Rania Refaat

Diagnostic performance of 18 F-FDG PET/CT and whole-body MRI before and early after treatment of multiple myeloma: a prospective comparative study

AbstractObjectiveTo determine the diagnostic accuracy of WB-MRI and 18F-FDG PET/CT in detecting infiltration pattern, disease activity, and response to treatment in patients with multiple myeloma (MM).Materials and methodsFifty-six patients with confirmed MM were included in the present study for pre-treatment evaluation. Among these individuals, 22 patients were available for the post-treatment evaluation of response to therapy. All patients were imaged with both WB-MRI and 18F-FDG PET/CT. All radiographic findings of infiltration pattern, disease activity, and response to therapy were compared. The diagnostic performance of both modalities was estimated using bone marrow aspirate and biopsy as the reference test.ResultsFor detection of active myelomatous tissue at diagnosis, WB-MRI achieved higher sensitivity (94%) than 18F-FDG PET/CT (75%) (p = 0.0039), whereas both modalities achieved the same specificity (80%). For detection of residual myelomatous tissue after treatment, 18F-FDG PET/CT achieved higher specificity (86%) than WB-MRI (43%) (p = 0.0081), whereas both modalities achieved the same sensitivity (75%).ConclusionWB-MRI is more sensitive than 18F-FDG PET/CT in the diagnosis of MM before treatment; however, 18F-FDG PET/CT is more specific than WB-MRI in detecting residual involvement in treated patients.

Efficacy of contrast-enhanced FDG PET/CT in patients awaiting liver transplantation with rising alpha-fetoprotein after bridge therapy of hepatocellular carcinoma

ObjectiveTo assess the diagnostic accuracy and illustrate positive findings of contrast-enhanced fluorine-18 fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) image in patients awaiting liver transplantation (LT) with rising alpha-fetoprotein (AFP) after bridge therapy of hepatocellular carcinoma (HCC).Materials and methodsThis prospective study included 100 patients who were waiting for LT and who previously underwent locoregional therapy (LRT) of HCC. These patients had rising AFP levels on a routine follow-up examination awaiting LT. All patients underwent a contrast-enhanced 18F-FDG PET/CT examination. We calculated for each patient the maximum standardised uptake value (SUVmax) of the tumour and the ratio of the tumoral SUVmax to the normal-liver SUVmax. The diagnostic accuracy and positive contrast-enhanced findings of 18F-FDG PET/CT were established by histopathology and clinical and imaging follow-up as the reference standards.ResultsContrast-enhanced 18F-FDG PET/CT detected tumour relapse in 78 patients (13 patients had intrahepatic lesions, 10 patients had extrahepatic metastases and 55 patients with combined lesions). The sensitivity, specificity and accuracy values of contrast-enhanced 18F-FDG PET/CT examination in the detection of HCC recurrence were 92.8%, 94.1% and 93%, respectively. A significant correlation was found between the AFP level and SUVmax ratio (r = 0.2283; p = 0.0224). The best threshold for 18F-FDG PET positivity was >1.21.ConclusionContrast-enhanced 18F-FDG PET/CT is a valuable tool for the detection of intrahepatic HCC recurrence or extrahepatic metastasis following rising AFP levels after LRT of HCC, and should be incorporated during routine workup awaiting LT.Key Points•18F-FDG PET/CT is a valuable tool for the detection of HCC recurrence•18F-FDG PET/CT should be incorporated during routine workup awaiting liver transplantation•Significant correlation was found between AFP level and SUVmax ratio•The best threshold for18F-FDG PET positivity was >1.21• The ideal cut-off value for AFP was >202