Background. Positron emission tomography with fluorodeoxyglucose offers the possibility to differentiate between lymphoma and nonmalignant tissue. The aim of this retrospective study was a comparison between PET and conventional imaging methods before and after therapy - during the follow-up of Hodgkin’s lymphoma. Methods and Results. The group of 94 patients with HL underwent 180 PET examinations. PET was performed in 53 patients during initial staging of lymphoma. 119 PET studies were undertaken after therapy during the follow-up. Eight patients underwent PET examination for suspected relapse or progression of HL. Findings were verified by a follow-up in all patients and by histology in selected cases. PET and conventional imaging methods were positive in 42 of 53 (79 %) patients in initial stages. The stage of the disease was changed in 7 patients (13.2 %) according to PET. False negative findings were recorded in three cases and false positive in one case. Sensitivity of PET was higher compared to conventional imaging methods (92 % vs 87 %) in initial staging. PET and conventional imaging methods were identical in 94.9 % of cases during the follow-up (77.3 % negative and 17.6 % positive findings). Sensitivity of PET during the follow-up after therapy was higher compared to conventional imaging methods (99.1 % vs 95.7 %). PET was positive in all eight cases in relapse/progression of HL and conventional imaging methods were positive in only seven of eight cases. Conclusions. PET is a more sensitivemethod in initial staging, during follow-up and in suspected progression/relapse of HL than conventional imaging methods and it should be included into routine examination methods of HL.

        Key words: positron emission tomography, Hodgkin’s lymphoma, residual tumor.