asco@alo33:164911 JSONTXT

Background: The Lugano Classification incorporating FDG-PETCT in the staging and response assessment of lymphomas as published JCO 2014 . We previously reported that there as some non-negligible discrepancy beteen the clinical stage assessed by FDGPETCT and that assessed by the conventional evaluation ESMO Asia 2015 . We expanded the number of the patients in addition to the previous study to make our data more reliable. Methods: Patients pts ho ere initially histopathologically diagnosed as having DLBCL at our institution from 2010 to 2014 ere included. The clinical stage using FDG-PETCT as compared to that assessed by the conventional evaluation based on CT, esophagogastroduodenal endoscopy EGD and bone marro BM examination. Results: A total of 163 pts ere identified as subjects of this retrospective analysis ith a median age of 65 years range; 23-86 . 18 pts 11 percent resulted in upstaging through conventional evaluation plus FDG-PETCT; 2 from stage I to II, 5 from I to IV, 2 from II to III, 7 from II to IV, and 2 from III to IV. 3 pts 2 percent resulted in donstaging; 1 from stage II to I, and 2 from IV to III. Gastrointestinal tract GIT lesions contributed to upstaging most, hich accounted for 44 percent of upstaged pts. Hoever, compared ith EGD, FDG-PETCT seems to be less accurate in detecting gastric lesions. Postulating EGD as standard examination, false-negative rate of FDG-PETCT in gastric lesions as 31 percent Table 1 . FDG-PETCT positive colon lesions in 6 pts ere found to be false-positive by colonoscopy as they ere adenocarcinomaadenoma. Bone or BM lesions ere more frequently detected by FDG-PETCT. BM examination detected 17 pts 10 percent ith BM lesions, hile FDG-PETCT detected 30 pts 24 percent . Hoever, 3 pts 2 percent of BM lesions ent undetected by FDG-PETCT. Conclusions: Our data suggests that FDG-PETCT cannot completely take the place of conventional staging evaluation for DLBCL mainly because of its lo accuracy in detecting GIT lesions, although FDG-PETCT is useful in the staging of DLBCL. Therefore, e recommend EGD as one of the routine staging procedures of DLBCL. ltth class=border-bottom align-left rospan=2 ltth class=border-bottom-broken colspan=2 EGDx0026;Biopsy+x2212;FDG-PETCT+183x2212;8126,J Clin Oncol 34, 2016 suppl; abstr e19057 ,Publication Only: