Significance of incidental focal uptake in prostate on 18-fluoro-2-deoxyglucose positron emission tomography CT images

Abstract

To evaluate the clinical significance of incidental focal prostate fluorodeoxyglucose (FDG) uptake, we reviewed 18-F-FDG positron emission tomography (PET)/CT scans from 2003 to 2007 and selected cases with focal FDG uptake in prostate. Cases of known prostate cancer were excluded. The maximum standardised uptake value (SUV(max)), site (central or peripheral) and pattern (discrete or ill-defined) of FDG uptake, calcification (present or absent) and prostate volume (<30 or ≥30 cc) were recorded. The PET/CT findings were correlated with serum prostate-specific antigen (PSA) levels, imaging studies, clinical follow-up and biopsy. Of a total of 5119 cases, 63 (1.2%) demonstrated focal FDG uptake in prostate. Eight cases were lost to follow-up. Among the 55 cases with follow-up, malignancy was confirmed by biopsy in 3 (5.4%). The three malignant cases had SUV(max) values of 3.3, 3.6 and 2.3, and all were noted in the peripheral portion of prostate; two of these cases had a discrete FDG uptake pattern, none had calcification corresponding to the FDG uptake area and one had a prostatic volume greater than 30 cc. The mean SUV(max) of 52 benign cases was 3.2 ± 1.7 and focal FDG uptake was noted in the peripheral portion in 34 (65%), 20 (38%) cases showed a discrete FDG uptake pattern, 35 (67%) were accompanied by calcification and 32 (62%) had a prostatic volume greater than 30 cc. The majority of cases demonstrating focal FDG uptake in prostate were benign and no PET/CT finding could reliably differentiate benign from malignant lesions; however, when discrete focal FDG uptake without coincidental calcification is seen, particularly in the peripheral zone of the prostate, further clinical evaluation is recommended.

Incidental Abnormal FDG Uptake in the Prostate on 18-fluoro-2-Deoxyglucose Positron Emission Tomography-Computed Tomography Scans

“…Several studies have addressed the incidental detection rate of prostate cancer (Han et al, 2010;Hwang et al, 2013). The incidence of abnormal focal hypermetabolism in the prostate gland in two previous studies was 1.2-1.5%.…”

Incidental fleurodeoxyglucose uptake in the prostate

“…The retrospective observational study included 5119 FDG PET CTs obtained as part of clinical workup for cancer, excluding those done for staging or restaging prostate cancer, and as a part of a health screening programme. Of the 5119 patients in this study, only 3 were confirmed as having FDG-avid prostate cancers [1].Eun Ji Han's study adds to the literature by showing that even if a prostate lesion is FDG avid, it is unlikely to be due to cancer. 53 of 55 patients with focal FDG uptake were considered to have benign lesions.…”

“…The retrospective observational study included 5119 FDG PET CTs obtained as part of clinical workup for cancer, excluding those done for staging or restaging prostate cancer, and as a part of a health screening programme. Of the 5119 patients in this study, only 3 were confirmed as having FDG-avid prostate cancers [1].…”

“…The commentary considers the management of incidental prostate FDG uptake on the basis of the available evidence. The study on the incidence of prostate cancer in patients with incidental fleurodeoxyglucose (FDG) foci in the prostate has provoked this commentary [1]. It is clearly established that, in general, prostate adenocarcinomas show no or mild FDG uptake [2][3][4][5].…”

Granulomatous Prostatitis After Intravesical Bacillus Calmette-Guérin Instillation Therapy: A Potential Cause of Incidental F-18 FDG Uptake in the Prostate Gland on F-18 FDG PET/CT in Patients with Bladder Cancer

“…Incidental uptake in the prostate gland is discovered in approximately 1.2-1.5 % of patients on F-18 FDG PET/CT [1,2]. This uptake can represent prostate malignancy, but many of these findings indicate benign lesions such as benign prostatic hyperplasia (BPH) or prostatitis [3].…”