d-SUV assessment for I-PET assessment. The Groupe d'Etude des Lymphomes de l'Adulte (GELA) have led the effort to use a semiquantitative method to determine whether an I-PET scan should be considered positive or negative. In their opinion, the utility of I-PET is suspect based upon the heterogeneity of the visual criteria used and suboptimal interobserver reproducibility when interpreting PET-CT images on the basis of entirely visual criteria. Instead, their research strategy is based upon the differences of SUVs (dSUV) from the initial scan to the interim scan.