, which can lead to delayed or false interpretation of the data. Direct visualization of IONM waves is a way to alleviate this problem and make IONM more effective. Microscope-integrated IONM (MI-IONM) was used in 163 cranial and spinal cases. We evaluated the feasibility, system stability and how well the system integrated into the surgical workflow. We used an IONM system that was connected to a surgical microscope. All IONM modalities used at our institution could be visualized as required, superimposed on the surgical field in the eyepiece of the microscope without obstructing the surgeon’s field of vision. Use of MI-IONM was safe and reliable. It furthermore provided valuable intraoperative information. The system merely required a short learning curve. Only minor system problems without impact on surgical workflow occurred. MI-IONM proved to be especially useful in surgical cases where careful monitoring of nerve function is required, e.g., cerebellopontine angle surgery. Here, direct assessment of surgical action and IONM wave change was provided to the surgeon, if necessary (on-off control). MI-IONM is a useful extension of conventional IONM that provides optional real-time functional information to the surgeon on demand.

Objective: The aim of this prospective longitudinal study was to identify static and dynamic O -(2-[ 18 F]fluoroethyl)-l-tyrosine PET ( 18 FET-PET)-derived imaging biomarkers in patients with glioblastoma (GBM). Methods: Seventy-nine patients with newly diagnosed GBM were included; 42 patients underwent stereotactic biopsy (unresectable tumors) and 37 patients microsurgical tumor resection. All patients were scheduled to receive radiotherapy plus concomitant and adjuvant temozolomide (RCx/TMZ). 18 FET-PET evaluation using static and dynamic analysis was done before biopsy/resection, after resection, 4 to 6 weeks following RCx, and after 3 cycles of TMZ. Endpoints were survival and progression-free-survival. Prognostic factors were obtained from proportional hazards models. Results: Biological tumor volume before RCx (BTV preRCx ) was the most important 18 FET-PET–derived imaging biomarker and was independent of MGMT promoter methylation and clinical prognostic factors: patients with smaller BTV preRCx had significantly longer progression-free and overall survival (OS). 18 FET time-activity curves (TACs) before treatment and their changes after RCx were also related to outcome; patients with initially increasing TACs experienced longer OS. Conclusion: BTV preRCx and TAC represent important 18 FET-PET–derived imaging biomarkers in GBM. Increasing TACs are associated with prolonged OS. The BTV preRCx is a strong prognostic factor for progression-free survival and OS independent of the mode of surgery. Our data furthermore suggest that patients harboring resectable GBM might benefit from maximal PET-guided tumor resection.

Purpose Intracavitary radioimmunotherapy (RIT) offers an effective adjuvant therapeutic approach in patients with malignant gliomas. Since differentiation between recurrence and reactive changes following RIT has a critical impact on patient management, the aim of this study was to analyse the value of serial O-(2-[18F]fluoroethyl)-l-tyrosine (FET) PET scans in monitoring the effects of this locoregional treatment. Methods Following conventional therapy, 24 glioma patients (5 WHO III, 19 WHO IV) underwent one to five RIT cycles with either 131I-labelled (n=19) or 188Re-labelled (n=5) anti-tenascin antibodies. Patients were monitored with serial FET PET scans (2–12 scans). For semiquantitative evaluation, maximal tumoural uptake (TUmax) was evaluated and the ratio to background (BG) was calculated. Results of PET were correlated with histopathological findings (n=9) and long-term clinical follow-up for up to 87 months. Results In seven tumour-free patients, PET revealed slightly increasing but homogeneous FET uptake surrounding the resection cavity with a peak up to 18 months following RIT (TUmax/BG 2.07±0.25) but stable or decreasing values during further follow-up (last follow-up: TUmax/BG 1.63±0.22). Seventeen patients developed regrowth of residual tumour/tumour recurrence showing additional nodular FET uptake (TUmax/BG 2.79±0.53). A threshold value of 2.4 (TUmax/BG) allowed best differentiation between recurrence and reactive changes (sensitivity 82%, specificity 100%). Conclusion FET PET is a sensitive tool for monitoring the effects of locoregional RIT. Homogeneous, slightly increasing FET uptake around the tumour cavity with a peak up to 18 months after RIT, followed by stable or decreasing uptake, points to benign, therapy-related changes. In contrast, nodular uptake is a reliable indicator of recurrence.

2013 Background: Glioblastomas in elderly patients are associated with particularly poor outcome, with only few patients demonstrating long-term survival (LTS). Methods: To better characterize clinical and molecular correlates of LTS in elderly glioblastoma patients, we searched the German Glioma Network (GGN) database for patients aged 71 years or more with histological confirmation of glioblastoma and survival of at least two years after diagnosis. Results: Of 2071 glioblastoma patients enrolled in the GGN from 2004-2012, 425 patients were aged 71 years or more; of these, 27 patients (6.4%) survived for 2 years or more (median survival: 37.1 months, 95% confidence interval: 30.0-44.2 months). A comparison of these 27 patients with the 398 patients who survived shorter than 2 years (median survival: 6.2, 95% confidence interval: 5.2-7.2 months) revealed more intensive up-front treatment and a trend towards higher initial Karnofsky performance score as distinguishing clinical factors. Molecular analyses additionally showed more frequent O6-methylguanine-DNA methyltransferase ( MGMT) promoter methylation in the LTS patients. Isocitrate dehydrogenase (IDH) mutation was restricted to single patients and the frequency of telomerase reverse transcriptase ( TERT) promoter mutation did not differ between groups. Genome-wide DNA copy number and methylation profiling using 450k microarray analysis performed for 16 LTS patients and 40 control patients revealed limited differential DNA methylation and no specific copy number profiles linked to LTS. Conclusions: Collectively, our findings confirm that LTS is rare in elderly patients with glioblastoma and that clinical and tumor-associated molecular factors linked to LTS resemble those in standard age patients, except for less common IDH mutation.

2038 Background: Ependymoma is a subtype of glioma that is rare in adults. Its classification has remained entirely morphological until recently, and surgery and radiotherapy remain the mainstays of treatment. Here we characterized DNA methylation profiles and their clinical correlates in the prospectively assembled cohort of the German Glioma Network. Methods: The GGN cohort was screened for patients diagnosed with myxopapillary ependymoma, subependymoma, classic ependymoma and anaplastic ependymoma for whom clinical data and remaining tumor tissue were available. Tumors were subjected to DNA methylation profiling using the Illumina Infinium HumanMethylation450 BeadChip platform. Molecular data were correlated with morphological tumor and clinical patient characteristics. Results: One hundred and twenty-two ependymoma patients with available tumor tissue were identified. Each adult tumor could be assigned to one of the previously defined methylation classes of ependymoma. Molecular entities of ependymal brain tumors display distinct copy-number variations. PF-EPN-B and ST-EPN-RELA tumors tend to have a worse prognosis than other ependymal subtypes in adults. Conclusions: Molecular classification of adult ependymal methylation subclasses should be implemented in routine diagnostics. Patients with PF-EPN-B and ST-EPN-RELA subtypes might benefit from early treatment beyond surgery.

Purpose of review Brain tumors differ in histology, biology, prognosis and treatment options. Although structural magnetic resonance is still the gold standard for morphological tumor characterization, molecular imaging has gained an increasing importance in assessment of tumor activity and malignancy. Recent findings Amino acid PET is frequently used for surgery and biopsy planning as well as therapy monitoring in suspected primary brain tumors as well as metastatic lesions, whereas 18F-fluorodeoxyglucose (18F-FDG) remains the tracer of choice for evaluation of patients with primary central nervous system lymphoma. Application of somatostatin receptor ligands has improved tumor delineation in skull base meningioma and concurrently opened up new treatment possibilities in recurrent or surgically not assessable tumors.Recent development focuses on the implementation of hybrid PET/MRI as well as on the development of new tracers targeting tumor hypoxia, enzymes involved in neoplastic metabolic pathways and the combination of PET tracers with therapeutic agents. Summary Implementation of molecular imaging in the clinical routine continues to improve management in patients with brain tumors. However, more prospective large sample studies are needed to validate the additional informative value of PET.

A 55-year-old man reported having recurrent spontaneous attacks of rotatory vertigo lasting 1–5 seconds and occurring up to 10 times daily and often associated with attacks of right ear tinnitus for more than 3 years. Caloric testing showed a right peripheral vestibular deficit. Cervical vestibular myogenic potentials showed impaired function of the right saccule. An audiogram was normal. MRI (figure, A and B) showed that the eighth nerve was in contact with the anterior inferior cerebellar artery. Vestibular paroxysmia was diagnosed.1,2 Carbamazepine resolved the symptoms but the patient discontinued it due to side effects. The symptoms recurred, and surgery was performed. Intraoperatively, compression of the eighth nerve was found (figure, C and D). He has had no further symptoms and takes no medication. These findings support the view that vascular compression of the root entry zone of the eighth cranial nerve can cause vestibular paroxysmia. The authors thank Dr. Jennifer Linn for evaluation of the MRI scans.

2042Background: Around 40% of glioblastomas exhibit amplification of the epidermal growth factor receptor (EGFR) gene; half of these tumors carry a specific genetic rearrangement characterized by deletion of exons 2-7 (EGFRvIII). The prognostic role of EGFRvIII in patients with EGFR-amplified glioblastoma and its expression in recurrent as opposed to newly diagnosed glioblastoma have not been defined. Such data are highly relevant for the clinical development of novel EGFRvIII-targeting agents. Methods: EGFR-amplified glioblastomas from 109 patients treated according to standard of care were assessed for EGFRvIII expression and data were correlated with outcome. Pairs of primary and recurrentglioblastomas from 38 of these patients (including 25 patients with EGFRvIII-positive tumors) and from 33 glioblastoma patients without EGFR amplification were evaluated for changes in EGFR amplification and EGFRvIII expression at recurrence. Results: Among 109 patients with EGFR-amplified primary glioblastoma, 63 had...

2058Background: Stratification of glial tumors according to IDH mutation and 1p/19q co-deletion status will gain further importance for tumor classification and treatment in the near future. In analogy, factors derived from 18FET-PET uptake dynamics such as time-to-peak (TTP) analysis allow discrimination between different prognostic groups. The present study aims at correlating molecular tumor characteristics and TTP analysis and to analyze associations with clinical outcome. Methods: 300 patients with de novo WHO grade II-IV gliomas with 18FET-PET imaging at diagnosis were grouped according to IDH mutation and 1p/19q co-deletion status into 3 subgroups (IDH wildtype, IDH mut/non co-del 1p/19q and IDH mut/co-del 1p/19q). Clinical and imaging factors such as age, Karnofsky performance status, treatment and 18FET-PET derived TTP analysis were analyzed with regard to progression-free and overall survival (PFS and OS) via univariate and multivariate regression analysis. Results: PFS and OS was longest in the...

Histological subtyping and grading by malignancy are the cornerstones of the World Health Organization (WHO) classification of tumors of the central nervous system. They shall provide clinicians with guidance as to the course of disease to be expected and the choices of treatment to be made. Nonetheless, patients with histologically identical tumors may have very different outcomes, notably in patients with astrocytic and oligodendroglial gliomas of WHO grades II and III. In gliomas of adulthood, 3 molecular markers have undergone extensive studies in recent years: 1p/19q chromosomal codeletion, O(6)-methylguanine methyltransferase (MGMT) promoter methylation, and mutations of isocitrate dehydrogenase (IDH) 1 and 2. However, the assessment of these molecular markers has so far not been implemented in clinical routine because of the lack of therapeutic implications. In fact, these markers were considered to be prognostic irrespective of whether patients were receiving radiotherapy (RT), chemotherapy, or both (1p/19q, IDH1/2), or of limited value because testing is too complex and no chemotherapy alternative to temozolomide was available (MGMT). In 2012, this situation has changed: long-term follow-up of the Radiation Therapy Oncology Group 9402 and European Organisation for Research and Treatment of Cancer 26951 trials demonstrated an overall survival benefit from the addition to RT of chemotherapy with procarbazine/CCNU/vincristine confined to patients with anaplastic oligodendroglial tumors with (vs without) 1p/19q codeletion. Furthermore, in elderly glioblastoma patients, the NOA-08 and the Nordic trial of RT alone versus temozolomide alone demonstrated a profound impact of MGMT promoter methylation on outcome by therapy and thus established MGMT as a predictive biomarker in this patient population. These recent results call for the routine implementation of 1p/19q and MGMT testing at least in subpopulations of malignant glioma patients and represent an encouraging step toward the development of personalized therapeutic approaches in neuro-oncology.

Cilengitide, a cyclicized arginine–glycine–aspartic acid-containing pentapeptide, potently blocks ανβ3 and ανβ5 integrin activation. Integrins are upregulated in many malignancies and mediate a wide variety of tumor–stroma interactions. Cilengitide and other integrin-targeting therapeutics have preclinical activity against many cancer subtypes including glioblastoma (GBM), the most common and deadliest CNS tumor. Cilengitide is active against orthotopic GBM xenografts and can augment radiotherapy and chemotherapy in these models. In Phase I and II GBM trials, cilengitide and the combination of cilengitide with standard temozolomide and radiation demonstrate consistent antitumor activity and a favorable safety profile. Cilengitide is currently under evaluation in a pivotal, randomized Phase III study (Cilengitide in Combination With Temozolomide and Radiotherapy in Newly Diagnosed Glioblastoma Phase III Randomized Clinical Trial [CENTRIC]) for newly diagnosed GBM. In addition, randomized controlled Phase II studies with cilengitide are ongoing for non-small-cell lung cancer and squamous cell carcinoma of the head and neck. Cilengitide is the first integrin inhibitor in clinical Phase III development for oncology.

2037 Background: Patients with an anaplastic glioma (WHO III°) without IDH1 mutation have a comparable disease course to glioblastoma. Dynamic 18FET-PET has been shown to provide prognostic informa...

2041 Background: The role of surgery for recurrent glioblastoma is under debate. Tumor volume at recurrence was prognostic in single-institution retrospective studies, but no data from prospective ...

2015 Background: Rechallenge with temozolomide (TMZ) at first progression of glioblastoma after radiotherapy with concomitant and maintenance temozolomide (TMZ/RT→TMZ) has been studied in retrospec...

2014 Background: The prognosis of glioblastoma remains poor: only a minority of patients experience long-term survival beyond three years after diagnosis. Previously identified predictors of long-t...

2027 Background: The determinants of long-term survival in glioblastoma have remained largely obscure. Isocitrate dehydrogenase (IDH) 1 or 2 mutations are common in WHO grade 2/3 gliomas, but rare in primary glioblastomas, and associated with longer survival. Methods: We compared clinical and molecular characteristics of 69 patients with centrally confirmed glioblastoma and survival > 36 months (LTS-36), including 33 patients surviving > 60 months (LTS-60), with 259 patients surviving < 36 months. MGMT promoter methylation, 1p/19q codeletions, EGFR amplification, TP53 mutations and IDH1/2mutations were determined by standard techniques. Results: The rate of IDH1/2 mutations in LTS-36 patients was 34% (23/67 patients) as opposed to 4.3% in controls (11/257 patients). Long-term survivors with IDH1/2 -mutant glioblastomas were younger, had almost no EGFR amplifications, but exhibited more often 1p/19q codeletions and TP53 mutations than LTS patients with IDH1/2 wild-type glioblastomas. Among LTS-36 patients, wild-type TP53 status, MGMT promoter methylation, and absence of EGFR amplification, but not IDH1/2 mutation, were associated with prolonged survival. Among 11 patients with IDH1/2-mutant glioblastomas without long-term survival, the only difference to IDH1/2-mutant long-term survivors was less frequent MGMT promoter methylation. Compared with LTS-36 patients, LTS-60 patients had been treated initially with radiotherapy alone and had TP53 mutations less frequently. Conclusions: IDH1/2 mutations define a subgroup of tumors of LTS patients that exhibit molecular characteristics of WHO grade 2/3 gliomas and secondary glioblastomas. Determinants of LTS with IDH1/2 wild-type glioblastomas, which exhibit typical molecular features of primary glioblastomas, beyond MGMT promoter methylation, remain to be identified.

2045 Background: Aim of this prospective longitudinal study was to evaluate whether 18FET-PET allow to monitor and quantify the therapeutic effects of surgery, radiotherapy and chemotherapy in newly diagnosed glioblastoma and whether 18FET-PET can provide additional prognostic information on response to therapy and outcome. Methods: 92 patients with newly diagnosed glioblastoma considered eligible for radiochemotherapy (RcX) were included; diagnosis was obtained by biopsy (n=46) or resection (n=46). Patients were to undergo 18FET-PET and cocomitant MRI scans prior to surgery, following RcX and as well as after three cycles of adjuvant temozolomide (TMZ). At each time point, biological tumor volume (BTV), maximal 18FET uptake as ratio to background (SUVmax/BG), and tumor uptake kinetics (TAC) were obtained. Overall survival (OS) was primary endpoint, progression-free survival (PFS) as defined by MRI using Macdonald criteria was a secondary endpoint. ROC analyses were done to determine optimal cut-off values of 18FET-PET parameters for survival outcome. To identify predictors for OS/PFS, Cox regression analysis was performed. Results: 79 patients were eligible for further evaluation. ROC analysis revealed cut-off values for pre-RCX BTV (9.5 ccm) and SUVmax/BG (2.95) with a sensitivity and specificity of both 70% for BTV and 68/73% for SUVmax/BG. Both pre-therapeutic BTV and SUVmax/BG were associated with PFS and OS (p18FET TAC pattern and its changes were related to OS and PFS. Conclusions: Serial 18FET-PET imaging in glioblastoma before and after concomitant radio-/chemotherapy is a highly powerful tool to provide prognostic information for the outcome in newly diagnosed glioblastoma patients. These findings might help to personalize therapy and response evaluation in forthcoming clinical investigations. Clinical trial information: NCT01089868.

Primary astrocytomas of grade 3 or 4 according to the classification system of the World Health Organization (high-grade astrocytomas or HGAs) are preponderant among adults and are almost invariably fatal despite the use of multimodal therapy. Here we show that the juvenile brain has an endogenous defense mechanism against HGAs. Neural precursor cells (NPCs) migrate to HGAs, reduce glioma expansion and prolong survival time by releasing endovanilloids that activate the vanilloid receptor (transient receptor potential vanilloid subfamily member-1 or TRPV1) on HGA cells. TRPV1 is highly expressed in tumor and weakly expressed in tumor-free brain. TRPV1 stimulation triggers tumor cell death through the branch of the endoplasmic reticulum stress pathway that is controlled by activating transcription factor-3 (ATF3). The antitumorigenic response of NPCs is lost with aging. NPC-mediated tumor suppression can be mimicked in the adult brain by systemic administration of the synthetic vanilloid arvanil, suggesting that TRPV1 agonists have potential as new HGA therapeutics. Citation Format: Michael Synowitz, Kristin Stock, Jitender Kumar, Stefania Petrosino, Roberta Imperatore, Ewan St J Smith, Peter Wend, Bettina Purfürst, Ulrike A Nuber, Ulf Gurok, Vitali Matyash, Joo-Hee Wälzlein, Sridhar R Chirasani, Gunnar Dittmar, Benjamin F Cravatt, Stefan Momma, Gary R Lewin, Alessia Ligresti, Luciano De Petrocellis, Luigia Cristino, Joerg Christian Tonn, Vincenzo Di Marzo, Helmut Kettenmann, Rainer Glass. Neural precursor cells induce cell death of high-grade astrocytomas through stimulation of TRPV1. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 215. doi:10.1158/1538-7445.AM2013-215

Background: We analyzed prospectively whether MGMT (O(6)-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression. 12 Hide Figures Abstract Introduction Methods Results Discussion Acknowledgments Author Contributions References Reader Comments (0) Figures Abstract Background We analyzed prospectively whether MGMT (O6-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression. Methodology/Principal Findings: Adult patients with a histologically proven malignant astrocytoma (glioblastoma: N = 53, anaplastic astrocytoma: N = 10) were included. MGMT promoter methylation was determined by methylation-specific PCR (MSP) and sequencing analysis. Expression of MGMT and DNMTs mRNA were analysed by real-time qPCR. Prognostic factors were obtained from proportional hazards models. Correlation between MGMT mRNA expression and MGMT methylation status was validated using data from the Cancer Genome Atlas (TCGA) database (N = 229 glioblastomas). Low MGMT mRNA expression was strongly predictive for prolonged time to progression, treatment response, and length of survival in univariate and multivariate models (p

BACKGROUND: Aim of this prospective longitudinal study was to identify static and dynamic O-(2-[18F]fluorethyl)-L-tyrosine PET (18FET-PET) derived imaging biomarkers in glioblastoma (GB) patients to obtain additional information concerning prognosis and monitoring of therapy. METHODS: 79 patients with newly diagnosed GB were included; 42 patients underwent stereotactic biopsy (unresectable tumors) and 37 patients microsurgical tumor resection. All patients were scheduled to receive radiotherapy plus concomitant and adjuvant temozolomide (RCx/TMZ). 18FET-PET evaluation using static and dynamic parameters was done prior to biopsy/resection, after resection, 4-6 weeks following RCx and after three cycles of TMZ. Endpoints were survival and progression-free-survival. Prognostic factors were obtained from proportional hazards models. RESULTS: Biological tumor volume before RCx (BTVpreRCx) was the most important 18FET-PET derived imaging biomarker and was independent of MGMT promoter methylation and clinical prognostic factors: patients with smaller BTVpreRCx had significant longer progression free (PFS) and overall survival (OS). 18FET time activity curves (TAC) before treatment and their changes after RCx were also related to outcome: patients with initially increasing TAC and those exhibiting a switch from decreasing to increasing TAC after RCx experienced longer progression-free-survival. CONCLUSIONS: BTVpreRCx and TAC represent important 18FET-PET-derived imaging biomarkers in GB. Increasing TAC are associated with prolonged PFS. The BTVpreRCx is a strong prognostic factor for PFS and OS independent of the mode of surgery. Our data furthermore suggest that patients harbouring resectable GB might benefit from maximal PET-guided tumor resection. SECONDARY CATEGORY: Clinical Neuro-Oncology.

Purpose Invasion and migration are key processes of glioblastoma and are tightly linked to tumor recurrence. Integrin inhibition using cilengitide has shown synergy with chemotherapy and radiotherapy in vitro and promising activity in recurrent glioblastoma. This multicenter, phase I/IIa study investigated the efficacy and safety of cilengitide in combination with standard chemoradiotherapy in newly diagnosed glioblastoma. Patients and Methods Patients (age ≥ 18 to ≤ 70 years) were treated with cilengitide (500 mg) administered twice weekly intravenously in addition to standard radiotherapy with concomitant and adjuvant temozolomide. Treatment was continued until disease progression or for up to 35 weeks. The primary end point was progression-free survival (PFS) at 6 months. Results Fifty-two patients (median age, 57 years; 62% male) were included. Six- and 12-month PFS rates were 69% (95% CI, 54% to 80%) and 33% (95% CI, 21% to 46%). Median PFS was 8 months (95% CI, 6.0 to 10.7 months). Twelve- and 24-month overall survival (OS) rates were 68% (95% CI, 53% to 79%) and 35% (95% CI, 22% to 48%). Median OS was 16.1 months (95% CI, 13.1 to 23.2 months). PFS and OS were longer in patients with tumors with O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation (13.4 and 23.2 months) versus those without MGMT promoter methylation (3.4 and 13.1 months). The combination of cilengitide with temozolomide and radiotherapy was well tolerated, with no additional toxicity. No pharmacokinetic interactions between temozolomide and cilengitide were identified. Conclusion Compared with historical controls, the addition of concomitant and adjuvant cilengitide to standard chemoradiotherapy demonstrated promising activity in patients with glioblastoma with MGMT promoter methylation.