[18F]choline positron emission tomography in prostate cancer patients with biochemical recurrence after radical prostatectomy: influence of antiandrogen therapy – a preliminary study

Trigger pSA predicting recurrence from positive choline PET/CT with prostate cancer after initial treatment

Purpose

To assess the relationship between the diagnostic accuracy of Choline positron emission tomography/computed tomography (PET/CT) and the trigger prostate-specific antigen (PSA) level in patients with a biochemical recurrence of prostate cancer.

Materials and Methods

A meta-analysis was conducted to synthesize data across multiple studies.

Results

The pooled sensitivity and specificity of choline PET/CT were 82% (95% Confidence Interval (CI):80-84%) and 92% (95%CI: 90-93%), respectively. The pooled sensitivity and specificity of ¹⁸F-choline PET/CT were 81% (95%CI: 78-84%) and 90% (95%CI: 85-93%), respectively. The pooled sensitivity and specificity of ¹¹C-choline PET/CT were 83% (95% CI: 80-86%) and 92% (95% CI: 90-94%), respectively. The pooled detection rate of ¹⁸F-choline PET/CT and ¹¹C-choline PET/CT were 58% (95% CI: 48-68%) and 58% (95%CI: 49-68%), respectively.

Conclusions

Trigger PSA is an important risk factor for positive findings of Choline PET/CT and the detection rate of Choline PET/CT for recurrent prostate cancer increased in parallel with raises in PSA-values. Choline PET/CT got higher detection rate while the trigger PSA > 2ng/ml.

11C- or 18F-Choline PET/CT for Imaging Evaluation of Biochemical Recurrence of Prostate Cancer

Recurrence of prostate cancer is suspected when an increase in the prostate-specific antigen level is detected after radical treatment; the recurrence could be local relapse, distant relapse, or both. Differentiation between the two patterns of relapse is critical for choosing the proper treatment strategy. Choline PET/CT could be of help in discriminating patients with local, lymph node, and bone recurrences, thus having an impact on patient management.

Imaging of Prostate Cancer Using 18F-Choline PET/Computed Tomography

¹⁸F-fluorocholine (FCH) PET/computed tomography (CT) is a valuable imaging modality in prostate cancer disease. Probably, its main role is restaging of patients with biochemical recurrence after radical prostatectomy or external beam radiotherapy. ¹⁸F-FCH PET/CT is strengthening its position in the initial staging, biopsy target definition, radiotherapy planning, and therapy monitoring. Gleason score and prostate-specific antigen value, doubling time, and velocity can influence positivity of ¹⁸F-FCH PET/CT. The influence of androgen deprivation therapy on choline uptake is not precisely clarified. Collaboration between nuclear medicine physicians, radiologists, urologists, oncologists, and radiotherapists is crucial to help patients with prostate cancer disease.

Clinical Utility of Gallium-68 PSMA PET/CT Scan for Prostate Cancer

BACKGROUND

Prostate cancer is biologically and clinically a heterogeneous disease that makes imaging evaluation challenging. One of the important challenges in this cancer is to detect recurrent disease. Biochemical response using Prostate Specific Antigen (PSA) and Imaging using several PET tracers have poor sensitivity and specificity. Therefore, we analyse the role of Ga68-PSMA (Prostate Specific Membrane Antigen) imaging in prostate cancer, which is a new PET tracer.

METHODS

In this study, we evaluated PET scans of 262 patients with diagnosis of prostate cancer. These patients were scanned using Ga68-PSMA for either staging or response evaluation.

RESULTS

336 PSMA scans were performed. Ga68-PSMA scan resulted in the detection of extra-prostatic disease in 53.2% of cases when done at baseline before commencing any treatment. The sensitivity of Ga68-PSMA at baseline with histopathological diagnosis was 95% with 95% CI ranging from 86% to 98%. The positive predictive value was high at 98% with 95% CI ranging from 91% to 99%. In 26 (10%) patients who had surgical castration, Ga68-PSMA scan was able to detect disease progression / castration resistance in 100% of cases. The outcome of castration-resistant prostate cancer was compared with other cases where castration was not done. In those who did not undergo castration, there was a significantly better response by hormone therapy (p = 0.03) and radiotherapy (p = 0.01) on Ga68-PSMA. The sensitivity of Ga68-PSMA response with biochemical response was 66.7% with 95% CI ranging between 46 %- 82.7%. Ga68-PSMA response did not correlate with biochemical response.

CONCLUSION

Ga68-PSMA has good sensitivity for diagnosis, staging, restaging, evaluation of therapy response and prognostication in prostate cancer.

The ability of 18F-choline PET/CT to identify local recurrence of prostate cancer

PURPOSE

To determine when 18F-choline PET/CT can truly identify local recurrence of prostate cancer.

METHODS

1031 patients from 3 European centers underwent (18)F-choline PET/CT (FCH PET/CT) for recurrent disease; 131 subjects (12.7%) showed a positive FCH uptake in the prostatic gland or prostatic fossa. Median age was 72 years (range 48-87 years), and the median PSA level at the time of FCH PET/CT scan was 4.41 ng/mL (0.22-18.13 ng/mL). 45 patients (34.4%) had a Gleason score (GS) >7, and the residual subjects had a GS ≤ 7. The assessment of true or false-positive FCH PET/CT findings was made by magnetic resonance imaging (n = 34) and/or biopsy in 75/131 cases. A χ (2) test and a Z Kolmogorov-Smirnov test were used to assess the correlation between clinical variables (age, PSA, GS, type of therapy) and FCH PET/CT findings.

RESULTS

FCH PET/CT resulted truly positive (TP) for recurrent disease in the prostatic gland/fossa in 59/75 patients (79%) and falsely positive (FP) in 16 subjects (21%). The median value of PSA at the time of FCH PET/CT scan was higher in TP as compared to FP, although not statistically significant (4.76 vs. 3.04 ng/mL p > 0.05). Similarly, median age, GS categories, and the type of therapy were similar between the two groups (p > 0.05). However, when matching GS categories and PSA values, we found that the number of patients with TP findings were higher in the case of a PSA > 2 ng/mL, independently from the GS (ranging between 74% and 92%). Conversely, FP rate ranged between 50% and 65% in patients with a PSA ≤ 2 ng/mL, especially in the case of GS ≤ 7, whereas FP was around 25% in those with a GS >7 and PSA > 2 ng/mL.

CONCLUSIONS

FCH PET/CT has a limited role in evaluation of prostatic gland/fossa recurrence, due to the physiological biodistribution of the radiopharmaceutical agent. However, in 70-90% of patients with a PSA >2 ng/mL, independently from GS, a focal FCH uptake is compatible with a true local recurrence.

Acquisition with (11)C-choline and (18)F-fluorocholine PET/CT for patients with biochemical recurrence of prostate cancer: a systematic review and meta-analysis

The objective of the systematic review and meta-analysis was to evaluate whether the choice between two radiotracers, (11)C-choline ((11)C-cho) and (18)F-fluorocholine ((18)F-FCH) for PET/CT, and different acquisition protocols contributed to detect metastases for patients with biochemical recurrence of prostate cancer after radical prostatectomy or radiotherapy. We searched in January 2016 in Pubmed and Embase for articles that had used radiolabeled choline PET/CT in restaging. The meta-analysis evaluated technical and clinical aspects. Across 18 articles 1 219 of 2 213 patients (54.9 %) had a positive radiolabeled PET/CT image. Mean of the mean/median restaging PSA levels was 3.6 ± 2.7 ng/mL (range 0.5-10.7 ng/mL). Six articles with (11)C-cho PET/CT had a radiation activity of 561 ± 122 MBq and it was 293 ± 47 MBq in 12 articles with (18)F-FCH PET/CT. The difference was significant (P = 0.007, t test). Uptake time was 5 min in articles with (11)C-cho PET/CT and it was 29 ± 24 min in articles with (18)F-FCH PET/CT. The difference was significant (P = 0.02, t test). Thereby the detection rates of metastatic sites in articles with (11)C-cho (30 ± 5 %) and (18)F-FCH (39 ± 5 %) did not differ significantly (P = 0.26, t test). In linear regression analyses of the articles, the radiation activity of (11)C-cho and (18)F-FCH was not significantly associated with the detection rate of metastatic sites (P = 0.75 and P = 0.60). Restaging with radiolabeled choline PET/CT detected metastatic sites for patients with biochemical recurrence and PSA levels of 1-10 ng/mL at clinically relevant level. The choice between the two choline radiotracers and different acquisition protocols had no significant impact on detection.

Optimized protocol for (18)F-choline PET/CT in patients with biochemically relapsed prostate cancer: experiences on 250 consecutive cases

PURPOSE

We review acquisition F-choline PET/CT methodology, evaluate a new F-choline acquisition protocol for prostate cancer (PC), and propose a standardized acquisition protocol on F-choline in PC patients.

MATERIALS

Two hundred fifty consecutive PC patients (mean age 72 years, mean PSA 7.9 ng/mL) were prospectively evaluated with F-choline PET/CT. An early scan of the pelvis (1 bed position of 4 minutes) was followed by a whole-body scan at 1 hour. Early and 1 delayed hour images of the pelvis were compared.

RESULTS

Twenty-one percent of patients (n = 57) with positive F-choline demonstrated abnormal local uptake; 18% of patients (n = 45) showed distant localization only; 23% of patients (n = 53) had both local and distant localization; 38% of patients (n = 38) did not show any pathological uptake. All early images showed absence of radioactive urine in ureters, bladder, or urethra with satisfactory visualization of the prostatic region. Considering the group of patients with local uptake only, the prostatic region uptake, confirmed by late images, was better visualized in the early phase in 32/57 cases (SUVmax 12.4 ± 3.2 vs. 7.3 ± 5.2, P <0.01). Instead distant lesions were visualized on both early and late images with similar uptakes values (SUVmax 9.8 ± 4.1 vs. 10.3 ± 4.5, P = N.S.).

CONCLUSION

Early F-choline images improve pelvic prostate cancer lesion clarity. All pathologic pelvic deposits (prostate, lymph nodes, bone) were visualized both in the early and late images.

¹⁸F-fluoromethylcholine or ¹⁸F-fluoroethylcholine pet for prostate cancer imaging: which is better? A literature revision

INTRODUCTION

The present review was conceived for describing the differences in biodistribution and diagnostic performance of two types of (18)F-radiolabeled choline for positron emission tomography (PET) imaging in prostate cancer (PCa), such as fluoromethylcholine (FCH) and fluoroethylcholine (FEC).

MATERIALS AND METHODS

A collection of published data about two radiopharmaceutical agents was made by using PubMed, Web of Knowledge databases and Trip Database, and then a critical revision was discussed.

RESULTS

FCH was injected in 338 and 1164 patients, while FEC was injected in 20 and 139 patients, respectively for basal staging and re-staging. The diagnostic performances of FCH and FEC for the detection of lymph node metastasis before the surgical approach are typically around 50% or less and between 0% and 39%, respectively. Conversely, both the tracers appear useful for the detection of recurrent PCa in case of increase in absolute PSA value or in case of high levels of PSA velocity and PSA doubling time (sensitivity ranged between 42.9% and 96% for FCH and between 62% and 85.7% for FEC).

CONCLUSIONS

In according with the available information, FCH appears to be a more appropriate radiocompound as compared to FEC, although more comparative data are mandatory. A well designed and prospective trial for the evaluation of biokinetic data and diagnostic performance of both radiopharmaceutical agents seems essential.

ADVANCES IN KNOWLEDGE AND IMPLICATION FOR PATIENT CARE

FCH seems to be an appropriate radiopharmaceutical agent as compared to FEC. Anyway both the radiocompounds are useful in the evaluation of recurrent disease in case of a serial increase in PSA value and their performance improves when a correct preparation and acquisition protocol is employed.

The role of positron emission tomography/computed tomography imaging with radiolabeled choline analogues in prostate cancer

INTRODUCTION

prostate cancer is the most frequent solid malignant tumor in Western Countries. Positron emission tomography/x-ray computed tomography imaging with radiolabeled choline analogues is a useful tool for restaging prostate cancer in patients with rising prostate-specific antigen after radical treatment (in whom conventional imaging techniques have important limitations) as well as in the initial assessment of a selected group of prostate cancer patients. For this reason a literature review is necessary in order to evaluate the usefulness of this imaging test for the diagnosis and treatment of prostate cancer.

EVIDENCE ACQUISITION

a MEDLINE (PubMed way) literature search was performed using the search parameters: «Prostate cancer» and «Choline-PET/CT». Other search terms were «Biochemical failure» and/or «Staging» and/or «PSA kinetics». English and Spanish papers were selected; original articles, reviews, systematic reviews and clinical guidelines were included.

CONCLUSIONS

according to available data, radiolabeled choline analogues plays an important role in the management of prostate cancer, especially in biochemical relapse because technique accuracy is properly correlated with prostate-specific antigen values and kinetics. Although is an emerging diagnostic technique useful in treatment planning of prostate cancer, final recommendations have not been submitted.

New acquisition protocol of 18F-choline PET/CT in prostate cancer patients: review of the literature about methodology and proposal of standardization

Purpose. (1) To evaluate a new acquisition protocol of ¹⁸F-choline (FCH) PET/CT for prostate cancer patients (PC), (2) to review acquisition ¹⁸F-choline PET/CT methodology, and (3) to propose a standardized acquisition protocol on FCH PET/CT in PC patients. Materials. 100 consecutive PC patients (mean age 70.5 years, mean PSA 21.35 ng/mL) were prospectively evaluated. New protocol consisted of an early scan of the pelvis immediately after the injection of the tracer (1 bed position of 4 min) followed by a whole body scan at one 1 hour. Early and 1 hour images were compared for interfering activity and pathologic findings. Results. The overall detection rate of FCH PET/CT was 64%. The early static images of the pelvis showed absence of radioactive urine in ureters, bladder, or urethra which allowed a clean evaluation of the prostatic fossae. Uptake in the prostatic region was better visualized in the early phase in 26% (7/30) of cases. Other pelvic pathologic findings (bone and lymph nodes) were visualized in both early and late images. Conclusion. Early ¹⁸F-choline images improve visualization of abnormal uptake in prostate fossae. All pathologic pelvic deposits (prostate, lymph nodes, and bone) were visualized in both early and late images.

Contemporary role of salvage lymphadenectomy in patients with recurrence following radical prostatectomy

CONTEXT

Prostate cancer (PCa) patients with isolated clinical lymph node (LN) relapse, limited to the regional and/or retroperitoneal LNs, may represent a distinct group of patients who have a more favorable outcome than men with progression to the bone or to other visceral organs. Some data indirectly denote a beneficial impact of pelvic LN dissection on survival in these patients.

OBJECTIVE

To provide an overview of the currently available literature regarding salvage LN dissection (SLND) in PCa patients with clinical relapse limited to LNs after radical prostatectomy (RP).

EVIDENCE ACQUISITION

A systematic literature search was conducted using the Medline, Embase, and Web of Science databases to identify original articles, review articles, and editorials regarding SLND. Articles published between 2000 and 2012 were reviewed and selected with the consensus of all the authors.

EVIDENCE SYNTHESIS

Contemporary imaging techniques, such as 11C-choline positron emission tomography and diffusion-weighted magnetic resonance imaging, appear to enhance the accuracy in identifying LN relapse in patients with biochemical recurrence (BCR) and after RP. In these individuals, SLND can be considered as a treatment option. The currently available data suggest that SLND can delay clinical progression and postpone hormonal therapy in almost one-third of the patients, although the majority will have BCR. An accurate and attentive preoperative patient selection may help improve these outcomes. The most frequent complication after SLND was lymphorrhea (15.3%), followed by fever (14.5%) and ileus (11.2%). It is noteworthy that all examined cohorts originated from retrospective single-institution series, with limited sample size and short follow-up. Consequently, the current findings cannot be generalized and warrant further investigation in future prospective trials.

CONCLUSIONS

The current data suggest that SLND represents an option in patients with disease relapse limited to the LNs after RP; however, more robust data derived from well-designed clinical trials are needed to validate the role of SLND in this selected patient population.

PATIENT SUMMARY

Salvage lymph node dissection (SLND) represents a treatment option in for patients with prostate cancer relapse limited to the lymph nodes; however, more robust data derived from well-designed clinical trials are needed to validate the role of SLND in this selected patient population.

Long-term outcomes of salvage lymph node dissection for clinically recurrent prostate cancer: results of a single-institution series with a minimum follow-up of 5 years

BACKGROUND

Prostate cancer (PCa) patients with lymph node recurrence after radical prostatectomy (RP) are usually managed with androgen-deprivation therapy. Despite the absence of prospective randomized studies, salvage lymph node dissection (LND) has been proposed as an alternative treatment option.

OBJECTIVE

To examine long-term outcomes of salvage LND in patients with nodal recurrent PCa documented by 11C-choline positron emission tomography/computed tomography (PET/CT) scan.

DESIGN, SETTING, AND PARTICIPANTS

Overall, 59 patients affected by biochemical recurrence (BCR) with 11C-choline PET/CT scan with pathologic activity treated between 2002 and 2008 were included.

INTERVENTION

Pelvic and/or retroperitoneal salvage LND.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Biochemical response (BR) was defined as prostate-specific antigen (PSA) <0.2 ng/ml at 40 d after surgery. BCR for those who achieved BR was defined as a PSA >0.2 ng/ml. Clinical recurrence (CR) was defined as a positive PET/CT scan after salvage LND in the presence of a rising PSA. Kaplan-Meier curves assessed time to BCR, CR, and cancer-specific mortality (CSM). Cox regression analyses were fitted to assess predictors of CR.

RESULTS AND LIMITATIONS

Median follow-up after salvage LND was 81.1 mo. Overall, 35 patients (59.3%) achieved BR. The 8-yr BCR-free survival rate in patients with complete BR was 23%. Overall, the 8-yr CR- and CSM-free survival rates were 38% and 81%, respectively. In multivariable analyses evaluating preoperative variables, PSA at salvage LND represented the only predictor of CR (p=0.03). When postoperative variables were considered, BR and the presence of retroperitoneal lymph node metastases were significantly associated with the risk of CR (all p ≤ 0.04). Our study is limited by the lack of a control group.

CONCLUSIONS

Salvage LND may represent a therapeutic option for patients with BCR after RP and nodal pathologic uptake at 11C-choline PET/CT scan. Although most patients progressed to BCR after salvage LND, roughly 40% of them experienced CR-free survival.

PATIENT SUMMARY

Salvage lymph node dissection may represent a therapeutic option for selected patients with nodal recurrence after radical prostatectomy. Roughly 40% of men did not show any further clinical recurrence at long-term follow-up after surgery.

Choline PET or PET/CT and biochemical relapse of prostate cancer: a systematic review and meta-analysis

AIM

The increase of prostate-specific antigen (PSA) after radical retropubic prostatectomy (RP) or external beam radiotherapy (EBRT) is the most sensitive tool for detecting prostate cancer (PCa) recurrence, although this measure cannot distinguish between local, regional, or distant recurrence. The aim of this meta-analysis was to evaluate the diagnostic performance of 18F-choline and 11C-choline PET or PET/CT in detection of locoregional or distant metastases in PCa.

MATERIALS AND METHODS

Medline, Web of Knowledge, and Google Scholar search was carried out in order to select English-language articles dealing with diagnostic performance of both 18F-choline and 11C-choline PET for the detection of PCa recurrence after RP or EBRT. Articles were included only if absolute numbers of true-positive, true-negative, false-positive, and false-negative test results were available or derivable from the text and regarded local, lymph node, and distant metastases. Reviews, clinical reports, and editorial articles were excluded. All complete studies were re-analyzed thus performing a quantitative analysis.

RESULTS

From the years 2000 to 2012, we found 53 complete articles that critically evaluated the role of choline PET in restaging patients with PCa recurrence. The meta-analysis was carried out and dealt with 19 selected studies (12 studies for all sites of disease, 3 for lymph node metastases, and 4 for local recurrence), with a total of 1555 patients. The meta-analysis provided a pooled sensitivity of 85.6% (95% CI: 82.9%-88.1%) and pooled specificity of 92.6% (95% CI: 90.1%-94.6%) for all sites of disease (prostatic fossa, lymph nodes, and bone), a pooled sensitivity of 75.4% (95% CI: 66.9%-82.6%) and pooled specificity of 82% (95% CI: 68.6%-91.4%) for prostatic fossa recurrence, and a pooled sensitivity of 100% (95% CI: 90.5%-100%) and pooled specificity of 81.8% (95% CI: 48.2%-97.7%) for lymph node metastases. The heterogeneity ranged between 0.00% and 88.6%. The diagnostic odds ratios were 62.123 (95% CI: 24.783-155.72), 5.869 (95% CI: 1.818-18.946), and 138.57 (95% CI: 11.27-1703.8), respectively, for all sites of disease, local recurrence, and lymph node disease.

CONCLUSIONS

Choline PET and PET/CT represent high sensitivity and specificity techniques for the detection of locoregional and distant metastases in PCa patients with recurrence of disease. Moreover, a high diagnostic odds ratio was found for the identification of lymph node disease in patients with biochemical recurrence of PCa.

Influence of androgen deprivation therapy on choline PET/CT in recurrent prostate cancer

PURPOSE

Recurrent prostate cancer is usually treated by combining radiotherapy and androgen deprivation therapy. To stage the cancer, choline positron emission tomography (PET)/CT can be performed. It is generally thought that androgen deprivation therapy does not influence choline PET/CT. In this article we focus on the molecular backgrounds of choline and androgens, and the results of preclinical and clinical studies performed using PET/CT.

METHODS

Using PubMed, we looked for the relevant articles about androgen deprivation therapy and choline PET/CT.

RESULTS

During ADT, a tendency of decreased uptake of choline in prostate cancer was observed, in particular in hormone-naïve patients.

CONCLUSION

We conclude that in order to prevent false-negative choline PET/CT scans androgen deprivation should be withheld prior to scanning, especially in hormone-naïve patients.