Differentiation of HIV-associated lymphoma from HIV-reactive adenopathy using quantitative FDG-PET and symmetry

Excerpt

In this issue of the European Journal of Nuclear Medicine and Molecular Imaging, Mhlanga et al. [1] address the important challenge of differentiating between HIV-reactive lymphadenopathy and HIV-associated lymphoma using FDG PET/CT. What is more interesting about this study is the fact they rigorously assessed the quantitative PET metabolic metrics to distinguish these entities. The investigators evaluated nodal and extranodal visual qualitative metabolic scores, SUL-Max, SUL-Peak, CT nodal size, and PERCIST 1.0 threshold-based TLG and metabolic tumour volume (MTV), in 19 patients with biopsy-proven untreated lymphoma (16 with large B-cell lymphoma, 3 with Hodgkin lymphoma) and 22 patients with reactive adenopathy. The results of this study demonstrated that quantitative PET metrics performed significantly better than qualitative visual scores, although qualitative symmetry assessment was valuable. Both quantitative PET metrics and qualitative assessments of symmetry of uptake were also more robust than CT nodal size assessments. The investigators are therefore to be congratulated on achieving their aim and developing a potential practical approach, with the limitations also being interesting for future prospective studies. …