Early interim 18F-FDG PET in Hodgkin's lymphoma: evaluation on 304 patients.

PURPOSE: The use of early (interim) PET restaging during first-line therapy of Hodgkin's lymphoma (HL) in clinical practice has considerably increased because of its ability to provide early recognition of treatment failure allowing patients to be transferred to more intensive treatment regimens. METHODS: Between June 1997 and June 2009, 304 patients with newly diagnosed HL (147 early stage and 157 advanced stage) were treated with the ABVD regimen at two Italian institutions. Patients underwent PET staging and restaging at baseline, after two cycles of therapy and at the end of the treatment. RESULTS: Of the 304 patients, 53 showed a positive interim PET scan and of these only 13 (24.5%) achieved continuous complete remission (CCR), whereas 251 patients showed a negative PET scan and of these 231 (92%) achieved CCR. Comparison between interim PET-positive and interim PET-negative patients indicated a significant association between PET findings and 9-year progression-free survival and 9-year overall survival, with a median follow-up of 31 months. Among the early-stage patients, 19 had a positive interim PET scan and only 4 (21%) achieved CCR; among the 128 patients with a negative interim PET scan, 122 (97.6%) achieved CCR. Among the advanced-stage patients, 34 showed a persistently positive PET scan with only 9 (26.4%) achieving CCR, whereas 123 showed a negative interim PET scan with 109 (88.6%) achieving CCR. CONCLUSION: Our results demonstrate the role of an early PET scan as a significant step forward in the management of patients with early-stage or advanced-stage HL.