[18F]-fluorodeoxyglucose positron emission tomography combined with computed tomography detection of asymptomatic late pulmonary toxicity in patients with non-Hodgkin lymphoma treated with rituximab-containing chemotherapy.

Rituximab is a chimeric anti-CD20 monoclonal antibody widely used in the treatment of B-cell non-Hodgkin lymphomas (NHL). Most adverse effects are due to infusion-related reactions, and severe respiratory complications are rare. We retrospectively reviewed clinical data and serial imaging studies of five patients with NHL treated with rituximab-containing chemotherapy who developed new pulmonary abnormalities on routine follow-up FDG-PET/CT imaging. None of the patients had pulmonary lymphoma or other pulmonary disease before therapy and all remained asymptomatic during follow-up. New pulmonary interstitial FDG-uptake was detected on follow-up FDG-PET/CT between 1 and 3 months post-treatment, preceded computed tomography abnormalities in one case, and persisted for several months. FDG uptake was linear, subpleural with maximum Standardized uptake value (SUV) from 2.0 to 5.84. Rituximab-containing chemotherapy for NHL may be associated with asymptomatic late pulmonary toxicity characterised by a distinct FDG uptake pattern. Awareness of this finding is important and should not be confused with lymphoma.