Positron emission tomography with 11C-acetate and 18F-FDG in prostate cancer patients

Abstract

Visualisation of primary prostate cancer, its relapse and its metastases is a clinically relevant problem despite the availability of state-of-the-art methods such as CT, MRI, transrectal ultrasound and fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET). The aim of this study was to evaluate the efficacy of carbon-11 acetate and (18)F-FDG PET in the detection of prostate cancer and its metastases. Twenty-five patients were investigated during the follow-up of primary prostate cancer, suspected relapse or metastatic disease using (11)C-acetate PET; 15 of these patients were additionally investigated using (18)F-FDG PET. Fourteen patients were receiving anti-androgen treatment at the time of the investigation. Lesions were detected in 20/24 (83%) patients using (11)C-acetate PET and in 10/15 (75%) patients using (18)F-FDG PET. Based on the results of both PET scans, one patient was diagnosed with recurrent lung cancer. Median (18)F-FDG uptake exceeded that of (11)C-acetate in distant metastases (SUV =3.2 vs 2.3). However, in local recurrence and in regional lymph node metastases, (11)C-acetate uptake (median SUVs =2.9 and 3.8, respectively) was higher than that of (18)F-FDG (median SUVs =1.0 and 1.1, respectively). A positive correlation was observed between serum PSA level and both (11)C-acetate uptake and (18)F-FDG uptake. (11)C-acetate seems more useful than (18)F-FDG in the detection of local recurrences and regional lymph node metastases. (18)F-FDG, however, appears to be more accurate in visualising distant metastases. There may be a role for combined (11)C-acetate/(18)F-FDG PET in the follow-up of patients with prostate cancer and persisting or increasing PSA.

Incidental diagnosis of a PSA-negative prostate cancer by 18FDG PET/CT in a patient with hypopharyngeal cancer

“…This has to be emphasized as these biochemical findings are sometimes unspecific and may also be found in patients with nonmalignant diseases of the prostate gland such as benign hyperplasia, prostatitis or even in healthy individuals. [2][3][4][5][6]9,[12][13][14][15][16][17][18] Even the described slight increase of the PSA level from 1.68 to 2.21 ng/ml after 2 years, which consecutively decreased to 1.9 ng/ml at the time of surgery, or a potential rise of the percent-free PSA in relation to total PSA, would not have required a prostate biopsy in any case as, despite the described rise of the PSA, PSA levels were still within and even not at the upper limit (4.0 ng/ml) of the normal range. In addition, estimation of percent-free PSA is also prone to variations between malignant and benign masses of the prostate.…”

“…12 Mainly 11 C-/ 18 F-choline and 11 C-/ 18 F-acetate seem to be of value for the named indications and superior to FDG-PET, especially in the diagnosis of primary PC. 6,12,[24][25][26][27][28][29][30] However, as in some studies, a differentiation between benign hyperplasia from cancerous lesions of the prostate gland was not possible with for example 18F-fluorocholine PET/CT imaging, all of these tracers still need clinical evaluation with regard to their diagnostic value in PC. 26 …”

“…MRI and CT are often unable to accurately stage the extent of prostatic malignancies. [5][6][7][8] On the other hand, the use of FDG-PET, introduced as a promising alternative, has become one of the most important and innovative clinical applications in oncology. 9 Even with persisting high costs, FDG-PET is almost routinely used in the clinical management of certain cancer patients.…”

“…11 Consequently, several previously published studies failed to show a beneficial impact of FDG-PET, except in the detection and localization of distant metastases in hormone-refractory PC. 2,5,6,9,[12][13][14][15] Additionally, even the recently introduced PET/CT technique, adding morphological information to metabolic data of FDG-PET, failed to improve the diagnostic value of FDG-PET imaging for PC in a small series of patients. 15 Data regarding new radiotracers for the diagnosis of PC, for example 11 C-choline, seem to have a beneficial impact on the diagnostic value as compared to FDG-PET, but data are still discussed controversially and, as of yet, failed to show a significant correlation between the uptake of 11 C-choline and tumor grade or Gleason score.…”

Is there a role for positron emission tomography imaging in the early evaluation of prostate cancer relapse?

“…Thus, rather than simply replacing a tracer with another, a multitracer approach may be needed to fully exploit the potential of PET imaging in the setting of biochemical failure. 23,56 …”