STAGING FDG‐AVIDITY IN EXTRANODAL MARGINAL ZONE LYMPHOMA (EMZL) BY DISEASE LOCATION

Introduction: Fluorodeoxyglucose (FDG)-PET/CT is the standard imaging modality to assess initial tumor burden and response therapy in lymphoma. FDG-avidity EMZL remains unclear with variability by extranodal locations. Thus, current Lugano staging suggested use CT scans EMZL. Recent data challenging this suggestion. we evaluated using a large MZL database. Methods: We assessed University of Miami database searching for patients PET/CT. Currently, includes 715 578 (80.8%) EMZL; 152 (26.3%) have PET/CT were analyzed. Patients high-grade transformation at diagnosis excluded. In >1 site, each location was counted independently providing total 187 PET/CTs reviewed expert radiologists ascertain not surrounding tissue avidity, specific attention ocular GI locations; if available (n = 15), retrieved from reports. involvement defined as focal uptake above normal physiologic activity. considered FDG-avid disease SUVmax ≥2 calculated ratios between lymphoma mediastinal blood pool (BP index) liver background (Liver index). Results: This cohort (2/2016–1/2023) Most women 88, 58%), median age 62 years (range 33–83), Hispanics 77, 51%). LDH largely 126, 83%) most having early-stage 98, 64%). Among locations, common gastric 33,17.6%), 31, 16.6%), lung 30, 16%), skin soft 16, 8.6%, each), salivary gland 13, 7%), airways 11, 5.9%), breast 9, 4.8%). locations (SUVmax ≥2) (100%), (93.8%), (93.3%), (93.5%, conjunctiva 75%), (90.9%), bone (83.3%), GI-nongastric (80%), (72.7%), (44.4%). Skin (93.8%) non-FDG avid (Table 1). Median size lesions 2.4cm (range, 0.7–17.4). All 22 multiple mucosal sites demonstrated least one 17 across all sites. about FDG avidity 150), BP index Liver ≥1 detected 79.3% 71.5%, respectively. Both indexes failed identify (Figure 1A,B). The research funded by: Sylvester Comprehensive Cancer Center National Institute (NCI) core grant P30CA240139 Keywords: non-Hodgkin lymphoma, indolent PET-CT No conflicts interests pertinent abstract.