Standardized uptake value for (18)F-fluorodeoxyglucose is correlated with a high International Prognostic Index and the presence of extranodal involvement in patients with diffuse large B-cell lymphoma.

UNLABELLED The aim of this study was to evaluate whether the maximum standardized uptake value (SUVmax) of (18)F-fluorodeoxyglucose (FDG) correlates with the International Prognostic Index (IPI) and the presence of extranodal involvement in patients with Diffuse Large B-Cell Lymphoma (DLBCL). MATERIAL AND METHODS 77 patients (age: 57.2±18.5, 40F, 37M) with DLBCL who underwent FDG PET/CT for initial staging were included. SUVmax of the predominant lesions were compared to Ann Arbor stage, IPI scores, the presence of extranodal involvement and the number extranodal sites. RESULTS PET/CT detected nodal (n:25) and extranodal involvement (n:52) in all the patients. In 27 patients, extranodal disease could only be detected by PET. SUVmax of the predominant lesion in patients with extranodal disease was significantly higher than that of the patients who had only nodal disease (25±12 vs. 15.3±10 respectively, p=0.001). SUVmax significantly correlated with IPI scores; the average SUVmax was significantly correlated with the IPI: Mean SUVmax of the predominant lesion was 13.9±9.5 in patients with low risk (IPI=0-1), 14.2±8.8 in low-intermediate risk group (IPI=2) whereas 26.6±9.5 in high-intermediate risk group (IPI=3) and 25±13.6 in high risk group patients (IPI=4-5) (p=0.002). SUVmax was not correlated with clinical stage, the number of extranodal sites and serum LDH levels. CONCLUSION FDG uptake correlates with IPI and the presence of extranodal involvement in DLBCL. PET is a powerful method to detect extranodal disease in DLBCL. The correlation of SUVmax with these prognostic factors may highlight the importance of pretreatment FDG uptake as a metabolic marker of poor prognosis for patients with DLBCL.