AIM: Patients with suspected recurrence of prostate cancer undergoing 18Fluoromethylcholine (18FCH) PET/CT were retrospectively evaluated to investigate the influence of hormonal therapy (HT) in 18FCH uptake.
METHODS: 18FCH PET/CT was performed in 102 surgically treated patients with suspected recurrence (PSA increase > 0.2 ng/ml) of prostate cancer, divided in two groups: under HT (n. 54) and without HT (n.48) at the time of PET scanning. PET/CT was carried out by an integrated system (Biograph 6, Siemens), intravenously administering 4.1 MBq/kg of 18FCH to each patient; images were acquired 60 minutes after.
RESULTS: In the total patients 66 resulted true positive (TP), 9 false positive (FP), 5 false negative (FN) and 22 true negative (TN), sensititivity of 18FCH PET/CT was 93%, specificity 71%, accuracy 86%, positive predictive value (PPV) 88%, negative predictive value (NPV) 81%. In the 54 patients under HT 38 were TP, 6 FP, 3 FN and 7 TN, sensitivity was 93%, specificity 54%, accuracy 83%, PPV 86% and NPV was 70%. In the 48 patients without HT 28 were TP, 3 FP, 2 FN and 15 TN, sensitivity was 93%, specificity 83%, accuracy 90%, PPV 90% and NPV 88%. Chi--square test showed that sensitivity, accuracy and PPV did not differ among patients with and without HT, while specificity and NPV were significantly lower (p < 0.001) in HT treated patients.
CONCLUSION: Sensitivity, accuracy and PPV were similar in patients with and without HT. Specificity and NPV were reduced in patients under HT, but further data are necessary to support if this reduction is casual or related to therapy and it could be confirmed in a larger series of patients.
Palumbo B, Sivolella S, Palumbo I, Buresta T, Radicchia V, Fravolini ML, Ferretti F, Bellavita R, Mearini L, Scialpi M, Aristei C, Pelliccia G. Are you the author?
Section of Nuclear Medicine and Medical Physics, Department of Surgical and Biomedical Sciences, University of Perugia, Italy.
Reference: Q J Nucl Med Mol Imaging. 2014 Jul 14. Epub ahead of print.