Efficiency of whole-body 18F-FDG PET CT in detecting the cause of rising serum AFP level in post-therapeutic follow-up for HCC patients.

PURPOSE: The goal of this study was to assess the value of whole-body 18F-FDG PET/CT in detecting the cause of rising serum alpha-fetoprotein (AFP) level after the treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: 18F-FDG PET/CT studies were performed for 100 patients (76 men and 24 women), ranged in age from 40 to 76 years who had underwent either surgical resection or interventional therapy for HCC, but were subsequently noted to have rising AFP serum level on routine follow-up examinations. The 18F-FDG PET/CT results were correlated with histological findings or radiological and clinical follow-up. RESULTS: According to patient-based analysis, 18F-FDG PET/CT demonstrated 74 true-positives, four false-negatives, 16 true-negative, and 6 false-positive results, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 95%, 72.7%, 92.5%, 80%, and 90%, respectively. According to Lesion-based analysis, 18F-FDG PET/CT demonstrated 202 true-positive lesions, 8 false-negatives, and 16 true-negative and 6 false-positive results, with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 72.7%, 97%, 80%, and 95.6%, respectively. CONCLUSION: 18F-FDG PET/CT is a valuable imaging tool investigating patients who have a rising serum AFP level after HCC treatment. It accurately detects residual or recurrent tumor as well as extrahepatic metastasis.

68Ga-PSMA-11 PET/CT in newly diagnosed prostate cancer: diagnostic sensitivity and interobserver agreement.

PURPOSE: To determine the diagnostic sensitivity and interobserver agreement of Gallium 68-prostate-specific membrane antigen positron emission tomography/computed tomography (68Ga-PSMA-11 PET/CT) imaging for diagnosis and staging of patients with newly diagnosed prostate cancer (PC). MATERIALS AND METHODS: One hundred and seventy-three men (mean age, 68 ± 7.7 years; range 46-84 years) with newly diagnosed, untreated PC were enrolled in this prospective study between January 2017 and August 2018. All patients underwent a 68Ga-PSMA-11 PET/CT examination. For each patient, we determined the disease stage, the Gleason score, and the maximum standardized uptake value (SUVmax) for primary prostatic tumor and extraprostatic metastases. The diagnostic sensitivity and interobserver agreement of 68Ga-PSMA-11 PET/CT for diagnosis and staging of PC were established by histopathology as the reference standard. RESULTS: 68Ga-PSMA-11 PET/CT examinations were interpreted as positive for PC in 166 of 173 patients (101 patients had primary prostatic tumor only, two patients had extraprostatic metastases only and 63 patients had combined lesions). The sensitivity of 68Ga-PSMA-11 PET/CT examination in the diagnosis of PC was 96%. 68Ga-PSMA-11 PET/CT produced a significant change of stage in 28.6% patients with an upstage in 17.9% patients and a downstage in 10.7% patients. The interobserver agreements were almost good to perfect (k = 0.63-0.89) for visual image interpretation, SUVmax measurement, and tumor staging. CONCLUSION: 68Ga-PSMA-11 PET/CT is a valuable tool with high diagnostic sensitivity (96%) and high reproducibility for diagnosis and staging of patients with newly diagnosed PC.