Israel Medical Association Journal

Background: Pulmonary infiltrates (PIs) detected in patients with non-Hodgkin lymphoma (NHL) may present a diagnostic challenge due to their wide differential diagnosis, including infection, pulmonary lymphoma and immunochemotherapy-associated pulmonary toxicity.

Objectives: To characterize therapy-associated PIs by positron emission tomography/computed tomography (PET/CT) imaging.

Methods: We conducted a historical analysis of fluorodeoxyglucose-PET/CT (¹⁸F-FDG-PET/CT) PIs in NHL patients treated with combined immunochemotherapy including rituximab. Incidence of PIs, radiological features, patients’ characteristics, underlying NHL type, rituximab/chemotherapy dosing schedules, and symptoms were recorded. Therapy-associated PIs were defined as new or worsening PIs appearing after treatment onset, without evidence of active pulmonary lymphoma or infection.

Results: Among 80 patients who met the pre-specified criteria, therapy-associated PIs were identified in 17 (21%), 6 of whom had accompanying symptoms. Increased FDG uptake was observed in nine, and PI resolution in six. The incidence of PIs was higher in females and in patients with aggressive lymphoma, at advanced stages, and in those who had received treatment consisting of a combination of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone every 14 days (R-CHOP-14).

Conclusions: This characterization of therapy-associated PIs may support the clinician managing NHL patients. Further prospective studies are needed to establish the role of each therapeutic component and the natural history of this phenomenon.

Patients with a compromised immune system suffer a wide variety of insults. Interstitial lung changes are one of the most common and serious complications in this group of patients. The morbidity rate reaches 50% and up to 90% if endotracheal intubation and mechanical ventilation are necessary. Opportunistic and bacterial infections are common causes of pulmonary infiltrates and must be distinguished from other conditions such as drug reactions, volume overload, pulmonary hemorrhage, and malignant diseases. Accurate and prompt diagnosis of potentially treatable causes can be life-saving. Non-invasive diagnostic methods for evaluation are often of little value, and an invasive procedure - such as bronchoalveolar lavage, transbronchial biopsy or even open lung biopsy - is therefore performed to obtain a histologic diagnosis. Yet, even when a specific diagnosis is made it may not improve the patient’s survival. Numerous textbook and review articles have focused on the management of this condition. The present review attempts to provide a comprehensive and systematic picture of current knowledge and an integrated approach to these challenging patients.