Background: In Hodgkin's disease accurate restaging is important to assess treatment results and may eventually provide a basis for further therapeutic strategies. A typical dilemma after treatment of Hodgkin's disease with radiographically persistent lymphoma is the differentiation between sterilized residual mass and viable tumor. Positron emission tomography (PET) has been described as a reliable tool to identify active lymphoma. Aim of the present study was to assess the accuracy and clinical relevance of PET for treatment control and in the situation of a suspected relapse of Hodgkin's disease.
Patients and methods: 63 patients (32 men, 31 women, mean age 41.5 years) with Hodgkin's disease were investigated with FDG-PET. In 51 patients 63 PET studies were performed as a treatment control (group 1) after primary therapy. 17 patients (5 of whom preexamined in group 1) underwent 18 PET scans for confirmation of suspected relapse (group 2). PET was performed with a dedicated whole-body ring scanner. In a retrospective analysis, all FDG-PET scans were compared with conventional imaging methods and related to the final diagnosis obtained by histology and/or clinical follow-up (mean 22.4 months).
Results: Group 1: FDG-PET showed an accuracy of 91%, whereas the accuracy of conventional imaging was 62%. Group 2: The accuracy for PET was 83% and 56% for conventional imaging.
Conclusion: The present data suggest that PET is a sensitive and reliable tool for detection of involved areas of active Hodgkin's disease. The accuracy of PET for restaging purpose seems to be superior than conventional imaging.