Performance of FDG PET/CT at initial diagnosis in a rare lymphoma: nodular lymphocyte-predominant Hodgkin lymphoma.

Abstract

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare Hodgkin lymphoma distinguished from classical Hodgkin lymphoma (cHL) by the nature of the neoplastic cells which express B-cell markers. We wanted to determine the diagnostic performance of FDG PET/CT in initial assessment and its therapeutic impact on staging. We retrospectively studied a population of 35 patients with NLPHL (8 previously treated for NLHPL, 27 untreated). All patients underwent an initial staging by pretherapeutic FDG PET/CT. The impact on initial stage or relapse stage was assessed by an independent physician. In a per-patient analysis, the sensitivity of the pretherapeutic FDG PET/CT was 100%. In a per-site analysis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of pretherapeutic FDG PET/CT were 100%, 99%, 97%, 100% and 99%, respectively. Pretherapeutic FDG PET/CT led to a change in the initial stage/relapse stage in 12 of the 35 patients (34%). In contrast to previous results established without FDG PET/CT, 20% of patient had osteomedullary lesions. Pretherapeutic FDG PET/CT has excellent performance for initial staging or relapse staging of NLPHL.