18F-FDG PET/CT imaging in the diagnosis of druginduced lung disease and pulmonary infection in lymphoma

Abstract

Objective: Lymphoma is a hematological disease with high prevalence. Multi-cycle chemotherapy (CHT) or local radiotherapy is applied usually; however, adverse events have been reported, such as drug-induced lung disease (DILD). Positron emission tomography/computed tomography (PET/CT) is often used to evaluate the lesion, treatment effect, and prognosis of lymphoma. We investigated DILD and pulmonary infection (PI) after multi-cycle CHT in lymphoma patients, to identify DILD and PI, provide guidance for later treatment for them. Methods: In all, 677 patients diagnosed with lymphoma and who underwent CHT were included. These patients underwent 18fluorodeoxyglucose (18F-FDG) PET/CT before and after CHT at Shandong Cancer Hospital (affiliated with Shandong University) between April 2015 and November 2019. Fifty patients developed DILD, 41 patients had lung infections; lesion characteristics were analyzed based on clinical characteristics, laboratory examinations, and PET/CT imaging. Results: Among the 677 lymphoma patients, there were 50 cases of DILD, with an incidence rate of 7.4%. PET/CT showed an elevated 18fluorodeoxyglucose uptake lung background, septal thickening and reticulation, multiple ground glass-like shadows, and grid-shaped blur shadows, which were more common in the lung periphery and under the pleura. The maximum standardized uptake value in the lung was 2.45 0.52. Pulmonary infections occurred in 41 patients, and the maximum standardized uptake value was 4.05 1.42. Age, sex, CHT cycle, Ann-Arbor stage, and lymphocyte levels were not significantly different between DILD and PI patients. Leukocyte and neutrophils showed significant differences; the PI patients had increased laboratory indexes of leukocyte and neutrophils. The mean number of CHT cycles was 4 cycles for DILD and PI. Conclusions: PET/CT imaging has high sensitivity and detection rates for primary and metastatic lymphoma lesions. DILD mostly occurs in the middle and late stages of CHT. Laboratory tests and PET/CT can evaluate the lesions and treatment effects, and provide guidance for subsequent treatment plans for patients. Abbreviations: 18F-FDG = 18Fluorodeoxyglucose, ABVD = doxorubicin (Adriamycin), bleomycin, vinblastine, and dacarbazine, CHT = chemotherapy, CT = computed tomography, DILD = drug-induced lung disease, HL = Hodgkin lymphoma, HRCT = highresolution computed tomography, NHL = non-Hodgkin lymphoma, PET/CT = positron emission tomography/computed tomography, PI = pulmonary infection, R-CDOP = rituximab, pegylated liposomal doxorubicin, cyclophosphamide, vincristine, and prednisone, R-CHOP = rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, SUR-BP = standardized uptake ratio-blood pool, SUVmax = the maximum standardized uptake value, SUVmean = mean standardized uptake value.