Assessment of alteration in liver 18F–FDG uptake due to steatosis in lymphoma patients and its impact on the Deauville score

Thibault Salomon (1) , Catherine Nganoa (1) , Anne-Claire Gac (2) , Christophe Fruchart (2) , Gandhi Damaj (2) , Nicolas Aide (1, 3) , Charline Lasnon (3, 4)

1 Service de médecine nucléaire [CHU Caen]
2 IHBN - Institut d'Hématologie de Basse-Normandie
3 ANTICIPE - Unité de recherche interdisciplinaire pour la prévention et le traitement des cancers
4 UNICANCER/CRLC - Centre Régional de Lutte contre le Cancer François Baclesse [Caen]

AIM: Our aim was (1) to evaluate the prevalence of steatosis in lymphoma patients and its evolution during treatment; (2) to evaluate the impact of hepatic steatosis on 18F-FDG liver uptake; and (3) to study how hepatic steatosis affects the Deauville score (DS) for discriminating between responders and non-responders. METHODS: Over a 1-year period, 358 PET scans from 227 patients [122 diffuse large B cell lymphoma (DLBCL), 57 Hodgkin lymphoma (HL) and 48 Follicular lymphoma (FL)] referred for baseline (n = 143), interim (n = 79) and end-of-treatment (EoT, n = 136) PET scans were reviewed. Steatosis was diagnosed on the unenhanced CT part of PET/CT examinations using a cut-off value of 42 Hounsfield units (HU). EARL-compliant SULmax were recorded on the liver and the tumour target lesion. DS were then computed. RESULTS: Prevalence of steatosis at baseline, interim and EoT PET was 15/143 (10.5%), 6/79 (7.6%) and 16/136 (11.8%), respectively (p = 0.62).Ten out of 27 steatotic patients (37.0%) displayed a steatotic liver on all examinations. Six patients (22.2%) had a disappearance of hepatic steatosis during their time-course of treatment. Only one patient developed steatosis during his course of treatment. Liver SULmax values were significantly lower in the steatosis versus non-steatotic groups of patients for interim (1.66 ± 0.36 versus 2.15 ± 0.27) and EoT (1.67 ± 0.29 versus 2.17 ± 0.30) PET. CT density was found to be an independent factor that correlated with liver SULmax, while BMI, blood glucose level and the type of chemotherapy regimen were not. Using a method based on this correlation to correct liver SULmax, all DS4 steatotic patients on interim (n = 1) and EoT (n = 2) PET moved to DS3. CONCLUSIONS: Steatosis is actually a theoretical but not practical issue in most patients but should be recognised and corrected in appropriate cases, namely, for those patients scored DS4 with a percentage difference between the target lesion and the liver background lower than 30%.

Mots clés: Deauville score; FDG; Liver; Lymphoma; PET; Steatosis

Domaines: Santé publique et épidémiologie; Cancer

Thibault Salomon, Catherine Nganoa, Anne-Claire Gac, Christophe Fruchart, Gandhi Damaj, et al.. Assessment of alteration in liver 18F–FDG uptake due to steatosis in lymphoma patients and its impact on the Deauville score. European Journal of Nuclear Medicine and Molecular Imaging, 2018, 45 (6), pp.941 - 950. ⟨10.1007/s00259-017-3914-y⟩. ⟨inserm-01856020⟩