Fluorine-18-fluorodeoxyglucose positron emission tomography is useless forthe detection of local recurrence after radical prostatectomy

Objective: After radical retropubic prostatectomy a rise of the prostate-sp ecific antigen (PSA) indicates a local recurrent or metastatic disease. If the bone scan shows no apparent bone metastasis, morphological imaging meth ods like x-ray computed tomography, magnetic resonance imaging or transrect al ultrasound often cannot distinguish between postoperative scar and local recurrence. Therefore we investigated the feasibility of fluorine-18-fluor odeoxyglucose positron emission tomography (F-18 FDG PET) for metabolic cha racterization of prostatic cancer, especially for differentiation of scar o r recurrent prostate cancer after radical prostatectomy. Methods: Dynamic P ET with 370 MBq F-18 deoxyglucose (F-18 FDG) up to 60 min p.i. was performe d in 2 patients with biopsy-proven benign prostatic hyperplasia, in 11 pati ents with a histologically proven prostate cancer prior to radical retropub ic prostatectomy (RRP) and 7 patients with suspected local recurrence (with negative bone scan) after RRP prior to biopsy of anastomosis (3 local recu rrence, 4 postoperative scar). Results: Prostate cancer showed a very low F -18 FDG uptake. The placement of regions of interest was only possible by t he use of other imaging methods. There was not difference between the F-18 FDG uptake of benign prostate hyperplasia, prostate carcinoma, postoperativ e scar or local recurrence after radical prostatectomy. Conclusion: F-18 FD G seems not to be useful to distinguish between postoperative scar and loca l recurrence after radical prostatectomy.