TY - JOUR AR - RCO-2018-1-106 TI - The Correlation between Lymphoma Cell Size and PET-CT Metabolic Activity in Follicular Lymphomas AU - Alaa , Muslimani AU - Bor-Tau , Hung AU - Ching-yee , Oliver Wong AU - Govinda , Brahmanday AU - Ishmael , Jaiyesimi AU - James , Huang AU - Mohammad Muhsin , Chisti AU - Paul, Rigo AU - Pek-lan , Khong JO - Radiotherapy and Clinical Oncology PY - 2018 DA - Fri 15, Mar 2019 SN - 2674-2497 DO - http://dx.doi.org/10.31487/j.RCO.2018.01.006 UR - https://www.sciencerepository.org/the-correlation-between-lymphoma-cell-size-and-PET-CT-metabolic-activity-in-follicular-lymphomas_RCO-1-106 KW - Lymphoma, PET Tumor size SUV AB - The purpose of this study was to correlate the average lymphoma cell size and metabolic activity in follicular lymphoma (FL) by comparing to the pathological grading, in a cohort of FL subjects. Methods: 64 patients with FL were retrospectively studied. 44 cases were grade 1-2 (FL1-2) and 20 were grade 3 (FL3). The average tumor cell size was measured based on flow cytometric analysis of the relative forward scatters (FSC) of tumor cells relative to that of internal T-cells in the lymphoma tissue. The metabolic activity was measured using maximal standardized uptake value (SUV) of the involved lymph node by 18F-FDG PET– CT scan. The SUV was normalized to a glucose level of 100 mg/dl using the formula: SUV100 = SUV x {[100 mg/dl]/[Glc]}g where g = [-0.5] and [Glc] was the glucose level recorded at the time of PET scan. The lymphoma cell size (FSC) and metabolic activity (SUV100) was cross-tabbed and correlated using cut off values determined by discriminant analysis. Results: Average lymphoma cell size of FL3 was significantly (p < 0.0005) greater than that of FL1-2. There was significant correlation between lymphoma cell size (FSC) and metabolic activity (SUV100) (p = 0.021), suggesting the possibility of combining these two objective measurements to grade FL. Conclusions: The significant difference of average lymphoma cell size between FL3 and FL1-2 validate the utility of flow cytometry in grading FL. The significant correlation between cell size and metabolic activity suggests that metabolic activity can further serve as an independent criterion in grading.