Prognostic stratification of newly diagnosed IDH-mutant gliomas by [18F]fluoroethyltyrosine and [11C]methionine PET - a retrospective, bicentric cohort study.

Background: Improved prognostic stratification including imaging-based parameters is needed to guide treatment decisions in IDH-mutant glioma.

Methods: In this bicentric retrospective study, 457 patients with IDH-mutant glioma and [18F]fluoroethyltyrosine or [11C]methionine positron emission tomography (PET) prior to radiotherapy or systemic treatment were included. Associations of maximum and mean tumor-to-background ratios (TBRmax/TBRmean) and PET-positive volume (PET volume) with time to next intervention (TTNI) and overall survival (OS) were analyzed.

The role of amino acid PET in the era of checkpoint inhibitors and targeted therapy for brain tumor treatment.

Purpose Of Review: To summarize the role of diagnostic amino acid PET in the era of checkpoint inhibitors and targeted therapies for brain tumor treatment.

Recent Findings: Amino acid PET, particularly O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET, has shown promise in distinguishing treatment-related changes such as pseudoprogression and pseudoresponse from true tumor relapse in patients receiving immunotherapy or targeted therapies for brain metastases and gliomas, often outperforming conventional MRI. Additionally, serial amino acid PET imaging has demonstrated potential in early response assessment following these agents.

Update to the RANO working group and EANO recommendations for the clinical use of PET imaging in gliomas.

This Policy Review provides recommendations for the use of PET imaging in patients with gliomas and represents a joint effort of the Response Assessment in Neuro-Oncology (RANO) working group for PET and the European Association for Neuro-Oncology. The initial guideline was published in 2016, and summarised the previously established clinical benefit of PET with radiolabelled glucose and amino acid tracers in patients with gliomas. Since then, numerous additional studies have been published on this topic, focusing on differential diagnosis, prediction of molecular information, and prognostication.

Health-related quality of life and cognitive functioning in survivors of oligodendroglioma: an international cross-sectional investigation.

Background: Patients with oligodendroglioma have a relatively favourable prognosis. The long-term impacts of the tumour itself and its treatment on health-related quality of life (HRQOL) and cognition remain largely unclear. We investigated associations between treatment and functioning of survivors of oligodendroglioma.

Diagnosis of treatment-related changes in children and adolescents with brain and spinal tumors: a cost-effectiveness analysis using MRI and [18 F]FET PET.

Purpose: PET using the radiolabeled amino acid O-(2-[F]-fluoroethyl)-L-tyrosine ([F]FET) has considerable clinical value for follow-up evaluation of central nervous system tumors in children and adolescents. As medical procedures must be justified socio-economically, we determined cost-effectiveness of [F]FET PET for identification of treatment-related changes.

Methods: We analyzed clinical data from two different studies that assessed the value of FET PET to differentiate between brain and spinal tumor relapse and treatment-related changes in children and adolescents.

RANO criteria for response assessment of brain metastases based on amino acid PET imaging.

Novel diagnostic and therapeutic opportunities are needed to improve medical care and outcome of patients with brain metastases, a frequent and severe complication of several cancer types. Currently, magnetic resonance imaging (MRI) is the primary method used for detection, treatment planning and disease monitoring in patients with brain metastases, but this method has limitations. These limitations mean that MRI can inform on lesion size but cannot directly measure the activity or viability of tumor tissue.

Functional connectivity between tumor region and resting-state networks as imaging biomarker for overall survival in recurrent gliomas diagnosed by -(2-[F]fluoroethyl)-l-tyrosine PET.

Background: Amino acid PET using the tracer -(2-[F]fluoroethyl)-l-tyrosine (FET) is one of the most reliable imaging methods for detecting glioma recurrence. Here, we hypothesized that functional MR connectivity between the metabolic active recurrent tumor region and resting-state networks of the brain could serve as a prognostic imaging biomarker for overall survival (OS).

Methods: The study included 82 patients (26-81 years; median Eastern Cooperative Oncology Group performance score, 0) with recurrent gliomas following therapy (WHO-CNS 2021 grade 4 glioblastoma,  = 57; grade 3 or 4 astrocytoma,  = 12; grade 2 or 3 oligodendroglioma,  = 13) diagnosed by FET PET simultaneously acquired with functional resting-state MR.

Borderline Findings in -(2-[F]-Fluoroethyl)-l-Tyrosine PET of Patients with Suspected Glioma Relapse: Role in Clinical Practice.

One of the most common clinical indications for amino acid PET using the tracer -(2-[F]-fluoroethyl)-l-tyrosine (F-FET) is the differentiation of tumor relapse from treatment-related changes in patients with gliomas. A subset of patients may present with an uptake of F-FET close to recommended threshold values. The goal of this study was to investigate the frequency of borderline cases and the role of quantitative F-FET PET parameters in this situation.

The Value of Multidisciplinary Neuro-oncological Tumor Boards to Increase the Accuracy of FET PET for Identifying Brain Tumor Relapse.

Purpose: Especially in Europe, amino acid PET is increasingly integrated into multidisciplinary neuro-oncological tumor boards (MNTBs) to overcome diagnostic uncertainties such as treatment-related changes. We evaluated the accuracy of MNTB decisions that included the O -(2-[ 18 F]-fluoroethyl)-L-tyrosine (FET) PET information compared with FET PET results alone to differentiate tumor relapse from treatment-related changes.

Patients And Methods: In a single academic center, we retrospectively evaluated 180 MNTB decisions of 151 patients with CNS WHO grade 3 or 4 gliomas (n = 122) or brain metastases (n = 29) presenting equivocal MRI findings following anticancer treatment.

Evaluation of early metabolic changes following vorasidenib using FET PET in patients with -mutant gliomas.

The phase-3 INDIGO trial demonstrated that the isocitrate dehydrogenase () inhibitor vorasidenib significantly prolonged progression-free survival and delayed intervention in patients with CNS WHO grade 2 gliomas. However, conventional MRI showed limited response, with only 11% of patients having objective responses. Studies suggest that serial PET imaging with radiolabeled amino acids, such as -(2-[ F]-fluoroethyl)-L-tyrosine (FET) PET, may provide earlier and more informative assessments of treatment response than MRI.

MRI and F-FET PET for Multimodal Treatment Monitoring in Patients with Brain Metastases: A Cost-Effectiveness Analysis.

PET using the radiolabeled amino acid -(2-[F]fluoroethyl)-l-tyrosine (F-FET) has been shown to be of value for treatment monitoring in patients with brain metastases after multimodal therapy, especially in clinical situations with equivocal MRI findings. As medical procedures must be justified socioeconomically, we determined the effectiveness and cost-effectiveness of F-FET PET for treatment monitoring of multimodal therapy, including checkpoint inhibitors, targeted therapies, radiotherapy, and combinations thereof in patients with brain metastases secondary to melanoma or non-small cell lung cancer. We analyzed already-published clinical data and calculated the associated costs from the German statutory health insurance system perspective.

Advances in PET imaging for meningioma patients.

In patients with meningioma, diagnosis and treatment planning are predominantly based on anatomical imaging using MRI or CT. Constraints of these imaging modalities include precise meningioma delineation-especially at the skull base, in the case of -osseus growth, and in tumors with complex geometry-and the differentiation of post-therapeutic reactive changes from meningioma relapse. Advanced metabolic imaging using PET may help to characterize specific metabolic and cellular features providing additional information beyond the information derived from anatomical imaging alone.

Differentiation of a Falcine Meningioma From Cerebral Venous Sinus Thrombosis Using DOTATATE PET.

Differentiating brain tumors from nonneoplastic lesions using conventional MRI may be challenging. Clinical symptoms often remain unspecific, and imaging findings from MRI may be inconclusive. We present the case of a 23-year-old woman in whom an MRI suggested a cerebral venous sinus thrombosis.

Clinical applications and prospects of PET imaging in patients with IDH-mutant gliomas.

PET imaging using radiolabeled amino acids in addition to MRI has become a valuable diagnostic tool in the clinical management of patients with brain tumors. This review provides a comprehensive overview of PET studies in glioma patients with a mutation in the isocitrate dehydrogenase gene (IDH). A considerable fraction of these tumors typically show no contrast enhancement on MRI, especially when classified as grade 2 according to the World Health Organization classification of Central Nervous System tumors.

An updated review on the diagnosis and assessment of post-treatment relapse in brain metastases using PET.

Introduction: Brain metastases in patients with extracranial cancer are typically associated with increased morbidity and mortality. Stereotactic radiotherapy and immunotherapy using checkpoint inhibitors currently are essential in brain metastases treatment. Since conventional contrast-enhanced MRI alone cannot reliably differentiate between treatment-induced changes and brain metastasis relapse, several studies investigated the role of PET imaging and, more recently, radiomics, based on routinely acquired PET images, to overcome this clinically relevant challenge.

Prediction of response to lomustine-based chemotherapy in glioma patients at recurrence using MRI and FET PET.

Background: We evaluated O-(2-[18F]fluoroethyl)-l-tyrosine (FET) PET and MRI for early response assessment in recurrent glioma patients treated with lomustine-based chemotherapy.

Methods: Thirty-six adult patients with WHO CNS grade 3 or 4 gliomas (glioblastoma, 69%) at recurrence (median number of recurrences, 1; range, 1-3) were retrospectively identified. Besides MRI, serial FET PET scans were performed at baseline and early after chemotherapy initiation (not later than two cycles).

Two Decades of Brain Tumour Imaging with O-(2-[F]fluoroethyl)-L-tyrosine PET: The Forschungszentrum Jülich Experience.

O-(2-[F]fluoroethyl)-L-tyrosine (FET) is a widely used amino acid tracer for positron emission tomography (PET) imaging of brain tumours. This retrospective study and survey aimed to analyse our extensive database regarding the development of FET PET investigations, indications, and the referring physicians' rating concerning the role of FET PET in the clinical decision-making process. Between 2006 and 2019, we performed 6534 FET PET scans on 3928 different patients against a backdrop of growing demand for FET PET.

Efficacy and tolerability of regorafenib in pretreated patients with progressive CNS grade 3 or 4 gliomas.

Background: The phase 2 REGOMA trial suggested an encouraging overall survival benefit in glioblastoma patients at first relapse treated with the multikinase inhibitor regorafenib. Here, we evaluated the efficacy and side effects of regorafenib in a real-life setting.

Methods: From 2018 to 2021, 30 patients with progressive WHO CNS grade 3 or 4 gliomas treated with regorafenib (160 mg/day; first 3 weeks of each 4-week cycle) with individual dose adjustment depending on toxicity were retrospectively identified.