We performed a work-up study of cancer patients with incidentally found uncharacterized prostatic fluorine-18-fluorodeoxyglucose (F-FDG) uptake in F-FDG PET/CT results. Then, we evaluated the clinical significance of the incidental prostate F-FDG uptake (IPU) in nonmalignant prostate tissues.
Overall, 51 men agreed to a physical prostate examination and an expressed prostatic secretion (EPS) test within 2 weeks after torso F-FDG PET/CT scans. We then reviewed the F-FDG PET/CT scans of the enrolled patients and evaluated the relationship between the F-FDG PET/CT, prostate-specific antigen, and prostatic laboratory findings.
The pathological diagnosis of five men indicated the presence of prostate cancer, and of the remaining 46 men, 27 cases showed IPU in the F-FDG PET/CT whereas 19 did not. The characteristics of the enrolled patients were as follows: mean age of 61.15±13.79 years (range: 30-83 years), maximum standardized uptake value of 2.64±1.33 (range: 1.2-7.1), and prostate-specific antigen of 3.10±3.50 ng/ml (range: 0.16-13.55 ng/ml). Ten of the 27 (37%) patients with IPU in the PET/CT scan showed bacterial infections in their prostate. A multivariate analysis indicated that the bacterial presence in the EPS increased the risk of IPU (adjusted odds ratio: 9.167; P=0.019).
Bacterial presence in the prostate tends to increase the likelihood of IPU in F-FDG PET/CT scans. Therefore, men with incidental prostate F-FDG uptake should be considered for a possible prostate infection in addition to a concomitant malignancy.
Nuclear medicine communications. 2017 Apr 05 [Epub ahead of print]
Gil Ho Lee, Jai Hyuen Lee
Departments of aUrology bNuclear Medicine, Dankook University College of Medicine, Cheonan, South Korea.