PET in Hodgkin's lymphoma. Can positron emission tomography improve the therapy?

PET-negative patients after 2 cycles of chemotherapy (interim-PET) rarely develop a relapse. Thus, the negative prognostic value of interim-PET in therapy monitoring of Hodgkin's lymphoma is high. The next clinical step towards response-adapted therapy (therapy de-escalation) using interim-PET should be embedded in clinical trials and scientific evaluation. This increases the safety for the patients and PET should be evaluated by a second reader. After completion of chemotherapy the progression-free survival was 95% for PET-negative patients in partial remission, as shown in the HD15 trial of the German Hodgkin Study Group (GHSG). Thus, consolidation radiotherapy can be omitted in PET patients with residual tissue of >= 2.5 cm without increasing the risk for progression or early relapse as compared to patients in complete remission. The impact of this finding on the overall survival at 5 years must be awaited. However, such therapy consequences must always be oriented to the intensity of the preceding chemotherapy.