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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

AIMS AND BACKGROUND: Evaluation of the metabolic response to radiotherapy in nonsmall cell lung cancer patients is commonly performed about three months after the end of radiotherapy. The aim of the present study was to assess with positron emission tomography/computed tomography (PET/CT) and [18F]fluorodeoxyglucose changes in glucose metabolism during and after radiotherapy in non-small cell lung cancer patients. METHODS AND STUDY DESIGN: In 6 patients, PET/CT scans with [18F]fluorodeoxyglucose were performed before (PET0), during (PET1; at a median of 14 days before the end of radiotherapy) and after the end of radiotherapy (PET2 and PET3, at a median of 28 and 93 days, respectively). The metabolic response was scored according to visual and semiquantitative criteria. RESULTS: Standardize maximum uptake at PET1 (7.9 +/- 4.8), PET2 (5.1 +/- 4.1) and PET3 (2.7 +/- 3.1) were all significantly (P < 0.05; ANOVA repeated measures) lower than at PET0 (16.1 +/- 10.1). Standardized maximum uptake at PET1 was significantly higher than at both PET2 and PET3. There were no significant differences in SUV(max) between PET2 and PET3. PET3 identified 4 complete and 2 partial metabolic responses, whereas PET1 identified 6 partial metabolic responses. Radiotherapy-induced increased [l8F]fluorodeoxyglucose uptake could be visually distinguished from tumor uptake based on PET/CT integration and was less frequent at PET1 (n = 2) than at PET3 (n = 6). CONCLUSION: In non-small cell lung cancer, radiotherapy induces a progressive decrease in glucose metabolism that is greater 3 months after the end of treatment but can be detected during the treatment itself. Glucose avid, radiotherapy-induced inflammation is more evident after the end of radiotherapy than during radiotherapy and does not preclude the interpretation of [18F]fluorodeoxyglucose images, particularly when using PET/CT.

PURPOSE:: Positron emission tomography/computed tomography (PET/CT) with C-11 choline has been used for staging, restaging, and follow-up of various tumors, whereas its role for imaging meningiomas has only been preliminarily explored. The aim of this study was to compare C-11 choline and F-18 fluorodeoxyglucose (F-18 FDG) uptake in meningiomas and relate these findings to the histopathological analysis. METHODS:: Two sequential three-dimensional PET/CT scans with 370 MBq (10 mCi) of C-11 choline and 370 MBq (10 mCi) of F-18 FDG were performed 2 hours apart in 7 patients with histologically confirmed meningiomas. Five patients had WHO grade I and 2 had WHO grade II meningioma. For each scan, two-dimensional regions of interest were drawn on tumor boundaries and on the contralateral side on CT images and copied to the corresponding PET images. SUVmax and tumor-to-background ratio were calculated. RESULTS:: Relative to the contralateral side, C-11 choline uptake was increased in all meningiomas, whereas F-18 FDG uptake was decreased in 6 patients and increased in 1 of the 2 patients with grade II meningiomas. In the whole group, SUVmax of C-11 choline and F-18 FDG were 3.6 +/- 1.3 and 5.7 +/- 1.3, respectively. The tumor-to-background ratio for C-11 choline was much higher than that for F-18 FDG (5.3 +/- 0.8 vs. 0.9 +/- 0.2, respectively) (P < 0.001). The uptake of C-11 choline was higher in patients with grade II than in grade I meningiomas. CONCLUSIONS:: These preliminary results suggest that C-11 choline may better image meningiomas in comparison with F-18 FDG. Clinical applications of C-11 choline PET/CT for grading and follow-up of meningiomas need to be assessed in further studies.

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

Purpose The aims of this study were to compare CT with PET/CT results in patients with suspected ovarian cancer recurrence and to assess the impact of the PET/CT findings on their clinical management. Methods Thirty-two consecutive patients with suspected ovarian cancer recurrence were retrospectively included in the study. Abdominal contrast-enhanced CT and PET/CT with [18F]FDG, in addition to conventional follow-up, were performed in all 32 patients. After the comparison between CT and PET/CT results, based on clinical reports, changes in the clinical management of patients (intermodality changes) due to PET/CT information were analysed. Results Twenty of the 32 patients were positive at CT (62.5%) versus 29 (90.6%) at PET/CT. Intermodality changes in management, i.e. use of a different treatment modality, after PET/CT examination were indicated in 14/32 (44%) patients. In particular, before PET/CT study, the planned management was as follows: wait-and-see in 7/32 (22%), further instrumental examinations in 4/32 (12%), chemotherapy in 10/32 (31%), diagnostic surgical treatment in 6/32 (19%) and surgical treatment in the remaining 5/32 (16%). After PET/CT study, wait-and-see was indicated in 1/32 (3%), further instrumental examinations in 7/32 (22%), chemotherapy in 16/32 (50%), diagnostic surgical treatment in 2/32 (6%) and surgical treatment in the remaining 6/32 (19%). Conclusion Integrated PET/CT could detect tumour relapse in a higher percentage of patients than could CT. A change in the clinical management was observed in 44% of cases when PET/CT information was added to conventional follow-up findings.