The Evaluation Of Initial Staging, Treatment Response And Prognosis By Double Tracer PET/CT Imaging In Vivo In Diffuse Large B Cell Lymphoma

[Objective]PET/CT is currently the only technology of anatomical features with metabolicfunction and receptor imaging. It has the advantages of high sensitivity, highspecificity and functional imaging. But the common tracer of¹⁸F-FDG has its ownlimitations. Application of the new tracer will to be further study. The evaluationof PET/CT for diagnosis of lymphoma requires further research. This study focuson the evaluation of initial staging, treatment response and prognosis by doubletracer PET/CT (¹⁸F-FDG PET/CT and¹⁸F-FLT PET/CT) imaging in vivo indiffuse large B cell lymphoma, which provide data for clinical applications.[Methods]In this study,67patients with biopsy confirmed DLBCL were rolled, all of themdetected by double tracer PET/CT and CT within1week after diagnosis.Compared with normal tissues and lesions distribution of double tracer, to assessthe value of initial staging by double tracer PET/CT. After2-4cycles and withinsix months after the first-line treatment, midtreatment and endtreatment doubletracer PET/CT were performed to assess the value of curative effect. Patients witha median of18months follow-up, multivariate analysis with pathological type,staging, IPI score, midtreatment PET/CT and other factors on the prognosis value.[Results]a)¹⁸F-FLT and¹⁸F-FDG distribution in the organization are complementary.The average SUVmax of two tracer have significantly different in pallium,alba, bone and liver. And in other organizations the average SUVmax of twotracer were similar. b) The lesions of DLBCL detected by double tracer PET/CT. The top3percentage lesions of the lymphatic system were Neck, supraclavicular fossa,occipital and preauricular lymph nodes （30%）, Abdominal cavity andretroperitoneal lymph nodes （24%）, Cavitas pelvis lymph nodes andMediastinal lymph nodes （11%）. The top3percentage lesions of theextranodal organ were bone （34%）, intestines （9%）, lung and muscle （8%）.T/MB value of lesions detected by two tracer PET/CT provide data for clinicalapplication.c) The sensitivity, specificity, NPV, PPV, false positive rate, false negative rateand accuracy of¹⁸F-FDG-PET/CT and¹⁸F-FLT-PET/CT for lesions in DLBCLwere all significantly better than CT （p<0.05）. The comparion of sensitivity,specificity, PPV, false positive rate, false negative rate and accuracy of¹⁸F-FDG-PET/CT and¹⁸F-FLT-PET/CT for lesions in DLBCL were similar. Whilethe NPV of¹⁸F-FDG-PET/CT was significantly better than¹⁸F-FLT-PET/CT（p<0.05）, it maybe related to the high metabolic of¹⁸F-FLT in bone and easilybe missed.d) Both of¹⁸F-FDG-PET/CT and¹⁸F-FLT-PET/CT can accurate assess theefficacy of therapy and no significant difference.e) According multivariate analysis, pathological type, staging and midtreatment¹⁸F-FDG PET/CT were independence prognosis factors.f) Endtreatment PET/CT （within six months after the first-line treatment） canfind early relapse, some of patients were benefit from it.[Conclusion]Double tracer PET/CT can accurate assessment of staging, treatmentresponse and prognosis in DLBCL patients. The two tracer are complementaryand provide more valuable informations to adaption treatment stategy.