Foundation laid for improved diagnostic imaging of brain tumors

Diffuse gliomas are malignant brain tumors that cannot be optimally examined by means of conventional MRI imaging. So-called amino acid PET scans are better able to image the activity and spread of gliomas. An international team of researchers (RANO Working Group), led by scientists from LMU and the Medical University of Vienna, has now drawn up the first ever international criteria for the standardized imaging of gliomas using amino acid PET. It has published its results in the prestigious journal The Lancet Oncology.

Under the joint leadership of nuclear physician Nathalie Albert from LMU and oncologist Professor Matthias Preusser from the Medical University of Vienna, the RANO group has developed new criteria for assessing the success of therapies for diffuse gliomas. These malignant brain tumors develop out of glial cells in the brain. Tumors of this kind are generally aggressive and difficult to treat. The RANO group has developed criteria that permit evaluation of the success of treatment using positron emission tomography (PET). Called PET RANO 1.0, these PET-based criteria open up new possibilities for the standardized assessment of diffuse gliomas.

Comparable criteria now available for interpreting PET images

PET is an imaging technique that uses a radioactive tracer to measure metabolic processes in the body. Amino acid PET is used in the diagnosis of diffuse gliomas, with tracers that work on a protein basis (amino acids) and accumulate in brain tumors. Nathalie Albert explains: “PET imaging with radioactively labeled amino acids has proven extremely valuable in neuro-oncology and permits reliable representation of the activity and extension of gliomas. Although amino acid PET has been used for years, it had not been evaluated in a structured manner before now. In contrast to MRI-based diagnostics, there have been no criteria for interpreting these PET images.” According to the researchers, the new criteria allow PET to be used in clinical studies and everyday clinical practice and create a foundation for future research and the comparison of treatments for improved therapies.

The Response Assessment in Neuro-Oncology (RANO) Working Group is an international, multidisciplinary consortium founded to develop standardized new response criteria for clinical studies relating to brain tumors. Comprising experts from various fields, the group has been developing criteria to serve as standard references for assessing various clinically relevant aspects for more than a decade.

Nathalie Albert et al.: PET-based response assessment criteria for diffuse gliomas (PET RANO 1.0): a report of the RANO group. The Lancet Oncology 2024