Tumour biology characterisation by imaging in clinic

Abstract

There have been advances in multiple imaging modalities in recent decades which allow more sophisticated and non-invasive means of characterising evolving aspects of tumour biology at all stages of their clinical course (i.e. diagnosis, staging, prognostication and therapy response). Particular applications include more accurate staging (e.g. highly sensitive and specific new PET tracers such as Ga-68 DOTATATE and PSMA, diffusion-weighted MRI), assessment of tumour aggressiveness and prognosis (with [18F]FDG PET, CT textural analysis) and tailoring therapy based on either initial assessment (biological dose painting) or interim response assessment ([18F]FDG PET). The field of theranostics takes imaging of tumour biology to the natural next step of applying information gained from imaging to choose and tailor radionuclide therapies. Some of these imaging advances have been evaluated in clinical trials or have already been incorporated into clinical practice. The major challenges of functional imaging modalities are reproducibility and standardisation of methodology and the cumbersome and time-consuming process of gathering the clinical evidence base, which can lag behind the rapid technological developments. Dynamic adaptation of radiotherapy plans informed by non-invasive imaging of multiple facets of tumour and normal tissue biology at multiple time points is now possible, and improved clinical outcomes need to be demonstrated in clinical trials.