Prognostic value of 18F-FDG PET/CT and C-MYC gene rearrangement on chemotherapy in patients with diffuse large B-cell lymphoma

Abstract

Objective To evaluate the prognostic value of the maximum standardized uptake value decrease proportion (ΔSUVmax%) on 18F-fluorodeoxyglucose (FDG) PET/CT imaging and C-MYC gene in diffuse large B cell lymphoma (DLBCL), and to find the optimal time of PET/CT imaging. Methods From September 2010 to February 2016, 171 patients (87 males, 84 females, average age: (50.66±2.56) years) with pathologically confirmed DLBCL were analyzed. 18F-FDG PET/CT were performed before and after different courses of chemotherapy (60 patients in early phase which means 1 and 2 courses; 55 patients in medium phase, 3 and 4 courses; 56 patients in late phase, 5 and 6 courses). The region of interest (ROI) was drawn and the ΔSUVmax% was calculated. Patients were evaluated with Deauville 5-point scale. Fluorescence in situ hybridization (FISH) was employed to detect C-MYC gene. Patients were followed up for 6-71 months, and progression-free survival (PFS) was calculated. χ2 test, one-way analysis of variance, Kaplan-Meier analysis and Spearman correlation analysis were used to analyze the data. Results There were 42 C-MYC gene rearrangement of 171 DLBCL patients. Age, Ann Arbor stage, international prognostic index (IPI) score, serum lactate dehydrogenase (LDH) level and therapeutic response were different between patients with C-MYC gene rearrangement and those without rearrangement (χ2: 6.139-98.339, all P 0.05). Conclusion ΔSUVmax% in the different phases of chemotherapy and C-MYC gene rearrangement have better values for predicting the prognosis of DLBCL, and 18F-FDG PET/CT imaging should be performed between 1 course and 4 courses of chemotherapy. Key words: Lymphoma, large B cell, diffuse; Prognosis; Gene rearrangement; Genes, myc; Positron-emission tomography; Tomography, X-ray computed; Deoxyglucose