LAUSR

PurposeThis study investigated the correlative relationship between metabolic parameters estimated from dual time point 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG) positron emission tomography/computerized tomography (PET/CT) and the clinical tools predicting the outcome of a lymphoma. We also measured metabolic and volumetric alterations between early and delayed 18F-FDG PET/CT in patients with high grade lymphoma (HGL).MethodsThe samples were 122 lymph nodes and extralymphatic lesions from 26 patients diagnosed with HGL. All patients were applied to the International Prognostic Index (IPI), Ann Arbor stage, and revised IPI as clinical prognostic parameters. 18F-FDG dual time point PET/CT (DTPFP) consisted of an early scan 1 h after 18F-FDG injection and a delayed scan 2 h after the early scan. Based on an analysis of DTPFP, we estimated the standardized uptake value (SUV) of tumors from the early and delayed scans, retention index (RI) representing the percentage change between early and delayed SUV, and metabolic volume different index (MVDI) calculated using metabolic tumor volumes (MTV).ResultsRImax showed a multiple positive correlative relationship with stage and IPI in lesion-by-lesion analysis (p < 0.01). In the case of IPI, the high risk group exhibited higher RImax than the low risk group (p = 0.004). In the case of revised IPI, the RImax of the low risk group were significantly lower than the intermediate and high risk groups, respectively (p < 0.01). The MVDIs of the best outcome group were decreased in comparison to the moderate outcome group (p = 0.029). There was a significant negative correlative relationship between RImax and MVDI, and the inclinations for decreased MVDIs were slightly associated with increased RIs.ConclusionsRImax extracted from DTPFP had a significant relationship to extranodal involvement, staging, IPI, and revised IPI. MVDI showed significant negative correlation with RImax. Further large scale studies are warranted to support and extend these preliminary results.