Search

PURPOSE: Previous studies have shown that the positive detection rate of [(11)C]choline positron emission tomography/computed tomography (PET/CT) depends on prostate-specific antigen (PSA) plasma levels. This study compared PSA levels and PSA doubling time (PSADT) to predict [(11)C]choline PET/CT findings. METHODS: PSADT was retrospectively calculated in 170 prostate cancer (PCa) patients with biochemical failure after radical prostatectomy who underwent [(11)C]choline PET/CT. PSADT was calculated as PSADT = ln2/m, where m is the slope of the linear regression line of the natural log of PSA values. At least three PSA measurements were used (median: 4; range: 3-16), separated by at least 3 months, each with a minimum increase of 0.20 ng/ml. PET/CT findings were validated using criteria based on histological analysis and clinical and imaging data. Statistical analysis was performed using the t test, chi-square test, analysis of variance and binary logistic regression. Regression-based coefficients were used to develop a nomogram predicting the probability of positive [(11)C]choline PET/CT and 200 bootstrap resamples were used for internal validation. RESULTS: The median PSA was 1.25 ng/ml (range: 0.23-48.6 ng/ml), and the median PSADT was 7.0 months (range: 0.97-45.3 months). [(11)C]choline PET/CT was positive in 75 of 170 patients (44%). PET/CT findings were validated using histological criteria (11%) and clinical and imaging criteria (89%). The overall accuracy of [(11)C]choline PET/CT was 88%. Multivariate logistic regression showed that high PSA and short PSADT were significant (p < 0.05) predictors of positive [(11)C]choline PET/CT [PSA: odds ratio (OR) = 1.43; 95% confidence interval (CI): 1.15-1.78; PSADT: OR = 1.12; 95% CI: 1.04-1.21]. The percentage of patients with positive [(11)C]choline PET/CT was 27% for PSADT >6 months, 61% for PSADT between 3 and 6 months and 81% for PSADT 6 months to 52% for PSADT 6 months (p < 0.05). A nomogram based on age, PSA, PSADT, time to trigger PSA, Gleason score, pathological stage and androgen deprivation therapy demonstrated bootstrap-corrected predictive accuracy of 81%. CONCLUSION: Like PSA, PSADT is an independent predictor of [(11)C]choline PET/CT. [(11)C]choline PET/CT is very sensitive to PCa tumour growth, as reflected by PSA kinetics. PSADT should be taken into account by physicians when referring PCa patients for [(11)C]choline PET/CT.

PURPOSE: Detection of recurrence in prostate cancer patients with biochemical failure after radical prostatectomy by [(11)C]choline PET/CT depends on the prostate-specific antigen (PSA) level. The role of other clinical and pathological variables has not been explored. METHODS: A total of 2,124 prostate cancer patients referred to our Institution for [(11)C]choline PET/CT from December 2004 to January 2007 for restaging of disease were retrospectively considered for this study. Inclusion criteria were: previous treatment by radical prostatectomy, and biochemical failure, defined as at least two consecutive PSA measurements of >0.2 ng/ml. These criteria were met for 358 patients. Binary logistic analysis was used to investigate the predictive factors of [(11)C]choline PET/CT. PET/CT findings were validated using criteria based on histological analysis, and follow-up clinical and imaging data. Receiver operating characteristic (ROC) analysis was used to assess the performance of [(11)C]choline PET/CT in relation to PSA levels. RESULTS: The mean PSA level was 3.77 +/- 6.94 ng/ml (range 0.23-45 ng/ml; median 1.27 ng/ml). PET/CT was positive for recurrence in 161 of 358 patients (45%). On an anatomical region basis, [(11)C]choline pathological uptake was observed in lymph nodes (107/161 patients, 66%), prostatectomy bed (55/161 patients, 34%), and in the skeleton (46/161 patients, 29%). PET/CT findings were validated using histological criteria (46/358, 13%), and follow-up clinical and imaging criteria (312/358, 87%). Sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy were, respectively, 85%, 93%, 91%, 87%, and 89%. In multivariate analysis, high PSA levels, advanced pathological stage, previous biochemical failure and older age were significantly (P < 0.05) associated with an increased risk of positive PET/CT findings. The percentage of positive scans was 19% in those with a PSA level between 0.2 and 1 ng/ml, 46% in those with a PSA level between 1 and 3 ng/ml, and 82% in those with a PSA level higher than 3 ng/ml. ROC analysis showed that PET/CT-positive and PET/CT-negative patients could be best distinguished using a PSA cut-off value of 1.4 ng/ml. CONCLUSIONS: In addition to PSA levels, pathological stage, previous biochemical failure and age should be considered by physicians when referring prostate cancer patients with biochemical failure after radical prostatectomy to [(11)C]choline PET/CT.

PURPOSE: We assessed the value of [(11)C]choline positron emission tomography/computerized tomography in patients with prostate cancer in whom biochemical failure developed after radical prostatectomy but who showed no disease evidence on conventional imaging. MATERIALS AND METHODS: Considered for this study were 2,124 patients treated with radical prostatectomy who underwent [(11)C]choline positron emission tomography/computerized tomography to restage disease between December 2004 and January 2007. Study inclusion criteria were 1) previous radical prostatectomy and pelvic lymph node dissection, 2) increasing prostate specific antigen beyond 0.2 ng/ml after radical prostatectomy, 3) no lymph node disease at radical prostatectomy, 4) no evidence of metastatic disease on conventional imaging, 5) no androgen deprivation therapy and 6) no adjuvant or salvage radiotherapy. These criteria were satisfied in 109 of the 2,124 patients (5%). RESULTS: Median prostate specific antigen at imaging was 0.81 ng/ml (range 0.22 to 16.76 ml). Imaging suggested local recurrence in 4 patients (4%) and pelvic lymph node disease in 8 (7%). Scans were positive in 5%, 15% and 28% of patients with prostate specific antigen less than 1, between 1 and 2, and greater than 2 ng/ml, respectively (p

Purpose The accuracy of positron emission tomography (PET)/CT with [11C]choline for the detection of prostate cancer is not well established. We assessed the dependence of [11C]choline maximum standardized uptake values (SUVmax) in the prostate gland on cell malignancy, prostate-specific antigen (PSA) levels, Gleason score, tumour stage and anti-androgenic hormonal therapy. Methods In this prospective study, PET/CT with [11C]choline was performed in 19 prostate cancer patients who subsequently underwent prostatectomy with histologic sextant analysis (group A) and in six prostate cancer patients before and after anti-androgenic hormonal therapy (bicalutamide 150 mg/day; median treatment of 4 months; group B). Results In group A, based on a sextant analysis with a [11C]choline SUVmax cutoff of 2.5 (as derived from a receiver-operating characteristic analysis), PET/CT showed sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 72, 43, 64, 51 and 60%, respectively. In the patient-by-patient analysis, no significant correlation was detected between SUVmax and PSA levels, Gleason score or pathological stage. On the contrary, a significant (P