en Radiation Biology Radiation Biology تحقيق بديع Original Research <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background:</span></span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">To investigate the dynamic changes in 18F-FDG PET/CT (18F)-derived metabolic parameters throughout the entire chemotherapy process for diffuse large B-cell lymphoma (DLBCL), and to analyze their clinical value in early diagnosis, curative effect evaluation, and prognosis stratification. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Materials and Methods: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">One hundred and sixty-five patients with suspected DLBCL admitted from April 2022 to May 2023 were included. 18F scans were performed before chemotherapy (baseline), after 3-4 courses of chemotherapy (interim), and 6-8 weeks following chemotherapy completion (post-therapy). SUVmax, SUVmean, and TLG were calculated by delineating the metabolic tumor volume (MTV). Therapeutic efficacy was evaluated using the Deauville 5-point scale. Patients were followed up for 2 years to record their survival outcomes. A combined diagnostic model was constructed using Logistic regression, with its predictive efficiency analyzed using ROC curves. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Results: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">Baseline SUVmax, SUVmean, MTV, and TLG were higher in DLBCL patients than in non-DLBCL cases (P<0.05). The combined model demonstrated an AUC of 0.972, with 93.15% sensitivity and 89.13% specificity. The interim metabolic parameters were highly correlated with Deauville scores. Higher SUVmax, MTV, and TLG levels were observed in the poor-efficacy group than in the good-efficacy group (P<0.05). Besides, the death group exhibited SUVmax, MTV, and TLG elevations compared to the survival group (P<0.05). The area under the ROC curve for the combined detection in predicting the prognostic mortality of DLBCL patients was 0.942 (P<0.001). </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Conclusion: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The temporal variations of metabolic parameters derived from 18F prove valuable for the early detection, therapeutic effect assessment, and prognostic prediction of DLBCL.</span></span></span></span></span></span></span></span></span></div> 18-F-FDG PET/CT, diffuse large b-cell lymphoma, metabolic parameters, prognosis. 729 734 http://ijrr.com/browse.php?a_code=A-10-1-1570&slc_lang=en&sid=1 X. Dong 7900319475328460034355 7900319475328460034355 No Department of Nuclear Medicine, Affiliated Hospital of Hebei University, Baoding, Hebei, China W. Ge 7900319475328460034356 7900319475328460034356 No Department of Radiology, Affiliated Hospital of Hebei University, Baoding, Hebei, China S. Li 7900319475328460034357 7900319475328460034357 No Department of Nuclear Medicine, Affiliated Hospital of Hebei University, Baoding, Hebei, China N. Feng hbmufengna@163.com 7900319475328460034358 7900319475328460034358 Yes Department of Radiology, Affiliated Hospital of Hebei University, Baoding, Hebei, China