Abstract:ObjectiveTo investigate the application of 18 fluoro-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) metabolic parameters in mucosa-associated lymphoid tissue(MALT) lymphoma. Methods The clinical data of 38 patients diagnosed with MALT lymphoma between May 2016 and June 2020 at Hospital of Nantong University were retrospectively analyzed; 22 of these patients had unresected local lesions before the baseline PET/CT was completed, and tumor metabolic indicators were taken, including tumor metabolic volume (MTV), total glycolysis (TLG), mean standardized uptake value (SUVmean), and peak standardized uptake value (SUVpeak). The PET/CT Deauvile-5ps (DS) score of 16 patients at mid-treatment was refined. The correlation between PET/CT tumor metabolic parameters and clinical characteristics, progression-free survival(PFS) and overall survival(OS) of MALT lymphoma and their predictive value was assessed. Results Among the 22 patients, MTV was significantly different in LDH and primary site subgroups; TLG was significantly different in tumor stage, LDH, and primary site subgroups; SUVmean was significantly different among different subgroups of tumor stage, β2 microglobulin, Ki-67, and primary site respectively （P<0.05）. The SUVpeak also differed significantly between different subgroups for tumor stage, β2 microglobulin, Ki-67 and primary site （P<0.05）. MTV was significantly different in the presence/absence of B symptoms and LDH; TLG was significantly different in B symptoms, IPI score, β2 microglobulin, LDH and site of disease; and TLG was significantly positively correlated with MTV （P<0.05）. SUVmean was significantly correlated with IPI score and disease site （P<0.05）. There was a significant correlation between SUVpeak and disease location （P<0.05）. MTV, TLG, SUVmean, and SUVpeak were significantly correlated with OS, all with statistically significant differences （P<0.05）. And only TLG was significantly associated with PFS （P<0.05）. In this study, we also obtained clinically relevant information on mid-chemotherapy review PET/CT in 16 patients, and the results of survival analysis showed that PFS was significantly prolonged in patients with negative review PET/CT than in positive patients （P<0.05）. Conclusions PET/CT tumor metabolic parameters were correlated with clincial feature, PFS and OS in patients with MALT lymphoma, which could assist in clinical diagnosis, disease staging and prognosis evaluation.