Schöder H et al. (2005) 2-[18F]Fluoro-2-deoxyglucose positron emission tomography for the detection of disease in patients with prostate-specific antigen relapse after radical prostatectomy. Clin Cancer Res 11: 4761–4769

2-[18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is useful in the detection of a variety of solid tumors, but the value of this imaging technique in prostate cancer is unproven. Image artefacts in the lower pelvis—caused by accumulation of excreted FDG tracer in the bladder—have been a significant problem in this setting. The recent development of newer, iterative image-reconstruction techniques, however, has allowed improved interpretation of FDG-PET images. In their recent study, Schöder and colleagues investigated the use of FDG-PET plus optimal image reconstruction in patients with biochemical recurrence following prostatectomy for prostate cancer.

This retrospective analysis included 91 patients, all of whom had undergone radical retropubic prostatectomy and had subsequently suffered prostate-specific antigen relapse (prostate-specific antigen >0.1 ng/ml in three consecutive measurements at least 2 weeks apart). Local and/or metastatic lesions were shown by FDG-PET in 31 of the patients. Comparison with bone scan, MRI and CT results showed three of the cases to probably be false positives; in addition, two further cases that were missed by FDG-PET, one of local recurrence and one of metastatic disease, were identified by other imaging devices. The remainder of the false-negative results by FDG-PET, however, were also negative using other imaging techniques.

The study showed that the probability of detecting recurrent disease by FDG-PET increased with rising PSA levels. Noting this fact, Schöder et al. suggest that this method might be appropriate only in those with PSA levels of over 2.4 ng/ml or a PSA doubling time of above 1.3 ng/ml/year.