Positron emission tomography at the end of first-line therapy and during follow-up in patients with Hodgkin lymphoma: a retrospective study

Background: Routine positron emission tomography (PET) in follow-up of Hodgkin lymphoma (HL) after treatment is still controversial. The aim of this retrospective study was to analyze the clinical impact of routine PET examination during the follow-up for relapse detection in PET-negative HL patients at the end of therapy. Patients and methods: PET scans were carried out in 113 HL patients at the end of therapy and during the follow-up either in regular intervals or in a suspected relapse. Median follow-up of the group was 34 months. Results: Overall 327 PET scans were evaluated in 113 patients (median three PET scans per patient). At the end of therapy, 94 (83.2%) patients were PET negative and 19 (16.8%) PET positive. Regular follow-up PET scans in 67 of 94 PET-negative patients correctly identified tumor in 6 of 155 PET scans (3.9%). In 27 of 94 patients with clinically suspected relapse, 5 of 27 PET scans (18.5%) confirmed tumor. Conclusions: Our analysis showed that there is no need for regular follow-up with PET scans in PET-negative patients at the end of therapy: the ratio of true-positive PET scans during the follow-up is low (3.9%). Positive PET at the end of therapy and during follow-up should be evaluated with caution.