Brain tumours, either primary or secondary, are frequent. Primary brain tumours include mainly glioma, lymphoma and meningioma. Secondary tumours, i.e. brain metastases, are a frequent event during the disease course of patients with cancer. The evaluation of response to treatment is often difficult with structural imaging due to the interference of treatment effects. In this chapter, the role of advanced imaging for the differential diagnosis between pseudoprogression, radiation necrosis and tumour recurrence is described with perfusion and diffusion MR imaging, MR spectroscopy and PET imaging with amino acid analogues, fluorodeoxyglucose and other tracers. Furthermore, the commonly used response criteria for various brain tumours are described. For glioma, those set out by the response assessment in neuro-oncology (RANO) group are recommended. For brain metastases the RANO-brain metastases (RANO-BM) and RECIST criteria are commonly used. While conventional T1w post-contrast imaging is the mainstay imaging modality for basic response assessment, multimodal imaging is commonly necessary to evaluate the response to treatment of primary and secondary brain tumours.

Medical Radiology
Department of Radiology

Gahrmann, R, Arbizu, J. (J.), Laprie, A. (A.), Morales, M. (M.), & Smits, M. (2020). Response evaluation and follow-up by imaging in brain tumours. In Imaging and Interventional Radiology for Radiation Oncology. doi:10.1007/978-3-030-38261-2_21