The combination of 13N-ammonia and 18F-FDG whole-body PET/CT on the same day for diagnosis of advanced prostate cancer

Abstract

PurposeThe aim of the study was to evaluate the efficacy of 13N-ammonia and 18F-fluorodeoxyglucose (18F-FDG) PET performed on the same day in the detection of advanced prostate cancer (PC) and its metastases.Patients and methodsTwenty-six patients with high-risk PC [Gleason score 8–10 or prostate-specific antigen (PSA)>20 ng/ml or clinical tumor extension≥T2c] were recruited into the study. 13N-Ammonia and 18F-FDG PET/CT were performed on the same day (18F-FDG followed ammonia, with an interval of a minimum of 2 h). Lesions were interpreted as positive, negative, or equivocal. Patient-based and field-based performance characteristics for both imaging techniques were reported.ResultsThere was significant correlation between 13N-ammonia and 18F-FDG PET/CT in the detection of primary PC (κ=0.425, P=0.001) and no significant difference in sensitivity (60.2 vs. 54.5%) and specificity (100 vs. 83.3%). The maximum standard uptake values and corresponding target-to-background ratio values of the concordantly positive lesions in prostate glands in the two studies did not differ significantly (P=0.124 and 0.075, respectively). The sensitivity and specificity of PET imaging using 13N-ammonia for lymph node metastases were 77.5 and 96.3%, respectively, whereas the values were 75 and 44.4% using 18F-FDG. The two modalities were highly correlated with respect to the detection of lymph nodes and bone metastases.ConclusionThe concordance between the two imaging modalities suggests a clinical impact of 13N-ammonia PET/CT in advanced PC patients as well as of 18F-FDG. 13N-Ammonia is a useful PET tracer and a complement to 18F-FDG for detecting primary focus and distant metastases in PC. The combination of these two tracers on the same day can accurately detect advanced PC.

The Role of Magnetic Resonance Imaging and Positron Emission Tomography/Computed Tomography in the Primary Staging of Newly Diagnosed Prostate Cancer: A Systematic Review of the Literature

“…Three studies reported on other imaging modalities such as 18 FDG-PET/CT, 11C-acetate-PET/CT, or 13N-ammonia-PET/ CT and reported promising results [124,143,144]. Two studies assessed the use of FDG-PET/CT for primary staging.…”

“…Two studies assessed the use of FDG-PET/CT for primary staging. While FDG-PET/CT remained less useful for relatively welldifferentiated tumors, favorable sensitivity for FDG-PET/CT (90-100%) was observed in high-risk patients [124,144,145]. When compared with 13N-ammonia, both tracers had perfect sensitivity for the detection of bone metastases [144].…”

“…While FDG-PET/CT remained less useful for relatively welldifferentiated tumors, favorable sensitivity for FDG-PET/CT (90-100%) was observed in high-risk patients [124,144,145]. When compared with 13N-ammonia, both tracers had perfect sensitivity for the detection of bone metastases [144]. One study reported favorable sensitivity and specificity for 11C-acetate-PET/CT versus bone scintigraphy in the detection of bone metastases (100% vs 69% and 98% vs 94%, respectively) [143].…”

Differentiation of suprasellar meningiomas from non-functioning pituitary macroadenomas by 18F-FDG and 13N-Ammonia PET/CT

“…Sometimes SSMs can break through the diaphragma sellae and grow into the pituitary fossa making it difficult to differentiate them from NFPMAs extending anteriorly and superiorly on usual morphological imagings [7,18] . PET/CT as one of the most important molecular imaging modalities has been confirmed to be satisfied in the accurate prediction of brain tumors and widely used in clinical practice with various tracers [19][20][21] .…”

PET Metabolic Biomarkers for Cancer

“… 23 On the other hand, tumors with low metabolic rates, such as the mucinous adenocarcinomas, or weak glucose avidity, such as some prostate cancers, can be associated with equivocal or negative scans. 24 , 25 Also, it is impossible to discriminate between the glucose oxidative pathway and anaerobic consumption when using 18 F-FDG because it is not metabolized beyond phosphorylation. 11 C-glucose could be used as an alternative to follow the anaerobic and oxidative pathways, but PET imaging only detects the presence of radioactivity and not the type of carrier; therefore, it cannot differentiate between the native radiotracer and its metabolites.…”