Abstract:

INTRODUCTION: This study aims to disclose the frequency and clinical significance of incidental prostatic uptake during FDG PET imaging. METHODS: FDG PET images of 1839 male patients undergoing imaging for non-prostate and non-urinary bladder malignancy indications were retrospectively reviewed for the presence of incidental prostatic FDG uptake. Prostatic volume, calcification and the presence and pattern of FDG uptake were evaluated. Further follow-up prostatic evaluation results were comparatively assessed. RESULTS: Incidental prostatic FDG uptake was detected in 41 out of 1839 patients(2.22%). Biopsy was done in 14 patients(34,14%) on follow-up and disclosed prostatic adenocarcinoma in 3(7.31%), inflammation/prostatitis in 2 and findings compatible with BPH in 4 patients.The pattern of FDG uptake was diffuse in 12 and focal in 29 patients. Patients who were found to have adenocarcinoma on follow-up disclosed FDG uptake with a focal pattern at a peripheral location. No significant difference existed between patients with malignant or benign disease of the prostate with respect to either the SUVmax or the PSA levels; SUVmax levels were found to overlap in the two groups. DISCUSSION AND CONCLUSION: Incidental prostatic FDG uptake may be associated with prostate cancer, benign pathologies and even a normal prostate gland. Overlapping SUVmax levels in the benign and malignant pathologies make SUVmax level alone an inappropriate tool in the diagnosis of cancer. Further clinical investigation is warranted to disclose a probable prostatic malignancy in patients who display incidental prostatic FDG uptake on PET imaging employed for various other indications.

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