ESMO 2014 Report: Joint Session ESMO-EANM – Impact of molecular imaging management of lymphoma

by Denys Wheatley: ESMO  Madrid September 2014.  Session Monday 29 September  11.00.  PET imaging – Potential, pitfalls, and future directions.  Two talks on Hodgkin (HL) and non-Hodgkin lymphoma (NHL) were given in this PET in this session were given by Martin Hutchings (UK) and Josee Zijlstra (The Netherlands). The first speaker described PET/CT as an accurate tool regarding the staging therapy and response assessment of Hodgkin disease. If risk stratification is done prior to therapy, a better assessment of the extent of the disease can be obtained, and early PET response is an improved means of predicting outcome. This can be after just one cycle of chemotherapy, but can be followed by interim stratification. There is a case now for PET/CT being used in relapsed and refractory disease. It remains a highly sensitive diagnostic tool, and has its use in trial design and the management of individual patients, but greater awareness of these roles is needed amongst HL oncologists.

Zijlstra sees an interim response to ¹⁸Fluorodeoxglucose (FDG)-PET of potential use in distinguishing non-responders from responder with NHL. Thus non-responders to therapy can be shifted earlier to other intervention modalities. It continues to be of value in post-treatment assessment of diffuse large B cell lymphoma (DLBCL). Criteria that help in the use of PET is coming through the fully established International Harmonization Project, with the clear distinction of positive versus negative with regard to the intensity of uptake of the trace molecule, i.e. in relation to end-of-treatment response. There is also the five-point Deauville Scale on visual interpretation of lymphomas, giving important means of interpreting metabolic status with respect to tumour and its sensitivity or resistance to chemotherapy. In terms of interim rather than early response in NHL, it was apparent that early was promising, and more work needs to be done on parameters of interim response to turn this into a better tool in future, for which there is a need for clinical trials.