Positron Emission Tomography-Computed Tomography (PET-CT) with injection of 18F-fluoroethylcholine (FEC) could be a useful tool in the evaluation and follow-up of patients who have been diagnosed with glioblastoma multiforme (GBM) and who are treated with radiotherapy and temozolomide by allowing, for example, the distinction of necrosis from tumour tissue. This tool could help the clinician in making therapeutic decisions for GBM patients.