Over the last few years, advanced neuroimaging has provided unprecedented tools to improve glioma diagnosis and treatment. Magnetic resonance spectroscopy (MRS), perfusion-weighted imaging (PWI), and amino acid positron emission tomography (PET) are receiving increasing attention for purposes of treatment planning and response assessment in patients with diffuse gliomas, so that they are now part of the clinical armamentarium of most neuro-oncology centers. The present issue of Clinical and Translational Imaging focuses on the clinical implications and the changes in daily practice occurring as a result of the growing use of advanced neuroimaging modalities. As finely depicted by the articles of this issue, all the steps of patient care are being transformed by the availability of advanced neuroimaging, including (1) prognostic assessment [1], (2) multidisciplinary discussion [2], (3) planning and performing surgery [3,4,5], (4) response assessment after cytotoxic or targeted treatments [6,7,8], and (5) the identification of new therapeutic strategies [9] (Fig. 1).

Fig. 1
figure 1

Steps of patient care are transformed by the availability of advanced neuroimaging studies. Created with BioRender.com

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The prognostic stratification of diffuse gliomas relies on known individual factors including patient’s age, performance status, histology, and extent of resection [1]. Indeed, in recent years, molecular markers have gained increasing importance for purposes of prognostication, so that several have become relevant for grade assignment according to the latest WHO classification [10], including CDKN2A/B homozygous deletion in IDH-mutant gliomas and TERT promoter mutation, EGFR amplification, and combined chromosome 10 gain/7 loss in IDH-wild-type gliomas. This explains why the noninvasive identification of molecular markers by means of neuroimaging or liquid biopsy is one of the busiest areas of research in neuro-oncology.

A multidisciplinary team—composed by neurosurgeons, neuro-radiologists, nuclear medicine physicians, pathologists, molecular biologists, radiation oncologists, and neuro-oncologists—has become essential for a thoughtful synthesis of clinical, neuroimaging, and histo-molecular findings [2] and for coordinating treatment decisions. The importance of a multidisciplinary approach, ideally by a dedicated multidisciplinary tumor board, is being increasingly emphasized in international guidelines [11] and should be considered a priority in all neuro-oncology centers.

Surgical excision has high relevance in the context of diffuse gliomas to alleviate patient’s symptoms, to reduce the volume receiving radiation and improve survival. The last 10 years has seen a great improvement of surgical techniques, enabling a more precise excision of the tumor thanks to the use of fluorescent dyes, intraoperative ultrasound and magnetic resonance imaging (MRI). As outlined in the present issue [3, 4], it exists solid evidence, embraced by the EANO and RANO groups [12, 13], that amino acid PET can assist in the discrimination between neoplastic and non-neoplastic tissue and in the identification of hotspots for biopsy. It is instead still in its infancy the use of radio-guided surgery, a technique enabling to identify intraoperatively, using a detection probe, neoplastic lesions that have been preoperatively marked with a radiotracer. As reviewed by Collamati et al. [5], limited data are currently available on the use of radio-guided approaches for brain tumor surgery, although the widespread availability of PET and novel radiopharmaceuticals might open interesting avenues.

A challenging issue for clinicians is the assessment of tumor response after radiation due to overlapping tumor progression and treatment-related changes. As reviewed in the present issue, MRS, PWI, and PET might assist in the differential diagnosis between pseudo-progression and true progression [6, 7], providing relevant data for informed treatment decisions. In this context, the contribution of amino acid PET might be of high value [12, 13], strengthening evidence for a change in treatment when the results of advanced MRI techniques are not conclusive. Amino acid PET might also help to formulate survival estimates [7, 8], further expanding the range of applications of PET studies in neuro-oncology.

Despite all therapeutic measures, the overall survival of malignant gliomas remains poor, the identification of alternative strategies being long overdue. Immunotherapies directed at uplifting the state of local immune suppression by targeting the tumor microenvironment are currently being experimented in the context of clinical trials [9]. By helping to define immune cell infiltration, radiomics [9] and immuno-PET [3] studies might represent a fine complement for patient selection and longitudinal monitoring in immune therapy trials, encouraging research in this area.

It seems that we have just started seizing all the potential of advanced neuroimaging studies.

Final note

Inspired by ideas originated in the Scientific Committee of the Association, a COST action, which has stimulated the interest of researchers from 20 nations, has been promoted. Starting from this initial experience, based on a network called IMATRe (Imaging May Accelerate Translational Research), a multicenter trial connecting preclinical and clinical scientists is being activated to acquire in a relatively short time rigorous and statistically significant data to better understand, diagnose and cure patients affected with cerebral tumors. If a multidisciplinary team is needed to better define the fate of each patient, we believe that the hitherto unsatisfactory history of research on the rare and difficult-to-treat brain tumors can benefit from the creation of an international network that works together toward the same ambitious and difficult goal.