Hodgkin lymphoma (HL) is a B-cell lymphoma accounting for 10% to 15% of all lymphoma in industrialised countries. It has a bimodal age distribution with one peak around the age of 30 years and another after the age of 60 years. Although HL accounts for fewer than 1% of all neoplasms worldwide, it is considered to be one of the most common malignancies in young adults and, with cure rates of 90%, one of the most curable cancers worldwide. Current treatment options for HL comprise more- or less-intensified regimens of chemotherapy plus radiotherapy, depending on disease stage. [18F]-fluorodeoxy-D-glucose (FDG)-positron emission tomography (PET, also called PET scanning) is an imaging tool that can be used to illustrate a tumour's metabolic activity, stage and progression. Therefore, it could be used as a standard interim procedure during HL treatment, to help distinguish between individuals who are good or poor early responders to therapy. Subsequent therapy could then be de-escalated in PET-negative individuals (good responders) or escalated in those who are PET-positive (poor responders). It is currently unknown whether such response-adapted therapeutic strategies are of benefit to individuals in terms of overall and progression-free survival, and the incidence of long-term adverse events (AEs).