We appreciate the interest of our colleagues representing the European Low-Grade Glioma Network in the updated European Association for Neuro-Oncology (EANO) guidelines. 1 Such guidelines often represent a multidisciplinary consensus that aims at providing guidance also in areas where evidence from conclusive clinical studies is limited or absent. Our colleagues miss a specific reference to the value of radiological growth rates. If we did not think that the assessment of tumour growth by neuroimaging was important, we would