Current importance of positron emission tomography in Hodgkin's lymphoma

F-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is increasingly being used during and after chemotherapy to modulate the intensity of therapy. This concept was evaluated by the German Hodgkin Study Group (GHSG) in the HD15 trial and recruitment in the multicenter trials of the GHSG HD16-HD18 trials is ongoing. In the HD15 trial patients with advanced stages and PET negative residual tissue (PR a parts per thousand yenaEuro parts per thousand 2.5 cm) were treated without radiation therapy. A comparable study question is being examined by the HD16 trial for early stages and by the HD17 trial for intermediate stages. In the HD18 trial the number of chemotherapy cycles is reduced for PET negative patients in the early interim PET/CT. Therapy stratification (with or without radiation therapy) based on PET/CT after 6 cycles of the BEACOPP(escalated) regimen for advanced stages of Hodgkin's lymphoma is the standard of care after the final analysis of the HD15 data was published. After a less intensive chemotherapy in the early and intermediated stages of Hodgkin's lymphoma radiation therapy is the standard of care outside clinical trials. The interpretation of data requires a longer observation period in the follow-up care. For final conclusions from the H10 trial of the European Organisation for Research and Treatment of Cancer (EORTC) for early and intermediate stages, it remains to be seen whether the slightly higher number of early relapses will be compensated by a lower rate of adverse events in the long-term follow-up (e.g., secondary neoplasms and cardiopulmonary toxicity) and whether the second line therapy is effective in cases of relapse.